/* ==========================================================================
   StudyDump - Core Editorial Stylesheet
   Aesthetic: Modern Academic Notebook + Editorial Study Library
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-text-size-adjust: 100%;
  max-width: 100%;
  overflow-x: clip;
}

/* Lenis Smooth Scroll Integration & Optimization */
html.lenis,
html.lenis body {
  height: auto;
}

html.lenis {
  scroll-behavior: auto !important;
}

.lenis:not(.lenis-autoToggle).lenis-stopped {
  overflow: clip;
}

.lenis [data-lenis-prevent],
.lenis [data-lenis-prevent-wheel],
.lenis [data-lenis-prevent-touch],
.lenis [data-lenis-prevent-vertical],
.lenis [data-lenis-prevent-horizontal] {
  overscroll-behavior: contain;
}

.lenis.lenis-smooth iframe {
  pointer-events: none;
}

.lenis.lenis-autoToggle {
  transition-property: overflow;
  transition-duration: 1ms;
  transition-behavior: allow-discrete;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  line-height: var(--leading-normal);
  font-size: var(--text-base);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  max-width: 100%;
  overflow-x: clip;
}

@supports not (overflow-x: clip) {
  html, body {
    overflow-x: hidden;
  }
}

img, video, canvas {
  max-width: 100%;
  height: auto;
}

::selection {
  background-color: var(--accent-subtle);
  color: var(--accent);
}

a {
  color: inherit;
  text-decoration: none;
  touch-action: manipulation;
  transition: color var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
  touch-action: manipulation;
}

:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: var(--radius-xs);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  background: var(--text-primary);
  color: var(--text-inverse);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-xs);
  z-index: 1000;
  max-width: calc(100% - 2 * var(--space-4));
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
}

/* ==========================================================================
   Simple Top Header
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--bg-app);
  border-bottom: 1px solid var(--border-subtle);
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
  transform: translateZ(0);
}

.header-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 58px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  text-decoration: none;
  touch-action: manipulation;
  padding: 4px 0;
}

.brand-title {
  font-family: var(--font-editorial);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-search-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  height: 38px;
  min-height: 38px;
  padding: 0 12px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  font-weight: 500;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.header-search-btn:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.header-search-btn svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.header-search-text {
  font-size: var(--text-xs);
}

.header-search-kbd {
  font-family: var(--font-mono);
  font-size: var(--text-3xs);
  color: var(--text-tertiary);
  background-color: var(--bg-app);
  border: 1px solid var(--border-default);
  padding: 1px 4px;
  border-radius: 2px;
  margin-left: 2px;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  min-width: 38px;
  min-height: 38px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.theme-toggle svg {
  width: 16px;
  height: 16px;
}

/* ==========================================================================
   Homepage Container & Spacing
   ========================================================================== */

.page-container {
  max-width: var(--container-max);
  width: 100%;
  margin: 0 auto;
  padding: var(--space-8) var(--space-6) var(--space-20);
  flex: 1;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   2. Semester Identity & Natural Editorial Intro
   ========================================================================== */

.home-intro-section {
  margin-bottom: var(--space-8);
}

.hero-curator-banner {
  display: inline-flex;
  align-items: center;
  flex-wrap: nowrap;
  white-space: nowrap;
  max-width: 100%;
  gap: var(--space-2);
  padding: 4px 12px 4px 5px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
  box-shadow: var(--shadow-subtle);
  transition: border-color var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast);
}

.hero-curator-banner:hover {
  border-color: var(--accent-border);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.06);
}

.hero-curator-banner .dot-sep {
  margin: 0;
  font-size: 0.9em;
  opacity: 0.7;
}

.hero-curator-banner > * {
  flex-shrink: 0;
}

.curator-pill {
  display: inline-block;
  padding: 2px 8px;
  background-color: var(--accent-subtle);
  color: var(--accent);
  font-size: var(--text-3xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-radius: var(--radius-pill);
}

.hero-curator-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--text-primary);
  font-weight: 600;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.hero-curator-link:hover {
  color: var(--accent);
  text-decoration: underline;
}

.hero-curator-link svg {
  stroke: currentColor;
  transition: transform var(--transition-fast);
}

.hero-curator-link:hover svg {
  transform: translate(1px, -1px);
}

.curator-class-tag {
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  font-weight: 500;
}

.intro-semester-meta {
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-tertiary);
  margin-bottom: var(--space-3);
  letter-spacing: 0.01em;
}

.intro-heading {
  font-family: var(--font-editorial);
  font-size: clamp(2rem, 4.5vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  max-width: 22ch;
}

/* ==========================================================================
   3. Prominent Search Field
   ========================================================================== */

.home-search-section {
  margin-bottom: var(--space-12);
}

.search-field-box {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px 16px;
  min-height: 48px;
  width: 100%;
  max-width: 100%;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.search-field-box:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

.search-field-icon {
  width: 17px;
  height: 17px;
  stroke: var(--text-tertiary);
  flex-shrink: 0;
  transition: stroke var(--transition-fast);
}

.search-field-box:focus-within .search-field-icon {
  stroke: var(--accent);
}

.search-field-input {
  flex: 1;
  min-width: 0;
  background: transparent;
  border: none;
  outline: none;
  font-family: var(--font-sans);
  font-size: 1rem; /* 16px to prevent iOS Safari auto-zoom */
  color: var(--text-primary);
  font-weight: 400;
}

.search-field-input::placeholder {
  color: var(--text-tertiary);
  font-size: 0.9375rem;
}

.search-field-shortcut {
  font-family: var(--font-mono);
  font-size: var(--text-3xs);
  color: var(--text-tertiary);
  background-color: var(--bg-app);
  border: 1px solid var(--border-default);
  padding: 1px 5px;
  border-radius: 2px;
}

.search-field-clear-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  min-width: 24px;
  padding: 0;
  background-color: var(--bg-surface-subtle);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.search-field-clear-btn.visible {
  display: inline-flex !important;
}

.search-field-clear-btn:hover {
  color: var(--text-primary);
  background-color: var(--bg-surface);
  border-color: var(--border-hover);
}

.search-field-clear-btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.search-field-clear-btn svg {
  width: 12px;
  height: 12px;
}

/* Section Tag / Eyebrow */
.section-eyebrow {
  font-family: var(--font-sans);
  font-size: var(--text-2xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
  color: var(--text-tertiary);
  margin-bottom: var(--space-4);
}

/* ==========================================================================
   4. Academic Context Bar
   ========================================================================== */

.academic-context-section {
  margin-bottom: var(--space-10);
}

.academic-context-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: 10px 14px;
  max-width: 100%;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
}

.academic-context-left {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  min-width: 0;
  max-width: 100%;
}

.context-label {
  font-family: var(--font-mono);
  text-transform: uppercase;
  font-size: var(--text-3xs);
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  font-weight: 600;
}

.context-divider {
  color: var(--border-strong);
}

.context-val {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--text-primary);
  overflow-wrap: break-word;
  word-break: break-word;
}

.context-year {
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  color: var(--text-secondary);
}

/* ==========================================================================
   5. Browse by Resource Type
   ========================================================================== */

.browse-types-section {
  margin-bottom: var(--space-8);
}

.browse-types-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-2);
}

@media (max-width: 960px) {
  .browse-types-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 640px) {
  .browse-types-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 380px) {
  .browse-types-grid {
    grid-template-columns: 1fr;
  }
}

.browse-type-card {
  display: flex;
  flex-direction: column;
  padding: 10px 12px;
  min-height: 52px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  text-decoration: none;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.browse-type-card:hover {
  border-color: var(--accent);
  background-color: var(--bg-surface-hover);
}

.browse-type-name {
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-primary);
  line-height: var(--leading-snug);
  transition: color var(--transition-fast);
}

.browse-type-card:hover .browse-type-name {
  color: var(--accent);
}

.browse-type-desc {
  font-size: var(--text-3xs);
  color: var(--text-tertiary);
  line-height: 1.3;
  margin-top: 2px;
}

/* ==========================================================================
   6. Subjects Directory (Main Section)
   Editorial rows with numbers, typography, and clean resource counts
   ========================================================================== */

.subjects-section {
  margin-bottom: var(--space-16);
}

.subjects-list {
  display: flex;
  flex-direction: column;
}

.subject-row {
  display: flex;
  flex-direction: column;
  padding: var(--space-8) 0;
  border-bottom: 1px solid var(--border-default);
  cursor: pointer;
}

.subject-row:first-child {
  border-top: 1px solid var(--border-default);
}

.subject-num {
  font-family: var(--font-editorial);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text-tertiary);
  margin-bottom: var(--space-1);
}

.subject-row-main {
  display: flex;
  flex-direction: column;
  margin-bottom: var(--space-3);
}

.subject-row-title {
  font-family: var(--font-editorial);
  font-size: clamp(1.65rem, 3.5vw, 2.1rem);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-decoration: none;
  margin-bottom: 2px;
  transition: color var(--transition-fast);
}

.subject-row-code {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
}

.subject-row-bottom {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.subject-row-stats {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

.subject-row-link {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition-fast);
}

.subject-row:hover .subject-row-title,
.subject-row:focus-within .subject-row-title {
  color: var(--accent);
}

.subject-row:hover .subject-row-link,
.subject-row:focus-within .subject-row-link {
  text-decoration: underline;
}

/* ==========================================================================
   7. Latest Additions (Automated from manifest)
   ========================================================================== */

.latest-additions-section {
  margin-bottom: var(--space-12);
}

.latest-additions-list {
  display: flex;
  flex-direction: column;
}

.addition-row {
  display: grid;
  grid-template-columns: 85px 1fr auto;
  align-items: baseline;
  padding: 12px 0;
  border-bottom: 1px solid var(--border-subtle);
  gap: var(--space-4);
}

.addition-row:first-child {
  border-top: 1px solid var(--border-subtle);
}

.addition-date {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

.addition-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.addition-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  overflow-wrap: break-word;
  word-break: break-word;
  transition: color var(--transition-fast);
}

.addition-row:hover .addition-title {
  color: var(--accent);
}

.addition-meta {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  overflow-wrap: break-word;
  word-break: break-word;
}

.addition-action {
  white-space: nowrap;
}

.addition-link {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
}

.addition-link:hover {
  text-decoration: underline;
}

@media (max-width: 640px) {
  .addition-row {
    grid-template-columns: 70px 1fr;
    gap: var(--space-2);
  }
  .addition-action {
    display: none;
  }
}

/* ==========================================================================
   Colophon Footer
   ========================================================================== */

.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-default);
  padding: var(--space-12) var(--space-6) var(--space-8);
  font-size: var(--text-xs);
  color: var(--text-secondary);
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.footer-top {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
  justify-content: space-between;
}

@media (min-width: 640px) {
  .footer-top {
    flex-direction: row;
    align-items: flex-start;
    gap: var(--space-8);
  }
}

.footer-brand-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  max-width: 320px;
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.015em;
}

.footer-summary {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  line-height: var(--leading-normal);
}

.footer-right-group {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-3);
}

@media (min-width: 640px) {
  .footer-right-group {
    align-items: flex-end;
  }
}

/* Footer Personal Details Card (Subtle / Not-too-highlighty) */
.footer-personal-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 250px;
  max-width: 320px;
  width: 100%;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}

.footer-personal-card:hover {
  border-color: var(--border-medium);
}

.personal-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.personal-card-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.personal-card-tag {
  font-size: var(--text-3xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-quaternary);
  line-height: 1;
}

.personal-card-name {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}

.personal-card-batch {
  font-size: 10px;
  font-weight: 600;
  color: var(--text-tertiary);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  padding: 2px 7px;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.personal-card-links {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 8px;
  border-top: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.personal-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11.5px;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.personal-link:hover {
  color: var(--accent);
}

.personal-link svg {
  flex-shrink: 0;
  stroke: var(--text-tertiary);
  transition: stroke var(--transition-fast);
}

.personal-link:hover svg {
  stroke: var(--accent);
}

.personal-arrow {
  opacity: 0.6;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.personal-link:hover .personal-arrow {
  opacity: 1;
  transform: translate(1px, -1px);
}

/* Footer Visitor Counter Badge */
.footer-visitor-cell {
  position: relative;
}

.footer-visitor-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 3px 9px 3px 7px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  transition: border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
  cursor: default;
  user-select: none;
}

.footer-visitor-badge:hover {
  border-color: var(--border-medium);
  background: var(--bg-elevated);
  transform: translateY(-1px);
}

.visitor-pulse-dot {
  position: relative;
  display: inline-block;
  width: 7px;
  height: 7px;
  background-color: #10b981;
  border-radius: 50%;
  flex-shrink: 0;
}


.visitor-count-val {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.visitor-label-text {
  font-size: 11px;
  color: var(--text-tertiary);
  margin-left: -2px;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  padding-top: var(--space-5);
  border-top: 1px solid var(--border-subtle);
}

.footer-bottom-left {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-3);
}

.footer-note {
  font-size: var(--text-3xs);
  color: var(--text-quaternary);
}

.footer-legal-links {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.footer-legal-link {
  font-size: var(--text-3xs);
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-legal-link:hover {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.footer-legal-sep {
  font-size: var(--text-3xs);
  color: var(--text-quaternary);
  user-select: none;
}

.footer-top-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: var(--text-3xs);
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  transition: color var(--transition-fast);
}

.footer-top-btn:hover {
  color: var(--text-primary);
}

/* ==========================================================================
   Responsive Adaptations (Tablets & Mobile Devices)
   ========================================================================== */

/* Tablet & Smaller Screens (max-width: 1023px) */
@media (max-width: 1023px) {
  .page-container {
    padding: var(--space-6) max(var(--space-6), var(--safe-right)) var(--space-16) max(var(--space-6), var(--safe-left));
  }
}

/* Mobile Devices (max-width: 768px) */
@media (max-width: 768px) {
  .header-inner {
    position: relative;
    padding: 6px max(12px, var(--safe-right)) 6px max(12px, var(--safe-left));
    min-height: 48px;
    gap: 8px;
  }

  .semester-switcher-wrapper {
    position: static;
  }

  .semester-dropdown {
    top: calc(100% + 4px);
    left: auto;
    right: max(12px, var(--safe-right));
    width: min(290px, calc(100vw - 24px));
    max-width: calc(100vw - 24px);
  }

  .brand-title {
    font-size: 1.2rem;
    white-space: nowrap;
  }

  .header-actions {
    gap: 4px;
    flex-shrink: 0;
  }

  .semester-switcher-btn {
    height: 34px;
    min-height: 34px;
    padding: 0 8px;
    gap: 4px;
    font-size: 12px;
  }

  .semester-chevron {
    width: 9px;
    height: 9px;
  }

  .header-search-btn {
    width: 34px;
    height: 34px;
    min-width: 34px;
    min-height: 34px;
    padding: 0;
    justify-content: center;
  }

  .header-search-text,
  .header-search-kbd {
    display: none !important;
  }

  .header-bookmarks-btn {
    width: 34px;
    height: 34px;
    min-width: 34px;
    min-height: 34px;
    padding: 0;
    justify-content: center;
  }

  .header-bookmarks-count {
    top: -3px;
    right: -3px;
    min-width: 15px;
    height: 15px;
    font-size: 0.62rem;
    padding: 0 3px;
  }

  .theme-toggle {
    width: 34px;
    height: 34px;
    min-width: 34px;
    min-height: 34px;
    padding: 0;
    justify-content: center;
  }

  .header-flashcards-btn {
    width: 34px;
    height: 34px;
    min-width: 34px;
    min-height: 34px;
    padding: 0;
    justify-content: center;
  }

  .header-flashcards-text {
    display: none !important;
  }

  .header-share-btn {
    width: 34px;
    height: 34px;
    min-width: 34px;
    min-height: 34px;
    padding: 0;
    justify-content: center;
  }

  .header-share-text {
    display: none !important;
  }

  .page-container {
    padding: var(--space-4) max(14px, var(--safe-right)) var(--space-12) max(14px, var(--safe-left));
  }

  .hero-curator-banner {
    flex-wrap: nowrap;
    white-space: nowrap;
    gap: 6px;
    padding: 3px 10px 3px 4px;
    font-size: var(--text-2xs);
    margin-bottom: var(--space-3);
    max-width: 100%;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    box-sizing: border-box;
  }

  .hero-curator-banner::-webkit-scrollbar {
    display: none;
  }

  .hero-curator-banner .curator-pill {
    padding: 2px 7px;
    font-size: 0.65rem;
    letter-spacing: 0.05em;
  }

  .hero-curator-banner .hero-curator-link {
    font-size: var(--text-2xs);
    gap: 3px;
  }

  .hero-curator-banner .hero-curator-link svg {
    width: 10px;
    height: 10px;
  }

  .hero-curator-banner .curator-class-tag {
    font-size: 0.7rem;
  }

  .intro-heading {
    font-size: clamp(1.5rem, 5.5vw, 2.05rem);
    line-height: 1.22;
    max-width: 100%;
    overflow-wrap: break-word;
    word-break: break-word;
  }

  .desktop-break {
    display: none;
  }

  .intro-subheading {
    font-size: var(--text-xs);
    line-height: 1.65;
    overflow-wrap: break-word;
    word-break: break-word;
  }

  .intro-subheading .dot-sep {
    margin: 0 0.35rem;
  }

  .home-search-section {
    margin-bottom: var(--space-8);
  }

  .search-field-box {
    padding: 8px 12px;
  }

  .search-field-shortcut {
    display: none;
  }

  .academic-context-section {
    margin-bottom: var(--space-8);
  }

  .subject-row {
    padding: var(--space-5) 0;
  }

  .subject-row-title {
    font-size: 1.35rem;
    overflow-wrap: break-word;
    word-break: break-word;
  }

  .subject-row-bottom {
    gap: var(--space-2);
    flex-direction: column;
    align-items: flex-start;
  }

  .subject-row-link {
    margin-top: 2px;
    padding: 4px 0;
  }

  .footer-inner {
    gap: var(--space-6);
  }

  .footer-info-grid {
    gap: var(--space-4) var(--space-6);
  }

  .footer-cell-val,
  .footer-curator-link {
    white-space: normal;
  }

  .footer-top-btn {
    padding: 6px 0;
    min-height: 36px;
  }
}

/* Extra Small Phones (max-width: 380px) */
@media (max-width: 380px) {
  .header-inner {
    padding-left: max(8px, var(--safe-left));
    padding-right: max(8px, var(--safe-right));
    gap: 4px;
  }

  .page-container {
    padding-left: max(10px, var(--safe-left));
    padding-right: max(10px, var(--safe-right));
  }

  .brand-title {
    font-size: 1.1rem;
  }

  .header-actions {
    gap: 3px;
  }

  .semester-switcher-btn {
    padding: 0 5px;
    font-size: 11px;
    gap: 3px;
  }

  .header-search-btn,
  .header-bookmarks-btn,
  .theme-toggle,
  .header-flashcards-btn {
    width: 32px;
    height: 32px;
    min-width: 32px;
    min-height: 32px;
  }

  .header-share-btn {
    display: none !important;
  }

  .intro-heading {
    font-size: 1.4rem;
  }

  .addition-row {
    grid-template-columns: 50px 1fr;
    gap: var(--space-2);
  }

  .addition-date {
    font-size: var(--text-2xs);
  }

  .academic-context-bar {
    padding: 8px 10px;
    font-size: var(--text-2xs);
  }
}

/* ==========================================================================
   Header Bookmarks & Offline Status Badges
   ========================================================================== */

.header-bookmarks-btn {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  min-width: 38px;
  min-height: 38px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.header-bookmarks-btn:hover {
  border-color: var(--border-strong);
  color: var(--accent);
}

.header-bookmarks-count {
  position: absolute;
  top: -4px;
  right: -4px;
  min-width: 17px;
  height: 17px;
  padding: 0 4px;
  border-radius: 999px;
  background-color: var(--accent);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.header-share-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  height: 38px;
  min-height: 38px;
  padding: 0 0.75rem;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.header-share-btn:hover {
  border-color: var(--border-strong);
  color: var(--accent);
  background-color: var(--bg-surface-elevated);
}

.header-share-btn.share-btn-copied {
  border-color: var(--success, #10b981);
  color: var(--success, #10b981);
  background-color: rgba(16, 185, 129, 0.12);
}

@media (max-width: 640px) {
  .header-share-btn {
    display: none !important;
  }
}

/* Share success toast */
.share-success-toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(30px);
  z-index: 1100;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.75rem 1.25rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-pill);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-primary);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
  white-space: nowrap;
}

.share-success-toast svg {
  color: var(--success, #10b981);
  flex-shrink: 0;
}

.share-success-toast.toast-visible {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 640px) {
  .share-success-toast {
    bottom: 1.25rem;
    left: 1rem;
    right: 1rem;
    transform: translateY(30px);
    border-radius: var(--radius-md);
    white-space: normal;
    text-align: center;
    justify-content: center;
  }
  .share-success-toast.toast-visible {
    transform: translateY(0);
  }
}

.offline-status-indicator {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  font-weight: 600;
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.25);
  padding: 3px 8px;
  border-radius: 999px;
  letter-spacing: 0.02em;
}

/* ==========================================================================
   Bookmarks Drawer / Dialog Modal
   ========================================================================== */

.bookmarks-dialog {
  border: none;
  background: transparent;
  padding: 0;
  margin: 0;
  max-width: none;
  max-height: none;
  width: 100vw;
  height: 100vh;
  position: fixed;
  inset: 0;
  z-index: 1000;
}

.bookmarks-dialog::backdrop {
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  animation: fadeIn 0.15s ease-out;
}

.bookmarks-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 100%;
  max-width: 440px;
  height: 100%;
  background: var(--bg-surface);
  border-left: 1px solid var(--border-default);
  box-shadow: -8px 0 30px rgba(0, 0, 0, 0.25);
  display: flex;
  flex-direction: column;
  animation: slideInRight 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
  }
  to {
    transform: translateX(0);
  }
}

.bookmarks-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-surface);
}

.bookmarks-title-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.bookmarks-title-row svg {
  color: var(--accent);
}

.bookmarks-title-row h2 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.bookmarks-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  background: var(--accent-subtle);
  color: var(--accent);
  padding: 2px 7px;
  border-radius: 999px;
}

.bookmarks-close-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  min-height: 36px;
  transition: all var(--transition-fast);
}

.bookmarks-close-btn svg {
  width: 20px;
  height: 20px;
  display: block;
}

.bookmarks-close-btn:hover {
  color: var(--text-primary);
  background: var(--bg-surface-subtle);
  border-color: var(--border-default);
}

.bookmarks-close-btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.bookmarks-content {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
}

.bookmarks-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 3.5rem 1.5rem;
  margin: auto;
}

.bookmarks-empty-icon {
  color: var(--text-tertiary);
  margin-bottom: 1rem;
  opacity: 0.6;
}

.bookmarks-empty-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.bookmarks-empty-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  max-width: 280px;
}

.bookmarks-empty-close-btn {
  margin-top: 1.25rem;
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-default);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 6px 18px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.bookmarks-empty-close-btn:hover {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.bookmarks-items-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.bookmark-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.bookmark-card:hover {
  border-color: var(--border-default);
  transform: translateY(-1px);
}

.bookmark-card-link {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  text-decoration: none;
  min-width: 0;
  flex: 1;
}

.bookmark-card-meta {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.bookmark-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 1px 5px;
  border-radius: 3px;
  text-transform: uppercase;
}

.bookmark-unit {
  font-size: 0.72rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

.bookmark-card-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
  transition: color var(--transition-fast);
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.bookmark-card:hover .bookmark-card-title {
  color: var(--accent);
}

.bookmark-delete-btn {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 6px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast), background-color var(--transition-fast);
  flex-shrink: 0;
}

.bookmark-delete-btn:hover {
  color: #ef4444;
  background: rgba(239, 68, 68, 0.1);
}

.bookmarks-footer-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1.25rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border-subtle);
}

.bookmarks-footer-info {
  font-size: 0.8rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.bookmarks-footer-btn-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.bookmarks-clear-all-btn {
  background: transparent;
  border: none;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
  transition: color var(--transition-fast);
}

.bookmarks-clear-all-btn:hover {
  color: #ef4444;
  text-decoration: underline;
}

.bookmarks-footer-done-btn {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-default);
  color: var(--text-primary);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.bookmarks-footer-done-btn:hover {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

/* ==========================================================================
   Toast Notification System
   ========================================================================== */
.studydump-toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 99999;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
  max-width: calc(100vw - 48px);
}

.studydump-toast {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 18px;
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35), 0 4px 10px rgba(0, 0, 0, 0.2);
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  font-weight: 500;
  line-height: 1.4;
  opacity: 0;
  transform: translateY(14px) scale(0.95);
  transition: opacity 0.25s cubic-bezier(0.16, 1, 0.3, 1), transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.studydump-toast.toast-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.studydump-toast-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--accent);
}

.studydump-toast.toast-success .studydump-toast-icon {
  color: #10b981;
}

.studydump-toast.toast-info .studydump-toast-icon {
  color: var(--accent);
}

.studydump-toast-text {
  flex-grow: 1;
}

/* Instagram Follow Developer Card Toast */
.studydump-follow-card {
  position: relative;
  width: 360px;
  max-width: 100%;
  padding: 16px 18px 18px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-lg);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.32), 0 4px 12px rgba(0, 0, 0, 0.16);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  overflow: hidden;
  opacity: 0;
  transform: translateY(20px) scale(0.96);
  transition: opacity 0.35s cubic-bezier(0.16, 1, 0.3, 1), transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
  font-family: var(--font-sans);
}

.studydump-follow-card.card-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.follow-card-glow {
  position: absolute;
  top: -40px;
  right: -40px;
  width: 130px;
  height: 130px;
  background: radial-gradient(circle, rgba(225, 48, 108, 0.28) 0%, rgba(245, 96, 64, 0.12) 50%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  filter: blur(18px);
}

.follow-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.follow-card-avatar {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  flex-shrink: 0;
  box-shadow: 0 4px 12px rgba(220, 39, 67, 0.35);
}

.follow-card-meta {
  flex: 1;
  min-width: 0;
}

.follow-card-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #e1306c;
  line-height: 1;
  margin-bottom: 3px;
}

.follow-card-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.25;
  margin: 0;
}

.follow-card-close {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.follow-card-close:hover {
  color: var(--text-primary);
  background: var(--bg-surface);
}

.follow-card-desc {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  line-height: 1.45;
  margin: 0 0 14px 0;
}

.follow-card-desc strong {
  color: var(--text-primary);
}

.follow-card-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.follow-card-btn-primary {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-md);
  background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
  color: #ffffff !important;
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: 0 4px 14px rgba(220, 39, 67, 0.35);
}

.follow-card-btn-primary:hover {
  opacity: 0.94;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(220, 39, 67, 0.45);
}

.follow-card-btn-primary .follow-ext-arrow {
  transition: transform var(--transition-fast);
}

.follow-card-btn-primary:hover .follow-ext-arrow {
  transform: translate(1px, -1px);
}

.follow-card-btn-secondary {
  padding: 8px 12px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-tertiary);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.follow-card-btn-secondary:hover {
  background: var(--bg-hover);
  color: var(--text-secondary);
  border-color: var(--border-medium);
}

@media (max-width: 640px) {
  .studydump-toast-container {
    bottom: 16px;
    right: 16px;
    left: 16px;
    align-items: center;
  }
  .studydump-toast {
    width: 100%;
    justify-content: center;
  }
  .studydump-follow-card {
    width: 100%;
  }
}

/* ==========================================================================
   Multi-Semester Switcher Component (Temporarily hidden)
   ========================================================================== */

.semester-switcher-wrapper {
  display: none !important;
  position: relative;
}

.semester-switcher-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 38px;
  min-height: 38px;
  padding: 0 10px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-size: var(--text-xs);
  font-weight: 600;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.semester-switcher-btn:hover {
  border-color: var(--border-strong);
  background-color: var(--bg-hover);
}

.semester-chevron {
  transition: transform var(--transition-fast);
  color: var(--text-tertiary);
}

.semester-switcher-wrapper.open .semester-chevron {
  transform: rotate(180deg);
}

.semester-dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  width: 290px;
  max-width: min(290px, calc(100vw - 24px));
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-modal);
  z-index: 1100;
  opacity: 0;
  transform: translateY(-8px) scale(0.97);
  pointer-events: none;
  transition: opacity 0.18s cubic-bezier(0.16, 1, 0.3, 1), transform 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

[data-theme="dark"] .semester-dropdown {
  background-color: var(--bg-surface-elevated);
  border-color: var(--border-default);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.65), 0 0 0 1px var(--border-default);
}

.semester-switcher-wrapper.open .semester-dropdown {
  display: block;
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.semester-dropdown-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-default);
  background-color: var(--bg-surface);
}

.semester-dropdown-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
}

.semester-dropdown-batch {
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-subtle);
  border: 1px solid var(--accent-border);
  padding: 1px 7px;
  border-radius: var(--radius-pill);
}

.semester-dropdown-list {
  padding: 6px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-height: 280px;
  overflow-y: auto;
  background-color: var(--bg-surface-elevated);
}

.semester-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  background-color: transparent;
  transition: background-color var(--transition-fast);
  user-select: none;
}

.semester-option:hover {
  background-color: var(--bg-surface-subtle);
}

.semester-option.active {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
}

.sem-option-icon {
  margin-top: 3px;
  flex-shrink: 0;
  color: var(--text-tertiary);
}

.sem-pulse-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 6px rgba(16, 185, 129, 0.8);
}

.sem-option-text {
  flex: 1;
  min-width: 0;
}

.sem-option-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  margin-bottom: 2px;
}

.sem-option-title {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-primary);
}

.sem-status-badge {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 1px 6px;
  border-radius: var(--radius-pill);
}

.badge-active {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
}

.badge-upcoming {
  background-color: var(--bg-surface-subtle);
  color: var(--text-tertiary);
  border: 1px solid var(--border-subtle);
}

.sem-option-desc {
  display: block;
  font-size: 11px;
  color: var(--text-tertiary);
  line-height: 1.35;
}

.semester-dropdown-footer {
  padding: 8px 12px;
  font-size: 11px;
  color: var(--text-quaternary);
  text-align: center;
  border-top: 1px solid var(--border-default);
  background-color: var(--bg-surface);
}

/* ==========================================================================
   Header Flashcards Button
   ========================================================================== */

.header-flashcards-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 38px;
  min-height: 38px;
  padding: 0 11px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
}

.header-flashcards-btn:hover {
  border-color: var(--accent);
  color: var(--text-primary);
  background-color: var(--bg-hover);
}

.header-flashcards-btn svg {
  color: var(--accent);
}

@media (max-width: 600px) {
  .header-flashcards-text {
    display: none;
  }
  .header-flashcards-btn {
    padding: 0 10px;
  }
}

/* ==========================================================================
   Full-Screen Flashcards Engine & Modal Dialog (100vw x 100vh)
   ========================================================================== */

/* Full-Screen Native Dialog Container */
.flashcards-dialog {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  max-width: 100vw;
  max-height: 100vh;
  max-height: 100dvh;
  margin: 0;
  padding: 0;
  border: none;
  background: var(--bg-app);
  color: var(--text-primary);
  z-index: 99999;
  overflow: hidden;
  overscroll-behavior: none !important;
  touch-action: none;
}

.flashcards-dialog::backdrop {
  background: var(--bg-app);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.flashcards-dialog-body {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  overscroll-behavior: none !important;
}

/* Prevent underlying page scroll when flashcards full-screen is open on all devices (iOS Safari, Android Chrome, Desktop) */
html.fc-fullscreen-open {
  overflow: hidden !important;
  height: 100% !important;
  overscroll-behavior: none !important;
  -webkit-overflow-scrolling: auto !important;
}

body.fc-fullscreen-open {
  position: fixed !important;
  top: calc(var(--fc-scroll-y, 0px) * -1) !important;
  left: 0 !important;
  right: 0 !important;
  width: 100% !important;
  height: 100% !important;
  overflow: hidden !important;
  overscroll-behavior: none !important;
  touch-action: none !important;
  padding-right: var(--fc-scrollbar-width, 0px) !important;
}

/* ==========================================================================
   Active Recall Flashcards - Coming Soon Blurred Lock & Unbypassable Modal
   StudyDump Academic Editorial Design Language
   ========================================================================== */

/* Blur the background when coming-soon lock is active with light/dark theme adaptation */
body.fc-coming-soon-active > *:not(#fc-coming-soon-overlay):not(script):not(style) {
  filter: blur(14px) brightness(0.65) saturate(1.1) !important;
  -webkit-filter: blur(14px) brightness(0.65) saturate(1.1) !important;
  opacity: 0.3 !important;
  pointer-events: none !important;
  user-select: none !important;
  transition: filter var(--transition-normal, 0.22s ease), opacity var(--transition-normal, 0.22s ease);
}

[data-theme="light"] body.fc-coming-soon-active > *:not(#fc-coming-soon-overlay):not(script):not(style) {
  filter: blur(12px) brightness(0.92) !important;
  -webkit-filter: blur(12px) brightness(0.92) !important;
  opacity: 0.35 !important;
}

/* Also blur dialog content if opened */
.flashcards-dialog.fc-coming-soon-blur .flashcards-dialog-body {
  filter: blur(14px) brightness(0.65) saturate(1.1) !important;
  -webkit-filter: blur(14px) brightness(0.65) saturate(1.1) !important;
  opacity: 0.2 !important;
  pointer-events: none !important;
  user-select: none !important;
}

/* Fullscreen Unbypassable Overlay */
.fc-coming-soon-overlay {
  position: fixed !important;
  inset: 0 !important;
  width: 100vw !important;
  height: 100vh !important;
  height: 100dvh !important;
  z-index: 99999999 !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  padding: 24px 16px !important;
  box-sizing: border-box !important;
  overflow-y: auto !important;
  overflow-x: hidden !important;
  overscroll-behavior: none !important;
  touch-action: pan-y !important;
  -webkit-overflow-scrolling: touch !important;
}

.fc-coming-soon-backdrop {
  position: fixed !important;
  inset: 0 !important;
  background: rgba(13, 15, 18, 0.72) !important;
  backdrop-filter: blur(12px) saturate(1.15) !important;
  -webkit-backdrop-filter: blur(12px) saturate(1.15) !important;
  z-index: 1 !important;
  pointer-events: all !important;
}

[data-theme="light"] .fc-coming-soon-backdrop {
  background: rgba(24, 24, 22, 0.48) !important;
}

/* StudyDump Editorial Card Layout */
.fc-coming-soon-card {
  position: relative !important;
  z-index: 2 !important;
  width: 100% !important;
  max-width: 440px !important;
  background: var(--bg-surface-elevated) !important;
  border: 1px solid var(--border-default) !important;
  border-radius: var(--radius-md, 8px) !important;
  box-shadow: var(--shadow-modal) !important;
  display: flex !important;
  flex-direction: column !important;
  overflow: hidden !important;
  color: var(--text-primary) !important;
  box-sizing: border-box !important;
  animation: fcCsPopIn 0.22s cubic-bezier(0.16, 1, 0.3, 1) forwards !important;
}

@keyframes fcCsPopIn {
  from {
    opacity: 0;
    transform: scale(0.96) translateY(8px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

/* Card Header Section */
.fc-coming-soon-header {
  padding: 22px 24px 18px !important;
  border-bottom: 1px solid var(--border-subtle) !important;
  background: var(--bg-surface) !important;
  display: flex !important;
  flex-direction: column !important;
  gap: 12px !important;
}

.fc-coming-soon-badge-row {
  display: flex !important;
  align-items: center !important;
  gap: 8px !important;
  flex-wrap: wrap !important;
}

.fc-coming-soon-badge-row .curator-pill {
  font-family: var(--font-mono) !important;
  font-size: var(--text-3xs, 11px) !important;
  font-weight: 700 !important;
  text-transform: uppercase !important;
  letter-spacing: 0.08em !important;
  background: var(--accent-subtle) !important;
  border: 1px solid var(--accent-border) !important;
  color: var(--accent) !important;
  padding: 2px 8px !important;
  border-radius: var(--radius-pill) !important;
  line-height: 1.5 !important;
}

.fc-coming-soon-badge-row .dot-sep {
  color: var(--text-quaternary) !important;
  font-size: 11px !important;
}

.fc-cs-sem-tag {
  font-family: var(--font-mono) !important;
  font-size: var(--text-3xs, 11px) !important;
  font-weight: 600 !important;
  color: var(--text-secondary) !important;
  background: var(--bg-surface-subtle) !important;
  border: 1px solid var(--border-subtle) !important;
  padding: 2px 7px !important;
  border-radius: var(--radius-sm, 4px) !important;
}

.fc-cs-title-wrap {
  display: flex !important;
  align-items: flex-start !important;
  gap: 14px !important;
}

.fc-cs-icon-badge {
  width: 42px !important;
  height: 42px !important;
  border-radius: var(--radius-sm, 6px) !important;
  background: var(--accent-subtle) !important;
  border: 1px solid var(--accent-border) !important;
  color: var(--accent) !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  flex-shrink: 0 !important;
  margin-top: 2px !important;
}

.fc-cs-title {
  font-family: var(--font-display, var(--font-sans)) !important;
  font-size: var(--text-xl, 1.35rem) !important;
  font-weight: 700 !important;
  color: var(--text-primary) !important;
  margin: 0 0 4px !important;
  line-height: var(--leading-tight, 1.25) !important;
  letter-spacing: -0.015em !important;
}

.fc-cs-subtitle {
  font-family: var(--font-sans) !important;
  font-size: var(--text-xs, 0.8125rem) !important;
  line-height: var(--leading-snug, 1.45) !important;
  color: var(--text-secondary) !important;
  margin: 0 !important;
}

/* Card Body Section */
.fc-coming-soon-body {
  padding: 20px 24px 18px !important;
  display: flex !important;
  flex-direction: column !important;
  gap: 12px !important;
}

.fc-cs-editorial-note {
  font-family: var(--font-sans) !important;
  font-size: var(--text-sm, 0.875rem) !important;
  line-height: var(--leading-normal, 1.6) !important;
  color: var(--text-secondary) !important;
  margin: 0 !important;
}

/* Actions Section */
.fc-coming-soon-actions {
  padding: 0 24px 18px !important;
  display: flex !important;
  align-items: center !important;
  gap: 10px !important;
  flex-wrap: wrap !important;
}

.fc-cs-btn {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 7px !important;
  padding: 9px 18px !important;
  border-radius: var(--radius-sm, 6px) !important;
  font-family: var(--font-sans) !important;
  font-size: var(--text-sm, 0.875rem) !important;
  font-weight: 600 !important;
  text-decoration: none !important;
  cursor: pointer !important;
  transition: all var(--transition-fast) !important;
  flex: 1 1 180px !important;
  box-sizing: border-box !important;
}

.fc-cs-btn-primary {
  background: var(--accent) !important;
  color: var(--text-inverse) !important;
  border: 1px solid var(--accent) !important;
}

.fc-cs-btn-primary:hover {
  filter: brightness(1.08) !important;
  transform: translateY(-1px) !important;
  box-shadow: 0 4px 14px rgba(40, 85, 130, 0.25) !important;
}

[data-theme="dark"] .fc-cs-btn-primary:hover {
  box-shadow: 0 4px 16px rgba(123, 167, 217, 0.35) !important;
}

.fc-cs-btn-secondary {
  background: transparent !important;
  color: var(--text-secondary) !important;
  border: 1px solid var(--border-default) !important;
}

.fc-cs-btn-secondary:hover {
  color: var(--text-primary) !important;
  border-color: var(--border-strong) !important;
  background: var(--bg-surface-subtle) !important;
}

/* Footer Metadata Note */
.fc-coming-soon-footer {
  padding: 11px 24px 13px !important;
  border-top: 1px solid var(--border-subtle) !important;
  background: var(--bg-surface) !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 6px !important;
  font-family: var(--font-mono) !important;
  font-size: var(--text-3xs, 11px) !important;
  color: var(--text-tertiary) !important;
  letter-spacing: 0.02em !important;
}

.fc-coming-soon-footer svg {
  color: var(--text-quaternary) !important;
}

@media (max-width: 600px) {
  .fc-coming-soon-header {
    padding: 18px 18px 14px !important;
  }
  .fc-coming-soon-body {
    padding: 16px 18px !important;
  }
  .fc-coming-soon-actions {
    padding: 0 18px 16px !important;
  }
  .fc-cs-btn {
    flex: 1 1 100% !important;
  }
  .fc-coming-soon-footer {
    padding: 10px 18px 12px !important;
    text-align: center !important;
  }
}

/* ==========================================================================
   Flashcards Hub Page Layout (Faithful to MARKS Reference UI)
   ========================================================================== */

.flashcards-standalone-page {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.25rem 2rem 4rem;
  box-sizing: border-box;
  width: 100%;
}

@media (max-width: 860px) {
  .flashcards-standalone-page {
    padding: 1rem 1.25rem 3.5rem;
  }
}

@media (max-width: 640px) {
  .flashcards-standalone-page {
    padding: 0.75rem 1rem 2.5rem;
  }
}

@media (max-width: 480px) {
  .flashcards-standalone-page {
    padding: 0.65rem 12px 2rem;
  }
}

.flashcards-standalone-page .fc-page-hero,
.flashcards-standalone-page .browse-back-nav {
  display: none !important;
}

.flashcards-page-container {
  width: 100%;
  box-sizing: border-box;
}

.fc-hub-layout {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 32px;
  min-height: 70vh;
  margin-top: 0.5rem;
  align-items: start;
}

/* Left Sidebar Subject Ladder (Clean & Minimal) */
.fc-hub-sidebar {
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: sticky;
  top: 84px;
  height: fit-content;
}

.fc-hub-sidebar-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

/* Mobile Subject Dropdown Menu: Hidden on desktop */
.fc-hub-mobile-select-wrap {
  display: none;
}

.fc-hub-nav-item {
  display: flex;
  align-items: center;
  padding: 9px 14px;
  border-radius: var(--radius-sm, 6px);
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  width: 100%;
  position: relative;
  text-decoration: none;
}

.fc-hub-nav-item:hover:not(.active) {
  background: var(--bg-surface-subtle);
  border-color: var(--border-subtle);
  color: var(--text-primary);
}

/* Active State: Refined StudyDump surface with colored left accent indicator */
.fc-hub-nav-item.active {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  border-left: 3.5px solid var(--sub-color, var(--accent));
  color: var(--text-primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.fc-hub-nav-content {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

/* Restrained, tinted icon container */
.fc-hub-icon-box {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  background: rgba(var(--sub-rgb, 123, 167, 217), 0.12);
  color: var(--sub-color, var(--accent));
  border: 1px solid rgba(var(--sub-rgb, 123, 167, 217), 0.22);
  transition: all var(--transition-fast);
}

.fc-hub-nav-item:hover .fc-hub-icon-box,
.fc-hub-nav-item.active .fc-hub-icon-box {
  background: rgba(var(--sub-rgb, 123, 167, 217), 0.2);
  border-color: rgba(var(--sub-rgb, 123, 167, 217), 0.4);
}

.fc-hub-nav-title {
  font-family: var(--font-editorial);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color var(--transition-fast);
}

.fc-hub-nav-item:hover .fc-hub-nav-title,
.fc-hub-nav-item.active .fc-hub-nav-title {
  color: var(--text-primary);
}

/* Right Main Content Area */
.fc-hub-main {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

/* Top Header Bar */
.fc-hub-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 14px;
  gap: 16px;
}

.fc-hub-subject-heading {
  font-family: var(--font-editorial);
  font-size: clamp(1.4rem, 2.5vw, 1.95rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.2;
}

.fc-hub-top-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.fc-hub-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 14px;
  border-radius: var(--radius-sm, 6px);
  font-size: 12.5px;
  font-weight: 600;
  font-family: var(--font-editorial);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid var(--border-default);
  background: var(--bg-surface);
  color: var(--text-primary);
  text-decoration: none;
}

.fc-hub-action-btn:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--border-strong);
  transform: translateY(-1px);
}

.fc-hub-action-btn.primary {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(40, 85, 130, 0.25);
}

[data-theme="dark"] .fc-hub-action-btn.primary {
  background: var(--accent);
  color: #0d0f12;
  box-shadow: 0 2px 10px rgba(123, 167, 217, 0.3);
}

.fc-hub-action-btn.primary:hover {
  filter: brightness(1.08);
}

.fc-hub-search-label {
  font-size: 12.5px;
}

.fc-hub-kbd {
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 1px 5px;
  border-radius: var(--radius-xs);
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-default);
  color: var(--text-tertiary);
}

/* Filter Bar */
.fc-hub-filter-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.fc-hub-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px;
  border-radius: var(--radius-sm, 6px);
  font-size: 12.5px;
  font-weight: 500;
  font-family: var(--font-editorial);
  border: 1px solid var(--border-default);
  background: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.fc-hub-chip:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
  background: var(--bg-surface-elevated);
}

.fc-hub-chip.active {
  background: var(--bg-surface-elevated);
  color: var(--text-primary);
  border-color: var(--accent);
  font-weight: 600;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.12);
}

.fc-hub-chip-count {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 999px;
  background: var(--bg-surface-subtle);
  color: var(--text-tertiary);
  border: 1px solid var(--border-subtle);
}

.fc-hub-chip.active .fc-hub-chip-count {
  background: var(--accent-subtle);
  border-color: var(--accent-border);
  color: var(--accent);
  font-weight: 600;
}

/* Decks Grid: 4 columns across */
.fc-deck-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px 22px;
}

@media (max-width: 1280px) {
  .fc-deck-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 960px) {
  .fc-deck-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 580px) {
  .fc-deck-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Stacked Deck Item */
.fc-deck-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  cursor: pointer;
  text-decoration: none;
  outline: none;
  background: transparent;
  border: none;
  padding: 0 12px 10px 0;
  box-sizing: border-box;
  text-align: left;
  -webkit-tap-highlight-color: transparent;
  width: 100%;
}

.fc-deck-stack {
  position: relative;
  width: 100%;
  height: 285px; /* Tall portrait deck proportion */
  border-radius: 20px;
}

/* Stack Layers (Behind the top card) */
.fc-stack-layer {
  position: absolute;
  inset: 0;
  border-radius: 20px;
  border: 1.5px solid var(--deck-color, var(--accent, #7ba7d9));
  background: #0f1219;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
  pointer-events: none;
}

.fc-layer-back {
  transform: translate(10px, 8px);
  opacity: 0.25;
  z-index: 1;
}

.fc-layer-mid {
  transform: translate(5px, 4px);
  opacity: 0.55;
  z-index: 2;
}

/* Top Deck Card */
.fc-deck-card {
  position: absolute;
  inset: 0;
  z-index: 3;
  border-radius: 20px;
  border: 1.5px solid var(--deck-color, var(--accent, #7ba7d9));
  background: #141720;
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease, border-color 0.3s ease;
}

/* Desktop Hover Fan-out Animation (Pointer Devices Only) */
@media (hover: hover) and (pointer: fine) {
  .fc-deck-item:hover .fc-deck-card {
    transform: translate(-3px, -3px);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5), 0 0 24px rgba(var(--deck-glow, 56, 189, 248), 0.25);
  }

  .fc-deck-item:hover .fc-layer-mid {
    transform: translate(8px, 7px);
    opacity: 0.75;
  }

  .fc-deck-item:hover .fc-layer-back {
    transform: translate(15px, 13px);
    opacity: 0.4;
  }
}

/* Tactile Mobile / Touch Feedback */
.fc-deck-item:active .fc-deck-card {
  transform: scale(0.985);
  transition: transform 0.1s ease;
}

.fc-deck-card-top {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  z-index: 2;
}

.fc-deck-pill {
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(var(--deck-glow, 123, 167, 217), 0.12);
  color: var(--deck-color, var(--accent, #7ba7d9));
  border: 1px solid rgba(var(--deck-glow, 123, 167, 217), 0.32);
}

.fc-deck-card-body {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin: 12px 0 auto;
  z-index: 2;
}

.fc-deck-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.35;
  color: #ffffff;
  margin: 0;
}

.fc-deck-topics-count {
  font-size: 12px;
  color: #9ca3af;
  font-weight: 500;
  margin-top: 4px;
}

.fc-deck-card-bottom {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  position: relative;
  z-index: 2;
  margin-top: 18px;
}

.fc-deck-cards-count {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  color: #9ca3af;
}

.fc-deck-watermark {
  position: absolute;
  right: -10px;
  bottom: -10px;
  width: 76px;
  height: 76px;
  color: var(--deck-color, var(--accent, #7ba7d9));
  opacity: 0.18;
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.fc-deck-watermark svg {
  width: 100%;
  height: 100%;
}

@media (hover: hover) and (pointer: fine) {
  .fc-deck-item:hover .fc-deck-watermark {
    opacity: 0.35;
    transform: scale(1.08);
  }
}

/* Caption line with subject name written below */
.fc-deck-caption {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding: 0 4px;
}

.fc-deck-caption-subject {
  font-size: 12.5px;
  font-weight: 600;
  color: #9ca3af;
}

/* ==========================================================================
   Responsive Flashcards Hub Layout (Tablet & Mobile)
   ========================================================================== */

/* Tablet Viewports (<= 860px) */
@media (max-width: 860px) {
  .fc-hub-layout {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .fc-hub-sidebar {
    position: sticky;
    top: 58px;
    z-index: 25;
    background: var(--bg-app);
    padding: 6px 0 8px;
    margin: -6px 0 0;
    border-bottom: 1px solid var(--border-subtle);
  }

  .fc-hub-sidebar-header,
  .fc-hub-sidebar-footer {
    display: none;
  }

  .fc-hub-sidebar-list {
    flex-direction: row;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    gap: 8px;
    padding: 2px 2px 4px;
    scroll-snap-type: x mandatory;
  }

  .fc-hub-sidebar-list::-webkit-scrollbar {
    display: none;
  }

  .fc-hub-nav-item {
    width: auto;
    flex: 1 1 0;
    min-width: 90px;
    padding: 8px 12px;
    justify-content: center;
    scroll-snap-align: start;
    -webkit-tap-highlight-color: transparent;
  }

  .fc-hub-nav-item.active {
    border-left: 1px solid var(--border-default);
    border-bottom: 3px solid var(--sub-color, var(--accent));
  }

  .fc-hub-top-bar {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding-bottom: 12px;
  }

  .fc-hub-subject-heading {
    font-size: clamp(1.25rem, 3.5vw, 1.7rem);
  }

  .fc-hub-top-actions {
    width: auto;
    flex-shrink: 0;
  }

  .fc-deck-stack {
    height: 255px;
  }

  .fc-deck-card {
    padding: 20px 18px;
  }

  .fc-deck-title {
    font-size: 1.1rem;
  }
}

/* Mobile Devices (<= 768px): Subject Dropdown & 2 Side-by-Side Smaller Cards */
@media (max-width: 768px) {
  /* 1. Subject selection is a dropdown menu on mobile devices only */
  .fc-hub-sidebar-list {
    display: none !important;
  }

  .fc-hub-sidebar {
    position: static;
    top: auto;
    border-bottom: none;
    padding: 0;
    margin: 0 0 2px 0;
    background: transparent;
    z-index: 5;
  }

  .fc-hub-mobile-select-wrap {
    display: block;
    width: 100%;
  }

  .fc-hub-select-inner {
    position: relative;
    display: flex;
    align-items: center;
    width: 100%;
    background: var(--bg-surface-elevated, #141720);
    border: 1.5px solid var(--sub-color, var(--accent, #7ba7d9));
    border-radius: var(--radius-md, 12px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25), 0 0 16px rgba(var(--sub-rgb, 123, 167, 217), 0.12);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    box-sizing: border-box;
  }

  .fc-hub-select-inner:focus-within {
    border-color: var(--sub-color, var(--accent));
    box-shadow: 0 0 0 3px rgba(var(--sub-rgb, 123, 167, 217), 0.25);
  }

  .fc-hub-select-icon {
    position: absolute;
    left: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: rgba(var(--sub-rgb, 123, 167, 217), 0.14);
    color: var(--sub-color, var(--accent, #7ba7d9));
    pointer-events: none;
    z-index: 2;
  }

  .fc-hub-select-icon svg {
    width: 15px;
    height: 15px;
  }

  .fc-hub-subject-select {
    width: 100%;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background: transparent;
    color: var(--text-primary, #ffffff);
    font-family: inherit;
    font-size: 13.5px;
    font-weight: 600;
    line-height: 1.4;
    padding: 11px 36px 11px 46px;
    border: none;
    outline: none;
    cursor: pointer;
    border-radius: var(--radius-md, 12px);
    box-sizing: border-box;
  }

  .fc-hub-subject-select option {
    background: #141720;
    color: #f3f4f6;
    font-size: 14px;
    padding: 8px 12px;
  }

  [data-theme="light"] .fc-hub-select-inner {
    background: var(--bg-surface-elevated, #ffffff);
  }

  [data-theme="light"] .fc-hub-subject-select option {
    background: #ffffff;
    color: #111827;
  }

  .fc-hub-select-arrow {
    position: absolute;
    right: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary, #9ca3af);
    pointer-events: none;
  }

  .fc-hub-select-arrow svg {
    width: 16px;
    height: 16px;
  }

  /* 2. Smaller Decks: 2 side by side with properly adjusted element proportions */
  .fc-deck-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 14px 10px;
  }

  .fc-deck-item {
    padding: 0 6px 6px 0;
  }

  .fc-deck-stack {
    height: 180px;
    border-radius: 15px;
  }

  .fc-stack-layer {
    border-radius: 15px;
  }

  .fc-layer-back {
    transform: translate(5px, 4px);
  }

  .fc-layer-mid {
    transform: translate(2.5px, 2px);
  }

  .fc-deck-card {
    border-radius: 15px;
    padding: 12px 11px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
  }

  .fc-deck-card-top {
    min-height: 18px;
  }

  .fc-deck-pill {
    font-size: 9.5px;
    padding: 2px 7px;
    letter-spacing: 0.02em;
    border-radius: 999px;
  }

  .fc-deck-card-body {
    margin: 6px 0 auto;
    gap: 2px;
  }

  .fc-deck-title {
    font-size: 0.88rem;
    line-height: 1.24;
    font-weight: 700;
    word-break: break-word;
    overflow-wrap: anywhere;
  }

  .fc-deck-topics-count {
    font-size: 10.5px;
    margin-top: 2px;
  }

  .fc-deck-card-bottom {
    margin-top: 6px;
  }

  .fc-deck-cards-count {
    font-size: 11px;
    gap: 4px;
  }

  .fc-deck-cards-count svg {
    width: 11px;
    height: 11px;
  }

  .fc-deck-watermark {
    width: 46px;
    height: 46px;
    right: -4px;
    bottom: -4px;
    opacity: 0.16;
  }
}

/* Mobile Devices (<= 640px) */
@media (max-width: 640px) {
  .fc-hub-layout {
    gap: 12px;
    margin-top: 0.25rem;
  }

  .fc-hub-top-bar {
    padding-bottom: 8px;
    gap: 10px;
  }

  .fc-hub-subject-heading {
    font-size: 1.25rem;
  }

  .fc-hub-filter-bar {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding: 2px 2px 4px;
    gap: 6px;
  }

  .fc-hub-filter-bar::-webkit-scrollbar {
    display: none;
  }

  .fc-hub-chip {
    flex-shrink: 0;
    padding: 6px 12px;
    font-size: 12px;
    min-height: 32px;
    -webkit-tap-highlight-color: transparent;
  }

  .fc-hub-chip-count {
    font-size: 10.5px;
    padding: 1px 5px;
  }

  .fc-hub-action-btn {
    padding: 6px 10px;
    font-size: 12px;
    gap: 5px;
  }

  .fc-hub-kbd {
    display: none !important;
  }
}

/* Two-Column Compact Decks on Phones (<= 580px) */
@media (max-width: 580px) {
  .fc-deck-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 12px 9px;
  }

  .fc-deck-item {
    padding: 0 5px 5px 0;
  }

  .fc-deck-stack {
    height: 168px;
    border-radius: 14px;
  }

  .fc-stack-layer {
    border-radius: 14px;
  }

  .fc-layer-back {
    transform: translate(4.5px, 3.5px);
  }

  .fc-layer-mid {
    transform: translate(2px, 1.5px);
  }

  .fc-deck-card {
    border-radius: 14px;
    padding: 11px 9px;
  }

  .fc-deck-pill {
    font-size: 8.5px;
    padding: 1.5px 6px;
  }

  .fc-deck-card-body {
    margin: 5px 0 auto;
  }

  .fc-deck-title {
    font-size: 0.82rem;
    line-height: 1.22;
  }

  .fc-deck-topics-count {
    font-size: 10px;
    margin-top: 1.5px;
  }

  .fc-deck-card-bottom {
    margin-top: 6px;
  }

  .fc-deck-cards-count {
    font-size: 10.5px;
    gap: 3.5px;
  }

  .fc-deck-cards-count svg {
    width: 10.5px;
    height: 10.5px;
  }

  .fc-deck-watermark {
    width: 40px;
    height: 40px;
    right: -4px;
    bottom: -4px;
    opacity: 0.15;
  }
}

/* Compact Mobile (<= 480px) */
@media (max-width: 480px) {
  .fc-hub-subject-heading {
    font-size: 1.2rem;
  }
}

/* Small Screens (<= 380px) */
@media (max-width: 380px) {
  .fc-deck-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 10px 7px;
  }

  .fc-deck-item {
    padding: 0 4px 4px 0;
  }

  .fc-deck-stack {
    height: 158px;
    border-radius: 12px;
  }

  .fc-stack-layer {
    border-radius: 12px;
  }

  .fc-layer-back {
    transform: translate(4px, 3px);
  }

  .fc-layer-mid {
    transform: translate(2px, 1.5px);
  }

  .fc-deck-card {
    border-radius: 12px;
    padding: 9px 8px;
  }

  .fc-deck-pill {
    font-size: 8px;
    padding: 1px 5px;
  }

  .fc-deck-card-body {
    margin: 4px 0 auto;
  }

  .fc-deck-title {
    font-size: 0.76rem;
    line-height: 1.18;
  }

  .fc-deck-topics-count {
    font-size: 9.5px;
    margin-top: 1px;
  }

  .fc-deck-card-bottom {
    margin-top: 4px;
  }

  .fc-deck-cards-count {
    font-size: 10px;
    gap: 3px;
  }

  .fc-deck-cards-count svg {
    width: 10px;
    height: 10px;
  }

  .fc-deck-watermark {
    width: 34px;
    height: 34px;
    right: -3px;
    bottom: -3px;
    opacity: 0.14;
  }

  .fc-hub-action-btn {
    padding: 5px 8px;
    font-size: 11.5px;
  }
}


/* ==========================================================================
   Full-Screen Flashcards Shell Layout
   ========================================================================== */

.fc-fullscreen-root {
  display: flex;
  flex-direction: column;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  background: var(--bg-app);
  color: var(--text-primary);
  overflow: hidden;
  position: relative;
  user-select: none;
}

/* 1. Top Story Segmented Progress Bar (Instagram / MARKS Stories aesthetic) */
.fc-story-progress-bar {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 10px 20px 4px;
  width: 100%;
  box-sizing: border-box;
  background: var(--bg-surface);
  z-index: 10;
}

.fc-story-seg {
  flex: 1;
  height: 4px;
  border-radius: 999px;
  background: var(--border-default);
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.fc-story-seg:hover {
  transform: scaleY(1.6);
  background: var(--text-tertiary);
}

.fc-story-seg.seen {
  background: var(--text-quaternary);
}

.fc-story-seg.active {
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent);
  transform: scaleY(1.3);
}

.fc-story-seg.mastered {
  background: #10b981;
}

.fc-story-seg.review {
  background: #f59e0b;
}

/* 2. Full-Screen Header */
.fc-fs-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  background: #0c0f14;
  min-height: 52px;
  gap: 16px;
  z-index: 9;
  box-sizing: border-box;
}

.fc-fs-header-left {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.fc-counter-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: #94a3b8;
  background: #161b24;
  border: 1px solid #2e3646;
  padding: 4px 11px;
  border-radius: 999px;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.fc-counter-badge svg {
  color: #94a3b8;
}

.fc-fs-header-title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  font-weight: 600;
  color: #94a3b8;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.fc-fs-subj-name {
  color: #f1f5f9;
  font-weight: 700;
}

.fc-fs-dot {
  color: #475569;
}

.fc-fs-topic-name {
  color: #94a3b8;
  overflow: hidden;
  text-overflow: ellipsis;
}

.fc-fs-header-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.fc-fs-header-btn {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid #2e3646;
  background: #161b24;
  color: #94a3b8;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.fc-fs-header-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #f1f5f9;
  border-color: #475569;
  transform: scale(1.05);
}

.fc-fs-bookmark-btn.bookmarked {
  background: rgba(123, 167, 217, 0.16);
  border-color: var(--accent, #7ba7d9);
  color: var(--accent, #7ba7d9);
}

.fc-fs-bookmark-btn.bookmarked:hover {
  background: var(--accent, #7ba7d9);
  color: #0b0f17;
  border-color: var(--accent, #7ba7d9);
}

.fc-fs-close-btn {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid #2e3646;
  background: #161b24;
  color: #94a3b8;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.fc-fs-close-btn:hover {
  background: #ef4444;
  color: #ffffff;
  border-color: #ef4444;
  transform: rotate(90deg);
}

/* 3. Center Main Hero Stage */
.fc-fs-main-stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 14px 20px;
  position: relative;
  overflow: hidden;
  min-height: 0;
  width: 100%;
  box-sizing: border-box;
}

.fc-fs-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  flex: 1 1 0;
  min-height: 0;
  max-width: 900px;
  gap: 28px;
  position: relative;
}

/* Floating Circular Side Navigation Chevrons */
.fc-fs-side-arrow {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #161b24;
  border: 1px solid #2e3646;
  color: #94a3b8;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  flex-shrink: 0;
  z-index: 5;
}

.fc-fs-side-arrow:hover:not(:disabled) {
  background: #1e2430;
  color: #ffffff;
  border-color: var(--accent, #7ba7d9);
  transform: scale(1.1);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
}

.fc-fs-side-arrow:disabled {
  opacity: 0.2;
  cursor: not-allowed;
}

/* 3D Perspective Card Stage */
.fc-fs-card-stage,
.flashcard-stage {
  perspective: 1200px;
  -webkit-perspective: 1200px;
  width: 100%;
  max-width: 540px;
  height: 100%;
  max-height: min(840px, calc(100vh - 160px));
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 3D Flipping Card Container */
.flashcard-card {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  -webkit-transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
  cursor: pointer;
  outline: none;
  border-radius: 24px;
}

.flashcard-card.flipped {
  transform: rotateY(180deg);
}

.flashcard-card:focus-visible {
  box-shadow: 0 0 0 3px var(--accent, #7ba7d9);
}

/* Card Faces: Elevated Premium Study Sheet */
.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 24px;
  border: 1px solid rgba(226, 232, 240, 0.95);
  background: #ffffff !important;
  background-image: 
    radial-gradient(ellipse at 85% 0%, rgba(123, 167, 217, 0.09) 0%, transparent 60%),
    linear-gradient(180deg, #ffffff 0%, #fbfcfe 65%, #f7f9fd 100%) !important;
  color: #0f172a !important;
  box-shadow: 
    0 24px 56px -12px rgba(0, 0, 0, 0.6),
    0 0 0 1px rgba(255, 255, 255, 0.12),
    0 4px 12px rgba(0, 0, 0, 0.08);
  display: flex;
  flex-direction: column;
  padding: 26px 28px;
  box-sizing: border-box;
  overflow: hidden;
  text-align: left;
}

/* Elegant Subject Accent Stripe at Top of Card */
.flashcard-face::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3.5px;
  background: linear-gradient(90deg, var(--card-accent, #7ba7d9) 0%, rgba(123, 167, 217, 0.45) 60%, transparent 100%);
  z-index: 3;
}

/* Ambient SVG Watermark for Depth without Clutter */
.fc-card-watermark {
  position: absolute;
  right: -14px;
  bottom: -14px;
  width: 175px;
  height: 175px;
  opacity: 0.045;
  pointer-events: none;
  color: #0f172a;
  transform: rotate(-8deg);
  z-index: 0;
}

.fc-card-watermark svg {
  width: 100%;
  height: 100%;
}

/* Sheet Header */
.fc-sheet-header {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-bottom: 1px solid #f1f5f9;
  padding-bottom: 14px;
  position: relative;
  z-index: 1;
}

.fc-sheet-header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.fc-sheet-unit-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: #475569;
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
  padding: 3px 10px;
  border-radius: 999px;
  letter-spacing: 0.02em;
}

.fc-sheet-header-meta {
  display: flex;
  align-items: center;
  gap: 8px;
}

.fc-card-seq {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: #94a3b8;
  letter-spacing: 0.02em;
}

.fc-bookmarked-indicator {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #f59e0b;
}

.fc-sheet-title {
  font-family: var(--font-display, var(--font-sans));
  font-size: 1.35rem;
  font-weight: 700;
  color: #0f172a;
  margin: 0;
  line-height: 1.3;
  letter-spacing: -0.015em;
}

.fc-sheet-flip-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: #f8fafc;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  padding: 3px 8px;
  font-size: 11px;
  font-weight: 600;
  color: #334155;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.fc-sheet-flip-btn:hover {
  background: #e2e8f0;
  color: #0f172a;
}

/* Front Face Layout */
.flashcard-face.flashcard-front {
  justify-content: space-between;
  touch-action: pan-x;
}

.fc-sheet-front-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  z-index: 1;
  padding: 22px 0;
}

.fc-question-callout {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.fc-question-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: #64748b;
  background: rgba(100, 116, 139, 0.08);
  padding: 3px 8px;
  border-radius: 4px;
  width: fit-content;
}

.flashcard-front .fc-card-question {
  font-family: var(--font-display, var(--font-sans));
  font-size: clamp(1.3rem, 2.5vw, 1.62rem);
  font-weight: 700;
  color: #0f172a;
  line-height: 1.55;
  margin: 0;
  letter-spacing: -0.012em;
}

/* Quiet Ambient Card Footer */
.fc-sheet-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid #f1f5f9;
  position: relative;
  z-index: 1;
}

.fc-sheet-flip-hint {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  font-weight: 500;
  color: #94a3b8;
  letter-spacing: 0.01em;
}

.fc-sheet-flip-hint svg {
  color: #94a3b8;
}


/* Back Face Layout (Illustrated Study Sheet) */
.flashcard-face.flashcard-back {
  transform: rotateY(180deg);
}

.fc-sheet-content-scroll {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 10px 0 14px;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  overscroll-behavior: contain !important;
  touch-action: pan-y !important;
  -webkit-overflow-scrolling: touch !important;
}

.fc-sheet-content-scroll::-webkit-scrollbar {
  width: 5px;
}

.fc-sheet-content-scroll::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}

/* Distinct Modular Concept Cards (Clear Separation, Neutral Slate Surfaces, Zero Vibe-Coded Gimmicks) */
.fc-sheet-box {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.04);
  transition: border-color 0.15s ease, background-color 0.15s ease;
}

.fc-sheet-box:hover {
  background: #ffffff;
  border-color: #cbd5e1;
}

.fc-sheet-box-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display, var(--font-sans));
  font-size: 12px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #0f172a;
  background: transparent !important;
  padding: 0 !important;
  border: none !important;
  border-radius: 0 !important;
  margin-bottom: 2px;
}

.fc-sheet-box-badge svg {
  width: 14px;
  height: 14px;
  box-sizing: content-box;
  padding: 4px;
  border-radius: 6px;
  flex-shrink: 0;
}

.fc-sheet-box-content {
  font-size: 13.5px;
  line-height: 1.62;
  color: #334155;
}

.fc-sheet-box-content p {
  margin: 0 0 6px;
}

.fc-sheet-box-content p:last-child {
  margin-bottom: 0;
}

.fc-sheet-box-content code.fc-inline-code {
  font-family: var(--font-mono);
  font-size: 12px;
  background: rgba(15, 23, 42, 0.06);
  color: #0f172a;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid rgba(15, 23, 42, 0.08);
}

.fc-sheet-box-content pre.fc-code-block {
  margin: 8px 0;
  padding: 10px 12px;
  background: #0f172a;
  color: #f8fafc;
  border-radius: 8px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
}

/* Section Specific Styling Hooks */
.fc-big-idea,
.fc-core-rule,
.fc-exam-cue {
  position: relative;
}

.fc-sheet-box-badge.blue svg {
  background: rgba(37, 99, 235, 0.09);
  color: #2563eb;
}

.fc-sheet-box-badge.green svg {
  background: rgba(5, 150, 105, 0.09);
  color: #059669;
}

.fc-sheet-box-badge.purple svg {
  background: rgba(217, 119, 6, 0.09);
  color: #d97706;
}

/* 4. Pinned Bottom Evaluation Toolbar */
.fc-fs-bottom-bar {
  position: relative;
  width: 100%;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: #0c0f14;
  padding: 12px 24px;
  box-sizing: border-box;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  min-height: 70px;
}

.fc-fs-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  max-width: 680px;
  width: 100%;
}

.fc-fs-action-btn {
  flex: 1;
  max-width: 200px;
  height: 46px;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  border: 1.5px solid transparent;
}

.fc-fs-btn-review {
  background: rgba(239, 68, 68, 0.08);
  color: #f87171;
  border-color: rgba(239, 68, 68, 0.35);
}

.fc-fs-btn-review:hover {
  background: rgba(239, 68, 68, 0.2);
  border-color: #ef4444;
  color: #ffffff;
  transform: translateY(-1px);
}

.fc-fs-btn-review.active {
  background: rgba(239, 68, 68, 0.24);
  border-color: #ef4444;
  color: #ffffff;
  box-shadow: 0 0 14px rgba(239, 68, 68, 0.28);
}

.fc-fs-btn-flip {
  background: rgba(255, 255, 255, 0.06);
  color: #e2e8f0;
  border-color: rgba(255, 255, 255, 0.15);
}

.fc-fs-btn-flip:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  transform: translateY(-1px);
}

.fc-fs-btn-memorize {
  background: rgba(34, 197, 94, 0.08);
  color: #4ade80;
  border-color: rgba(34, 197, 94, 0.35);
}

.fc-fs-btn-memorize:hover {
  background: rgba(34, 197, 94, 0.2);
  border-color: #22c55e;
  color: #ffffff;
  transform: translateY(-1px);
}

.fc-fs-btn-memorize.active {
  background: rgba(34, 197, 94, 0.24);
  border-color: #22c55e;
  color: #ffffff;
  box-shadow: 0 0 14px rgba(34, 197, 94, 0.28);
}

.fc-fs-icon-btn {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.06);
  color: #94a3b8;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.fc-fs-icon-btn:hover {
  border-color: var(--accent, #7ba7d9);
  color: #ffffff;
  background: rgba(255, 255, 255, 0.12);
}

.fc-fs-icon-btn.bookmarked {
  background: var(--accent-subtle);
  border-color: var(--accent);
  color: var(--accent);
}

/* 5. Completion View */
.fc-completion-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 36px 24px;
  max-width: 500px;
  margin: auto;
}

.fc-completion-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.fc-completion-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 0 0 6px;
}

.fc-completion-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0 0 24px;
}

.fc-completion-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  width: 100%;
  margin-bottom: 28px;
}

.fc-stat-card {
  display: flex;
  flex-direction: column;
  padding: 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-default);
  background: var(--bg-surface-elevated);
}

.fc-stat-card.mastered {
  border-color: rgba(16, 185, 129, 0.3);
  background: rgba(16, 185, 129, 0.05);
}

.fc-stat-card.review {
  border-color: rgba(245, 158, 11, 0.3);
  background: rgba(245, 158, 11, 0.05);
}

.fc-stat-number {
  font-size: 24px;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-primary);
}

.fc-stat-card.mastered .fc-stat-number {
  color: #10b981;
}

.fc-stat-card.review .fc-stat-number {
  color: #f59e0b;
}

.fc-stat-label {
  font-size: 11px;
  color: var(--text-tertiary);
  margin-top: 4px;
}

.fc-completion-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  width: 100%;
}

.fc-primary-btn,
.fc-secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  border-radius: var(--radius-md);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.fc-primary-btn {
  background: var(--accent);
  color: #fff;
  border: none;
}

.fc-primary-btn:hover {
  opacity: 0.92;
}

.fc-secondary-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
}

.fc-secondary-btn:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

/* 6. All Cards Grid Mode */
.fc-fs-grid-container {
  width: 100%;
  height: 100%;
  overflow-y: auto;
  padding: 24px 20px;
  box-sizing: border-box;
  display: flex;
  justify-content: center;
  overscroll-behavior: contain !important;
  touch-action: pan-y !important;
  -webkit-overflow-scrolling: touch !important;
}

.fc-grid-view {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 16px;
  width: 100%;
  max-width: 1200px;
  height: fit-content;
}

.fc-grid-card {
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  padding: 18px;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.fc-grid-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

.fc-grid-card.mastered {
  border-left: 3px solid #10b981;
}

.fc-grid-card.review {
  border-left: 3px solid #f59e0b;
}

.fc-grid-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.fc-card-num {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--text-tertiary);
  margin-right: 6px;
}

.fc-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}

.fc-status-dot.green { background: #10b981; }
.fc-status-dot.yellow { background: #f59e0b; }
.fc-status-dot.gray { background: var(--border-default); }

.fc-grid-question {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 10px;
  line-height: 1.4;
}

.fc-grid-divider {
  height: 1px;
  background: var(--border-subtle);
  margin-bottom: 10px;
}

.fc-grid-answer-preview {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text-secondary);
}

.fc-grid-label {
  font-size: 11px;
  color: var(--text-primary);
}

.fc-grid-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  margin-top: 12px;
}

.fc-grid-rate-btn {
  font-size: 11px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-default);
  background: var(--bg-surface);
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.fc-grid-rate-btn.active[data-set-status="review"] {
  background: rgba(245, 158, 11, 0.15);
  color: #f59e0b;
  border-color: #f59e0b;
}

.fc-grid-rate-btn.active[data-set-status="mastered"] {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  border-color: #10b981;
}

.fc-empty-filter-state {
  padding: 40px 20px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 14px;
}

.fc-loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
  color: var(--text-tertiary);
  width: 100%;
  height: 100%;
}

.fc-spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border-default);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: fcSpin 0.8s linear infinite;
  margin-bottom: 12px;
}

@keyframes fcSpin {
  to { transform: rotate(360deg); }
}

/* 7. Responsive Mobile & Tablet Rules */
/* 7. Responsive Mobile & Tablet Rules */
@media (max-width: 768px) {
  .fc-story-progress-bar {
    padding: 6px 12px 2px;
    gap: 2.5px;
  }

  .fc-fs-header {
    padding: 8px 14px;
    gap: 8px;
    min-height: 48px;
  }

  .fc-fs-header-center {
    display: none;
  }

  .fc-fs-main-stage {
    padding: 10px 14px 6px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 0;
    overflow: hidden;
  }

  .fc-fs-stage {
    gap: 0;
    width: 100%;
    max-width: 100%;
    flex: 1 1 0;
    min-height: 0;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .fc-fs-side-arrow {
    display: none !important;
  }

  .fc-fs-card-stage,
  .flashcard-stage {
    width: 100%;
    max-width: min(480px, 100%);
    height: 100%;
    min-height: 0;
    max-height: none;
    display: flex;
    align-items: center;
    justify-content: center;
    perspective: 1200px;
    -webkit-perspective: 1200px;
    box-sizing: border-box;
  }

  .flashcard-card {
    width: 100%;
    height: 100%;
    min-height: 0;
    max-height: none;
    border-radius: 20px;
    position: relative;
  }

  .flashcard-face {
    padding: 18px 16px;
    border-radius: 20px;
  }

  .fc-sheet-header {
    padding-bottom: 10px;
    gap: 6px;
  }

  .fc-sheet-header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    width: 100%;
  }

  .fc-sheet-unit-badge {
    font-size: 10.5px;
    padding: 2.5px 8px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: calc(100% - 65px);
    flex-shrink: 1;
  }

  .fc-sheet-header-meta {
    flex-shrink: 0;
    white-space: nowrap;
    gap: 6px;
  }

  .fc-card-seq {
    font-size: 10.5px;
  }

  .fc-sheet-title {
    font-size: 1.18rem;
    line-height: 1.28;
    margin-top: 2px;
  }

  .fc-sheet-front-body {
    padding: 10px 0;
  }

  .fc-question-callout {
    gap: 8px;
  }

  .fc-question-chip {
    font-size: 9.5px;
    padding: 2.5px 7px;
  }

  .flashcard-front .fc-card-question,
  .fc-card-question {
    font-size: clamp(1.05rem, 3.8vw, 1.22rem);
    line-height: 1.45;
  }

  .fc-sheet-footer {
    padding-top: 10px;
  }

  .fc-sheet-flip-hint {
    font-size: 11px;
    gap: 5px;
  }

  .fc-fs-bottom-bar {
    padding: 8px 12px max(8px, var(--safe-bottom, 8px));
    min-height: 58px;
    box-sizing: border-box;
  }

  .fc-fs-bottom-inner {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    width: 100%;
    max-width: 480px;
  }

  .fc-fs-action-btn {
    width: 100%;
    max-width: none;
    height: 42px;
    font-size: 11.5px;
    padding: 0 4px;
    gap: 5px;
    border-radius: 999px;
  }

  .fc-fs-action-btn svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
  }

  .fc-fs-btn-label {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-size: 11px;
  }

  .fc-fs-kbd {
    display: none;
  }

  .fc-fs-icon-btn {
    width: 38px;
    height: 38px;
  }

  .fc-grid-view {
    grid-template-columns: 1fr;
  }

  .fc-sheet-box {
    padding: 10px 12px;
    border-radius: 10px;
    gap: 4px;
  }

  .fc-sheet-box-content {
    font-size: 12.5px;
    line-height: 1.55;
  }
}

@media (max-width: 480px) {
  .fc-fs-subj-name,
  .fc-fs-dot {
    display: none;
  }

  .fc-fs-header {
    padding: 6px 10px;
    min-height: 42px;
  }

  .fc-counter-badge {
    font-size: 10.5px;
    padding: 3px 7px;
  }

  .fc-fs-topic-name {
    font-size: 12px;
  }

  .fc-fs-header-btn,
  .fc-fs-close-btn {
    width: 32px;
    height: 32px;
  }

  .fc-fs-main-stage {
    padding: 6px 10px 4px;
  }

  .flashcard-card,
  .flashcard-face {
    border-radius: 16px;
  }

  .flashcard-face {
    padding: 15px 14px;
  }

  .fc-sheet-title {
    font-size: 1.1rem;
  }

  .flashcard-front .fc-card-question,
  .fc-card-question {
    font-size: 1.05rem;
    line-height: 1.4;
  }

  .fc-fs-bottom-bar {
    padding: 6px 8px max(8px, var(--safe-bottom, 8px));
    min-height: 54px;
  }

  .fc-fs-bottom-inner {
    gap: 6px;
  }

  .fc-fs-action-btn {
    height: 40px;
    font-size: 11px;
    padding: 0 3px;
    gap: 4px;
  }

  .fc-fs-action-btn svg {
    width: 13.5px;
    height: 13.5px;
  }

  .fc-fs-btn-label {
    font-size: 10.5px;
  }
}

@media (max-width: 360px) {
  .fc-fs-bottom-inner {
    gap: 4px;
  }

  .fc-fs-action-btn {
    height: 38px;
    font-size: 10px;
    gap: 3px;
    padding: 0 2px;
  }

  .fc-fs-action-btn svg {
    width: 13px;
    height: 13px;
  }

  .fc-fs-btn-label {
    font-size: 10px;
  }
}

/* Flashcard Enhancements: Mobile Swipe Hint */

.fc-mobile-swipe-hint {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-top: 10px;
  color: var(--text-tertiary);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.02em;
  user-select: none;
}

@media (max-width: 768px) {
  .fc-mobile-swipe-hint {
    display: flex;
  }
}

/* ==========================================================================
   Subject Page: Active Recall Flashcard Section Banner
   ========================================================================== */
.subject-flashcards-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 1.5rem 1.75rem;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.04) 0%, rgba(255, 255, 255, 0.01) 100%);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg, 14px);
  margin-top: 0.85rem;
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.subject-flashcards-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 12% 20%, rgba(123, 167, 217, 0.08) 0%, transparent 60%);
  pointer-events: none;
}

.subject-flashcards-card:hover {
  border-color: var(--border-default);
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.3);
}

.subject-fc-content {
  flex: 1;
  min-width: 0;
  position: relative;
  z-index: 1;
}

.subject-fc-badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.65rem;
}

.subject-fc-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  padding: 0.2rem 0.55rem;
  border-radius: 9999px;
  background: rgba(123, 167, 217, 0.12);
  color: var(--accent);
  border: 1px solid rgba(123, 167, 217, 0.25);
}

.subject-fc-badge.unit-badge {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  border-color: var(--border-subtle);
}

.subject-fc-badge.mastered-badge {
  background: rgba(34, 197, 94, 0.12);
  color: #4ade80;
  border-color: rgba(34, 197, 94, 0.3);
}

.subject-fc-badge.review-badge {
  background: rgba(234, 179, 8, 0.12);
  color: #facc15;
  border-color: rgba(234, 179, 8, 0.3);
}

.subject-fc-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 0.35rem 0;
}

.subject-fc-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0 0 1.15rem 0;
  max-width: 580px;
}

.subject-fc-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.btn-fc-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 1.15rem;
  background: var(--accent);
  color: #0b101b;
  font-size: 0.825rem;
  font-weight: 600;
  border-radius: var(--radius-sm, 8px);
  text-decoration: none;
  transition: transform 0.15s ease, filter 0.2s ease, box-shadow 0.2s ease;
}

.btn-fc-primary:hover {
  transform: translateY(-1px);
  filter: brightness(1.08);
  box-shadow: 0 4px 14px rgba(123, 167, 217, 0.35);
}

.btn-fc-secondary {
  display: inline-flex;
  align-items: center;
  padding: 0.55rem 0.9rem;
  color: var(--text-secondary);
  font-size: 0.825rem;
  font-weight: 500;
  border-radius: var(--radius-sm, 8px);
  text-decoration: none;
  background: transparent;
  border: 1px solid var(--border-subtle);
  transition: color 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}

.btn-fc-secondary:hover {
  color: var(--text-primary);
  border-color: var(--border-default);
  background: rgba(255, 255, 255, 0.03);
}

.subject-fc-preview-visual {
  position: relative;
  width: 130px;
  height: 110px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 600px;
}

.subject-fc-preview-visual .mini-card {
  position: absolute;
  width: 108px;
  height: 76px;
  border-radius: 10px;
  border: 1px solid var(--border-default);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 8px;
  text-align: center;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.subject-fc-preview-visual .mini-card-bg {
  background: var(--bg-surface-elevated, #161b26);
  transform: rotate(8deg) translate(8px, 6px);
  opacity: 0.45;
  border-color: var(--border-subtle);
}

.subject-fc-preview-visual .mini-card-front {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.95), rgba(15, 23, 42, 0.95));
  transform: rotate(-3deg);
  z-index: 2;
  border-color: rgba(123, 167, 217, 0.35);
}

.subject-fc-preview-visual .mini-card-topic {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--accent);
  text-transform: uppercase;
}

.subject-fc-preview-visual .mini-card-text {
  font-size: 0.62rem;
  color: var(--text-secondary);
  margin: 3px 0;
  line-height: 1.2;
}

.subject-fc-preview-visual .mini-card-pill {
  font-size: 0.55rem;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 4px;
  background: rgba(123, 167, 217, 0.15);
  color: var(--accent);
}

@media (max-width: 640px) {
  .subject-flashcards-card {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.25rem;
  }
  .subject-fc-preview-visual {
    display: none;
  }
}




.pwa-update-toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 1050;
  max-width: 420px;
  transform: translateY(140%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s ease;
}

.pwa-update-toast.pwa-toast-visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.pwa-toast-inner {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.85rem 1.15rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.38), 0 0 0 1px rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.pwa-toast-icon-wrap {
  position: relative;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  border: 1px solid var(--accent-border);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.pwa-toast-pulse {
  position: absolute;
  top: -2px;
  right: -2px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 2px var(--bg-surface-elevated);
  animation: pwaPulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pwaPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.35); }
}

.pwa-toast-text {
  flex: 1;
  min-width: 0;
}

.pwa-toast-title {
  display: block;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
}

.pwa-toast-desc {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.35;
  margin-top: 2px;
}

.pwa-toast-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.pwa-toast-reload-btn {
  background: var(--accent);
  color: #ffffff;
  border: none;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.pwa-toast-reload-btn:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

.pwa-toast-reload-btn:active {
  transform: translateY(0);
}

.pwa-toast-reload-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.pwa-toast-dismiss-btn {
  background: transparent;
  color: var(--text-tertiary);
  border: 1px solid transparent;
  border-radius: var(--radius-xs);
  padding: 0.35rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.pwa-toast-dismiss-btn:hover {
  color: var(--text-primary);
  background: var(--bg-surface-subtle);
  border-color: var(--border-default);
}

@media (max-width: 640px) {
  .pwa-update-toast {
    left: 1rem;
    right: 1rem;
    bottom: 1rem;
    max-width: none;
  }

  .pwa-toast-inner {
    padding: 0.75rem 0.95rem;
    gap: 0.7rem;
  }
}

/* ==========================================================================
   Content Request & Student Material Upload System
   ========================================================================== */

.footer-request-banner {
  margin-bottom: var(--space-6);
  padding: 1.5rem 1.75rem;
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.45) 0%, rgba(15, 23, 42, 0.6) 100%);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  position: relative;
  overflow: hidden;
  transition: border-color var(--transition-normal);
}

.footer-request-banner:hover {
  border-color: var(--border-strong);
}

.request-banner-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.25rem;
  position: relative;
  z-index: 1;
}

.request-banner-header {
  flex: 1;
  min-width: 280px;
}

.request-banner-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--accent);
  background: var(--accent-subtle);
  border: 1px solid var(--accent-border);
  padding: 3px 11px 3px 9px;
  border-radius: 9999px;
  margin-bottom: 0.65rem;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
  transition: all var(--transition-fast);
}

.request-banner-badge svg {
  color: var(--accent);
  opacity: 0.92;
  flex-shrink: 0;
}


.request-banner-title {
  font-family: var(--font-sans);
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  margin: 0 0 0.35rem 0;
}

.request-banner-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin: 0;
  max-width: 680px;
}

.request-banner-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.65rem 1.25rem;
  background: var(--accent);
  color: #ffffff;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.request-banner-btn:hover {
  filter: brightness(1.12);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
}

.request-banner-btn:active {
  transform: translateY(0);
}

@media (max-width: 768px) {
  .footer-request-banner {
    padding: 1.25rem 1.15rem;
  }
  .request-banner-header {
    min-width: 0;
    width: 100%;
  }
  .request-banner-btn {
    width: 100%;
  }
  .request-banner-title {
    font-size: 1rem;
    overflow-wrap: break-word;
    word-break: break-word;
  }
  .request-banner-desc {
    overflow-wrap: break-word;
    word-break: break-word;
  }
  .request-dialog-panel {
    padding: 1.25rem 1rem;
    max-height: 92vh;
  }
  .form-actions {
    flex-direction: column-reverse;
    gap: 0.5rem;
  }
  .btn-cancel,
  .btn-submit {
    width: 100%;
    justify-content: center;
    min-height: 42px;
  }
}

/* Modal Dialog */
.request-dialog {
  padding: 0;
  border: none;
  background: transparent;
  max-width: 640px;
  width: 92vw;
  margin: auto;
  border-radius: var(--radius-lg);
  color: var(--text-primary);
}

.request-dialog::backdrop {
  background: rgba(4, 7, 14, 0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.request-dialog-panel {
  background: var(--bg-surface-elevated, #0f172a);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.05);
  padding: 1.5rem 1.75rem;
  max-height: 90vh;
  overflow-y: auto;
}

.request-dialog-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 1.25rem;
}

.request-dialog-title-group {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
}

.request-dialog-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  border: 1px solid var(--accent-border);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.request-dialog-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.3;
}

.request-dialog-subtitle {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin: 3px 0 0 0;
}

.request-dialog-close {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-tertiary);
  border-radius: var(--radius-xs);
  padding: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.request-dialog-close:hover {
  color: var(--text-primary);
  background: var(--bg-surface-subtle);
  border-color: var(--border-default);
}

/* Form Styles */
.request-form {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
}

.request-type-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.35rem;
}

.type-chip {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  user-select: none;
}

.type-chip input[type="radio"] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.type-chip:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
  background: var(--bg-surface-subtle);
}

.type-chip.active {
  background: var(--accent-subtle);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-row {
  display: flex;
  gap: 0.85rem;
}

@media (max-width: 600px) {
  .form-row {
    flex-direction: column;
  }
}

.flex-1 {
  flex: 1;
}

.form-label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.form-label-hint {
  font-size: 0.72rem;
  font-weight: normal;
  color: var(--text-tertiary);
}

.required-star {
  color: var(--accent, #3b82f6);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.6rem 0.85rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xs);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.85rem;
  transition: border-color var(--transition-fast);
  box-sizing: border-box;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-subtle);
}

.form-textarea {
  resize: vertical;
  min-height: 80px;
  line-height: 1.45;
}

/* Dropzone */
.dropzone {
  border: 2px dashed var(--border-default);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1rem;
  background: rgba(15, 23, 42, 0.4);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.dropzone:hover,
.dropzone.drag-over {
  border-color: var(--accent);
  background: var(--accent-subtle);
}

.dropzone:focus-visible {
  outline: 2px solid var(--accent);
}

.file-input-hidden {
  display: none;
}

.dropzone-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-secondary);
}

.dropzone-empty svg {
  color: var(--text-tertiary);
  margin-bottom: 2px;
}

.dropzone-text {
  font-size: 0.85rem;
}

.dropzone-action {
  color: var(--accent);
  font-weight: 600;
  text-decoration: underline;
}

.dropzone-formats {
  font-size: 0.72rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.dropzone-file-preview {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xs);
}

.file-preview-info {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-width: 0;
  text-align: left;
}

.file-preview-icon {
  width: 18px;
  height: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.file-preview-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.file-preview-name {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 320px;
}

.file-preview-size {
  font-size: 0.7rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.file-preview-remove {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.file-preview-remove:hover {
  color: #ef4444;
  background: rgba(239, 68, 68, 0.1);
}

/* Alert */
.form-alert {
  padding: 0.75rem 1rem;
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.35);
  border-radius: var(--radius-xs);
  color: #fca5a5;
  font-size: 0.82rem;
  line-height: 1.4;
}

.request-submit-note {
  margin: 0.75rem 0 0;
  color: var(--text-tertiary);
  font-size: var(--text-xs);
  line-height: 1.45;
}

/* Actions */
.form-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-top: 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
}

.btn-cancel {
  background: transparent;
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.55rem 1.1rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-cancel:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
  background: var(--bg-surface-subtle);
}

.btn-submit {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--accent);
  color: #ffffff;
  border: none;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.55rem 1.35rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-submit:hover {
  filter: brightness(1.12);
}

.btn-submit.loading .btn-text {
  opacity: 0.5;
}

.btn-spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #ffffff;
  animation: spin 0.8s linear infinite;
  display: inline-block;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Success View */
.request-success-view {
  text-align: center;
  padding: 1.75rem 1rem 1rem;
}

.success-icon-wrapper {
  width: 64px;
  height: 64px;
  margin: 0 auto 1.25rem;
  border-radius: 50%;
  background: rgba(16, 185, 129, 0.12);
  border: 2px solid #10b981;
  color: #10b981;
  display: flex;
  align-items: center;
  justify-content: center;
}

.success-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 0.5rem 0;
}

.success-message {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  max-width: 480px;
  margin: 0 auto 1.5rem;
}

.btn-done {
  background: var(--accent);
  color: #ffffff;
  border: none;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-done:hover {
  filter: brightness(1.12);
}

/* Search Modal Trigger Button */
.search-request-trigger-btn {
  background: transparent;
  border: none;
  color: var(--accent);
  font-weight: 600;
  text-decoration: underline;
  cursor: pointer;
  padding: 0;
  font-size: inherit;
}

/* ==========================================================================
   Website Opening Loading Screen Overlay
   ========================================================================== */

.site-page-loader {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 999999;
  background-color: var(--bg-app, #090d16);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 1;
  visibility: visible;
  transition: opacity 0.45s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.45s ease;
  pointer-events: all;
}

.flashcards-dialog .site-page-loader {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 999999;
}

.site-page-loader.is-dismissed {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.site-loader-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.site-loader-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
}

.site-loader-title {
  font-family: var(--font-editorial, "Playfair Display", Georgia, serif);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-primary, #f8fafc);
  letter-spacing: -0.02em;
  animation: loader-pulse 1.4s ease-in-out infinite alternate;
}

.site-loader-bar {
  width: 120px;
  height: 3px;
  background: var(--bg-surface-subtle, rgba(255, 255, 255, 0.08));
  border-radius: var(--radius-pill, 9999px);
  overflow: hidden;
  position: relative;
}

.site-loader-bar-fill {
  display: block;
  width: 50%;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--accent, #10b981), transparent);
  border-radius: var(--radius-pill, 9999px);
  position: absolute;
  animation: loader-slide 1.4s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

@keyframes loader-slide {
  0% {
    left: -50%;
  }
  100% {
    left: 100%;
  }
}

@keyframes loader-pulse {
  0% {
    opacity: 0.85;
    transform: scale(0.985);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

/* ==========================================================================
   Circular Motion Spinner (Resource Pages Loading)
   ========================================================================== */

.resource-loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  padding: 3rem 1.5rem;
  width: 100%;
  text-align: center;
  animation: fadeIn 0.25s ease;
}

.circular-motion-loader {
  position: relative;
  width: 52px;
  height: 52px;
  margin-bottom: 1.25rem;
}

.spinner-track {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  border: 3px solid rgba(16, 185, 129, 0.14);
}

.spinner-orbit-circle {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: var(--accent, #10b981);
  border-right-color: var(--accent, #10b981);
  animation: circular-spin 1.15s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

.spinner-orbit-dot {
  position: absolute;
  top: -4px;
  left: calc(50% - 4px);
  width: 8px;
  height: 8px;
  background-color: var(--accent, #10b981);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--accent, #10b981);
  animation: circular-orbit-dot 1.45s linear infinite;
  transform-origin: 4px 30px;
}

@keyframes circular-spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes circular-orbit-dot {
  to {
    transform: rotate(360deg);
  }
}

.resource-loading-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 0.25rem 0;
}

.resource-loading-sub {
  font-size: 0.82rem;
  color: var(--text-tertiary);
  margin: 0;
}


.search-request-trigger-btn:hover {
  color: #60a5fa;
}

.hidden {
  display: none !important;
}

/* ==========================================================================
   Resource Provenance & Curation Bookmark Ribbon + Slide-Over Drawer
   ========================================================================== */

.curation-ribbon-tab {
  position: fixed;
  top: 210px;
  right: 0;
  z-index: 45;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 14px 8px 22px;
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: var(--text-xs, 0.78rem);
  font-weight: 600;
  cursor: pointer;
  border: 1px solid var(--border-default);
  border-right: none;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%, 12px 50%);
  filter: drop-shadow(-3px 4px 10px rgba(0, 0, 0, 0.25));
  transition: all var(--transition-fast);
  transform: translate3d(0, 0, 0);
  will-change: transform;
  -webkit-tap-highlight-color: transparent;
}

.curation-ribbon-tab:hover,
.curation-ribbon-tab:active {
  transform: translate3d(-4px, 0, 0);
  border-color: var(--border-strong);
  color: var(--text-primary);
  background-color: var(--bg-surface-subtle);
}

.curation-ribbon-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  flex-shrink: 0;
}

.curation-ribbon-icon svg {
  width: 14px;
  height: 14px;
}

.curation-ribbon-label {
  white-space: nowrap;
}

@media (max-width: 640px) {
  .curation-ribbon-tab {
    top: auto;
    bottom: max(18px, var(--safe-bottom, 18px));
    right: 16px;
    clip-path: none;
    border-radius: 999px;
    padding: 7px 14px 7px 12px;
    font-size: 0.76rem;
    gap: 6px;
    background: var(--bg-surface-elevated, var(--bg-surface));
    border: 1px solid var(--border-default);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 90;
  }

  .curation-ribbon-tab:hover,
  .curation-ribbon-tab:active {
    transform: scale(0.96);
    background-color: var(--bg-surface-subtle);
    border-color: var(--border-strong);
  }

  .curation-ribbon-icon svg {
    width: 13px;
    height: 13px;
  }
}

/* Slide-Over Drawer Backdrop */
.curation-drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.curation-drawer-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

/* Slide-Over Drawer Pane (Desktop: Slide from Right | Mobile: Bottom Sheet) */
.curation-drawer-pane {
  position: fixed;
  top: 0;
  right: 0;
  width: min(390px, 92vw);
  height: 100vh;
  height: 100dvh;
  background: var(--bg-surface);
  border-left: 1px solid var(--border-default);
  z-index: 101;
  display: flex;
  flex-direction: column;
  box-shadow: -8px 0 28px rgba(0, 0, 0, 0.4);
  transform: translate3d(100%, 0, 0);
  transition: transform var(--transition-normal);
  overflow-y: auto;
  scrollbar-width: none;
}

.curation-drawer-pane::before {
  content: '';
  display: none;
  width: 38px;
  height: 4px;
  background: var(--border-strong, rgba(255, 255, 255, 0.25));
  border-radius: 999px;
  margin: 10px auto 2px;
  flex-shrink: 0;
  opacity: 0.7;
}

.curation-drawer-pane::-webkit-scrollbar {
  display: none;
}

.curation-drawer-pane.open {
  transform: translate3d(0, 0, 0);
}

@media (max-width: 640px) {
  .curation-drawer-pane {
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: auto;
    max-height: 86vh;
    max-height: 86dvh;
    border-left: none;
    border-top: 1px solid var(--border-default);
    border-radius: 16px 16px 0 0;
    transform: translate3d(0, 100%, 0);
    box-shadow: 0 -10px 36px rgba(0, 0, 0, 0.5);
    transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  }

  .curation-drawer-pane::before {
    display: block;
  }

  .curation-drawer-pane.open {
    transform: translate3d(0, 0, 0);
  }
}

.curation-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 1.25rem 0.9rem;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  flex-shrink: 0;
}

@media (max-width: 640px) {
  .curation-drawer-header {
    padding: 0.85rem 1.15rem 0.75rem;
  }
}

.curation-drawer-title-group {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.curation-drawer-badge {
  font-family: var(--font-mono);
  font-size: var(--text-3xs, 0.68rem);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
}

.curation-drawer-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.3;
}

@media (max-width: 640px) {
  .curation-drawer-title {
    font-size: 0.98rem;
  }
}

.curation-drawer-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  min-width: 32px;
  min-height: 32px;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.curation-drawer-close:hover,
.curation-drawer-close:active {
  background: var(--bg-surface-subtle);
  color: var(--text-primary);
  border-color: var(--border-default);
}

.curation-drawer-body {
  padding: 1.15rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (max-width: 640px) {
  .curation-drawer-body {
    padding: 1rem 1.15rem max(1.5rem, var(--safe-bottom, 20px));
    gap: 0.85rem;
  }
}

.curation-section {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--border-subtle);
}

.curation-section-title {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.curation-section-text {
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--text-secondary);
  margin: 0;
}

.curation-disclaimer-box {
  padding: 0.75rem 0.85rem;
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  line-height: 1.45;
  color: var(--text-tertiary);
}

.curation-disclaimer-box strong {
  color: var(--text-secondary);
  font-weight: 600;
}

/* ==========================================================================
   Student Profile & Personalization Modal
   ========================================================================== */

.studydump-profile-modal {
  position: fixed;
  inset: 0;
  z-index: 100000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(4, 7, 14, 0.92);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.12s ease, visibility 0.12s ease;
  padding: 20px 16px;
  box-sizing: border-box;
}

.studydump-profile-modal.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

html.is-profile-modal-active {
  overflow: hidden !important;
  height: 100% !important;
  overscroll-behavior: none !important;
  -webkit-overflow-scrolling: auto !important;
}

body.is-profile-modal-active {
  overflow: hidden !important;
  overscroll-behavior: none !important;
  touch-action: none;
}

body.is-profile-modal-active > *:not(.studydump-profile-modal):not(#studydump-profile-modal):not(.studydump-sync-modal):not(#studydump-sync-modal):not(script):not(style) {
  filter: blur(0px) !important;
  pointer-events: none !important;
  user-select: none !important;
  opacity: 0.15 !important;
}

@keyframes shakeCard {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.sd-profile-card {
  background: var(--bg-surface, #15181d);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-lg, 12px);
  width: 100%;
  max-width: 440px;
  box-shadow: var(--shadow-xl, 0 20px 40px rgba(0, 0, 0, 0.5));
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transform: scale(0.96) translateY(6px);
  transition: transform 0.24s cubic-bezier(0.16, 1, 0.3, 1);
  box-sizing: border-box;
}

.studydump-profile-modal.is-open .sd-profile-card {
  transform: scale(1) translateY(0);
}

.sd-profile-header {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.sd-profile-avatar-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md, 8px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.25));
  color: var(--accent, #7ba7d9);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.sd-profile-header-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.sd-profile-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  padding: 3px 10px;
  border-radius: 9999px;
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.25));
  color: var(--accent, #7ba7d9);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.sd-profile-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary, #e6edf3);
  margin: 0;
  letter-spacing: -0.015em;
  line-height: 1.25;
}

.sd-profile-subtitle {
  font-size: 0.84rem;
  line-height: 1.45;
  color: var(--text-secondary, #8b949e);
  margin: 0;
}

.sd-profile-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.sd-profile-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.sd-profile-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary, #8b949e);
  display: flex;
  align-items: center;
  gap: 4px;
}

.sd-required {
  color: #ef4444;
}

.sd-profile-input,
.sd-profile-select {
  width: 100%;
  padding: 10px 12px;
  background: var(--bg-canvas, #0d1117);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-sm, 6px);
  color: var(--text-primary, #e6edf3);
  font-size: 14px;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition-fast, 0.15s ease), box-shadow var(--transition-fast, 0.15s ease);
  box-sizing: border-box;
}

.sd-profile-input:focus,
.sd-profile-select:focus {
  border-color: var(--accent, #7ba7d9);
  box-shadow: 0 0 0 3px var(--accent-subtle, rgba(123, 167, 217, 0.2));
}

.sd-profile-hint {
  font-size: 0.73rem;
  color: var(--text-tertiary, #8b949e);
  margin-top: 2px;
  line-height: 1.35;
}

.sd-profile-error {
  font-size: 0.78rem;
  color: #f87171;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: var(--radius-sm, 6px);
  padding: 8px 12px;
}

.sd-profile-actions {
  margin-top: 4px;
}

.sd-profile-submit-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border-radius: var(--radius-sm, 6px);
  border: none;
  background: var(--accent, #7ba7d9);
  color: #0d1117;
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
  transition: filter var(--transition-fast, 0.15s ease), transform 0.1s ease;
}

.sd-profile-submit-btn:hover {
  filter: brightness(1.1);
}

.sd-profile-submit-btn:active {
  transform: scale(0.985);
}

.sd-profile-footer-sync {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding-top: 12px;
  border-top: 1px solid var(--border-default, #22262e);
  font-size: 0.78rem;
  color: var(--text-muted, #6e7681);
}

.sd-profile-sync-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: transparent;
  border: none;
  color: var(--accent, #7ba7d9);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  padding: 2px 4px;
  border-radius: var(--radius-xs, 4px);
  touch-action: manipulation;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity 0.15s ease, background-color 0.15s ease;
}

.sd-profile-sync-link:hover {
  opacity: 0.85;
}

/* Returning User Edit Profile Modal Styles */
.sd-profile-header-edit {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.sd-profile-user-summary {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.sd-profile-user-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1.5px solid var(--accent-border, rgba(123, 167, 217, 0.3));
  color: var(--accent, #7ba7d9);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  font-weight: 700;
  text-transform: uppercase;
  flex-shrink: 0;
}

.sd-profile-title-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.sd-profile-group-pill {
  display: inline-flex;
  align-items: center;
  padding: 1px 7px;
  border-radius: var(--radius-xs, 4px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.25));
  color: var(--accent, #7ba7d9);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.sd-profile-close-btn {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm, 6px);
  border: 1px solid var(--border-default, #22262e);
  background: transparent;
  color: var(--text-muted, #6e7681);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  touch-action: manipulation;
  transition: all var(--transition-fast, 0.15s ease);
}

.sd-profile-close-btn:hover {
  color: var(--text-primary, #e6edf3);
  border-color: var(--text-secondary, #8b949e);
  background: rgba(255, 255, 255, 0.05);
}

.sd-profile-sync-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  background: var(--bg-canvas, #0d1117);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-sm, 6px);
  margin-top: 2px;
}

.sd-profile-sync-panel-info {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.sd-profile-sync-panel-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-xs, 4px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  color: var(--accent, #7ba7d9);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.sd-profile-sync-panel-text {
  min-width: 0;
}

.sd-profile-sync-panel-title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary, #e6edf3);
}

.sd-profile-sync-panel-desc {
  font-size: 0.72rem;
  color: var(--text-muted, #6e7681);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sd-profile-sync-panel-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 10px;
  border-radius: var(--radius-xs, 4px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.3));
  color: var(--accent, #7ba7d9);
  font-size: 0.76rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  touch-action: manipulation;
  transition: all var(--transition-fast, 0.15s ease);
}

.sd-profile-sync-panel-btn:hover {
  background: var(--accent, #7ba7d9);
  color: #0d1117;
}

/* Connected Devices in Student Profile */
.sd-profile-sync-section {
  background: var(--bg-canvas, #0d1117);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-sm, 6px);
  padding: 10px 12px;
  margin-top: 2px;
}

.sd-profile-sync-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}

.sd-profile-sync-title-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.sd-profile-sync-title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary, #e6edf3);
}

.sd-profile-sync-code-pill {
  display: inline-flex;
  align-items: center;
  padding: 1px 6px;
  border-radius: var(--radius-xs, 4px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.25));
  color: var(--accent, #7ba7d9);
  font-size: 10.5px;
  font-family: var(--font-mono, monospace);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.sd-profile-devices-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 160px;
  overflow-y: auto;
}

.sd-device-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 8px;
  background: var(--bg-surface, #15181d);
  border: 1px solid var(--border-subtle, #1e2228);
  border-radius: var(--radius-xs, 4px);
  transition: all var(--transition-fast, 0.15s ease);
}

.sd-device-item.is-current {
  border-color: rgba(46, 160, 67, 0.35);
  background: rgba(46, 160, 67, 0.04);
}

.sd-device-icon-wrap {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-xs, 4px);
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  color: var(--accent, #7ba7d9);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.sd-device-item.is-current .sd-device-icon-wrap {
  background: rgba(46, 160, 67, 0.15);
  color: #3fb950;
}

.sd-device-info {
  flex: 1;
  min-width: 0;
}

.sd-device-name-row {
  display: flex;
  align-items: center;
  gap: 6px;
}

.sd-device-name {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-primary, #e6edf3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sd-device-tag {
  font-size: 9.5px;
  font-weight: 700;
  padding: 1px 5px;
  border-radius: 3px;
  white-space: nowrap;
}

.sd-device-tag.sd-device-current {
  background: rgba(46, 160, 67, 0.18);
  border: 1px solid rgba(46, 160, 67, 0.4);
  color: #3fb950;
}

.sd-device-meta {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.7rem;
  color: var(--text-muted, #6e7681);
}

.sd-device-dot {
  opacity: 0.6;
}

.sd-device-empty {
  padding: 8px;
  text-align: center;
  font-size: 0.74rem;
  color: var(--text-muted, #6e7681);
}

.sd-profile-edit-actions {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 10px;
  margin-top: 4px;
}

.sd-profile-cancel-btn {
  padding: 11px 14px;
  border-radius: var(--radius-sm, 6px);
  border: 1px solid var(--border-default, #22262e);
  background: var(--bg-canvas, #0d1117);
  color: var(--text-secondary, #8b949e);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast, 0.15s ease);
}

.sd-profile-cancel-btn:hover {
  background: var(--bg-surface, #15181d);
  color: var(--text-primary, #e6edf3);
  border-color: var(--text-secondary, #8b949e);
}

/* Header Profile Pill */
.header-profile-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  height: 38px;
  min-height: 38px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  touch-action: manipulation;
  transition: all var(--transition-fast);
  white-space: nowrap;
  flex-shrink: 0;
}

.header-profile-btn:hover {
  border-color: var(--border-strong);
  color: var(--accent);
}

.header-profile-name {
  max-width: 110px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.header-profile-group {
  font-size: 10.5px;
  padding: 1px 5px;
  border-radius: 4px;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent, #10b981);
  font-weight: 700;
}

/* Responsive Rules for Profile Modal & Header Profile */
@media (max-width: 768px) {
  .header-profile-btn {
    height: 34px;
    min-height: 34px;
    padding: 0 10px;
    gap: 5px;
    font-size: 11.5px;
  }
}

/* On mobile devices (<= 680px), show only the User icon; full name and group appear on tablets and desktops */
@media (max-width: 680px) {
  .header-profile-btn {
    width: 38px;
    min-width: 38px;
    height: 38px;
    min-height: 38px;
    padding: 0 !important;
    justify-content: center !important;
    gap: 0 !important;
  }

  .header-profile-btn svg {
    width: 15px;
    height: 15px;
  }

  .header-profile-name,
  .header-profile-group {
    display: none !important;
  }
}

@media (max-width: 480px) {
  .header-profile-btn {
    width: 34px;
    min-width: 34px;
    height: 34px;
    min-height: 34px;
    padding: 0 !important;
    justify-content: center !important;
  }

  .studydump-profile-modal {
    padding: 12px;
  }

  .sd-profile-card {
    padding: 20px 16px;
    gap: 14px;
    border-radius: 14px;
    max-height: calc(100dvh - 24px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .sd-profile-title {
    font-size: 1.2rem;
  }

  .sd-profile-subtitle {
    font-size: 0.8rem;
  }

  .sd-profile-submit-btn {
    padding: 11px 16px;
    font-size: 0.88rem;
  }
}

@media (max-height: 520px) {
  .sd-profile-card {
    padding: 16px 14px;
    gap: 10px;
    max-height: calc(100dvh - 16px);
  }

  .sd-profile-title {
    font-size: 1.1rem;
  }

  .sd-profile-form {
    gap: 10px;
  }
}

/* ==========================================================================
   Cross-Device Sync Modal & Toast Notifications
   ========================================================================== */

.studydump-sync-modal {
  position: fixed;
  inset: 0;
  z-index: 100010;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(4, 7, 14, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.16s ease, visibility 0.16s ease;
  padding: 16px;
  box-sizing: border-box;
}

.studydump-sync-modal.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

html.is-sync-modal-active {
  overflow: hidden !important;
  height: 100% !important;
  overscroll-behavior: none !important;
  -webkit-overflow-scrolling: auto !important;
}

body.is-sync-modal-active {
  overflow: hidden !important;
  overscroll-behavior: none !important;
  touch-action: none;
}

.sd-sync-card {
  position: relative;
  background: var(--bg-surface, #15181d);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-md, 8px);
  width: 100%;
  max-width: 480px;
  box-shadow: var(--shadow-modal, 0 20px 48px rgba(0, 0, 0, 0.65));
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transform: scale(0.96);
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  box-sizing: border-box;
}

.studydump-sync-modal.is-open .sd-sync-card {
  transform: scale(1);
}

.sd-sync-close-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  background: transparent;
  border: 1px solid var(--border-default, #22262e);
  color: var(--text-secondary, #8b909a);
  border-radius: var(--radius-xs, 4px);
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast, 140ms ease-out);
}

.sd-sync-close-btn:hover {
  background: var(--bg-surface-subtle, #1f232b);
  color: var(--text-primary, #d9dce2);
}

.sd-sync-header {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-right: 28px;
}

.sd-sync-title {
  font-family: var(--font-display, var(--font-sans, sans-serif));
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary, #d9dce2);
  margin: 0;
  letter-spacing: -0.015em;
}

.sd-sync-subtitle {
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--text-secondary, #8b909a);
  margin: 0;
}

.sd-sync-body {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 16px;
  align-items: stretch;
}

.sd-sync-col {
  display: flex;
  flex-direction: column;
}

.sd-sync-qr-col {
  align-items: center;
  justify-content: flex-start;
  gap: 8px;
}

.sd-sync-qr-wrapper {
  background: #ffffff;
  padding: 6px;
  border-radius: var(--radius-md, 6px);
  border: 1px solid var(--border-default, #22262e);
  box-shadow: var(--shadow-subtle, 0 2px 6px rgba(0, 0, 0, 0.2));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 140px;
  height: 140px;
  box-sizing: border-box;
}

.sd-sync-qrcode-canvas canvas,
.sd-sync-qrcode-canvas img {
  display: block;
  width: 128px !important;
  height: 128px !important;
  border-radius: 2px;
}

.sd-sync-qr-hint {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-secondary, #8b909a);
  text-align: center;
  margin: 0;
}

.sd-sync-form-col {
  justify-content: space-between;
  gap: 10px;
}

.sd-sync-code-box {
  background: var(--accent-subtle, rgba(123, 167, 217, 0.12));
  border: 1px solid var(--accent-border, rgba(123, 167, 217, 0.28));
  border-radius: var(--radius-sm, 6px);
  padding: 8px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.sd-sync-code-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sd-sync-code-label {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent, #7ba7d9);
}

.sd-sync-code-display {
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary, #d9dce2);
  letter-spacing: 0.08em;
}

.sd-sync-copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--bg-surface, #15181d);
  border: 1px solid var(--border-default, #22262e);
  color: var(--text-primary, #d9dce2);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 6px 10px;
  border-radius: var(--radius-xs, 4px);
  cursor: pointer;
  transition: all var(--transition-fast, 140ms ease-out);
  white-space: nowrap;
}

.sd-sync-copy-btn:hover {
  background: var(--accent-subtle);
  border-color: var(--accent-border);
  color: var(--accent);
}

.sd-sync-connect-form {
  display: flex;
  flex-direction: column;
}

.sd-sync-input-group {
  display: flex;
  gap: 6px;
}

.sd-sync-input {
  flex: 1;
  background: var(--bg-app, #0d0f12);
  border: 1px solid var(--border-default, #22262e);
  border-radius: var(--radius-xs, 4px);
  padding: 8px 10px;
  color: var(--text-primary, #d9dce2);
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.sd-sync-input:focus {
  border-color: var(--accent, #7ba7d9);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

.sd-sync-connect-btn {
  background: var(--accent, #7ba7d9);
  border: 1px solid var(--accent, #7ba7d9);
  color: var(--text-inverse, #0d0f12);
  font-weight: 700;
  font-size: 0.8rem;
  padding: 0 14px;
  border-radius: var(--radius-xs, 4px);
  cursor: pointer;
  transition: all var(--transition-fast, 140ms ease-out);
  white-space: nowrap;
}

.sd-sync-connect-btn:hover {
  filter: brightness(1.12);
}

.sd-sync-status-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2px;
}

.sd-sync-status-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.74rem;
  font-weight: 500;
  color: #10b981;
}

.sd-sync-pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  animation: sdPulse 1.8s infinite;
}

@keyframes sdPulse {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { box-shadow: 0 0 0 6px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.sd-sync-unlink-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary, #8b909a);
  font-size: 0.72rem;
  font-weight: 500;
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 4px;
  text-decoration: underline;
  transition: color var(--transition-fast);
}

.sd-sync-unlink-btn:hover {
  color: var(--callout-important-border, #e06050);
}

/* Toast Container */
.sd-toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.sd-toast-item {
  background: var(--bg-surface-elevated, #1b1f25);
  border: 1px solid var(--border-default, #22262e);
  box-shadow: var(--shadow-modal, 0 10px 25px rgba(0, 0, 0, 0.5));
  color: var(--text-primary, #d9dce2);
  padding: 10px 14px;
  border-radius: var(--radius-sm, 6px);
  font-size: 0.82rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transform: translateY(20px);
  opacity: 0;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: auto;
}

.sd-toast-item.show {
  transform: translateY(0);
  opacity: 1;
}

.sd-toast-item svg {
  color: #10b981;
  flex-shrink: 0;
}

@media (max-width: 540px) {
  .sd-sync-card {
    padding: 20px 16px;
    max-height: calc(100dvh - 32px);
    overflow-y: auto;
  }
  .sd-sync-body {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .sd-sync-qr-col {
    order: 2;
  }
  .sd-sync-form-col {
    order: 1;
  }
  .sd-toast-container {
    bottom: 16px;
    right: 16px;
    left: 16px;
  }
}

/* ==========================================================================
   Student Experience Feedback Modal (Streamlined & Device-Optimized)
   ========================================================================== */

.studydump-feedback-modal {
  position: fixed;
  inset: 0;
  z-index: 100002;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: rgba(13, 17, 23, 0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.22s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

.studydump-feedback-modal.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* Prevent underlying page scroll when student feedback modal is active across all devices */
html.is-feedback-modal-active {
  overflow: hidden !important;
  height: 100% !important;
  overscroll-behavior: none !important;
  -webkit-overflow-scrolling: auto !important;
}

body.is-feedback-modal-active {
  position: fixed !important;
  top: calc(var(--sd-fb-scroll-y, 0px) * -1) !important;
  left: 0 !important;
  right: 0 !important;
  width: 100% !important;
  height: 100% !important;
  overflow: hidden !important;
  overscroll-behavior: none !important;
  touch-action: none !important;
  padding-right: var(--sd-fb-scrollbar-width, 0px) !important;
}

.sd-fb-card {
  position: relative;
  width: 100%;
  max-width: 620px;
  max-height: min(90vh, 760px);
  background: #13171f;
  background: linear-gradient(180deg, #161b22 0%, #0d1117 100%);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md, 14px);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.65), 0 0 0 1px rgba(255, 255, 255, 0.05);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.96) translateY(10px);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.studydump-feedback-modal.is-open .sd-fb-card {
  transform: scale(1) translateY(0);
}

.sd-fb-header {
  padding: 14px 18px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: rgba(22, 27, 34, 0.85);
}

.sd-fb-header-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  flex: 1;
}

.sd-fb-title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary, #e6edf3);
  letter-spacing: -0.015em;
  line-height: 1.25;
}

.sd-fb-subtitle {
  margin: 0;
  font-size: 0.76rem;
  color: var(--text-secondary, #8b949e);
  line-height: 1.35;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sd-fb-header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.sd-fb-quick-all-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.32);
  color: #fbbf24;
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.sd-fb-quick-all-btn:hover {
  background: rgba(245, 158, 11, 0.22);
  border-color: rgba(245, 158, 11, 0.55);
  transform: translateY(-1px);
}

.sd-fb-close-btn {
  background: transparent;
  border: none;
  color: var(--text-tertiary, #8b949e);
  padding: 6px;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s ease, background 0.15s ease;
}

.sd-fb-close-btn:hover {
  color: var(--text-primary, #e6edf3);
  background: rgba(255, 255, 255, 0.08);
}

.sd-fb-form {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
}

.sd-fb-questions-scroll {
  padding: 10px 16px;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-height: 56vh;
}

.sd-fb-questions-scroll::-webkit-scrollbar {
  width: 5px;
}

.sd-fb-questions-scroll::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 4px;
}

.sd-fb-row,
.sd-fb-question-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.015);
  border: 1px solid transparent;
  transition: background 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.sd-fb-row:hover,
.sd-fb-question-card:hover {
  background: rgba(255, 255, 255, 0.035);
}

.sd-fb-row.is-highlight-error,
.sd-fb-question-card.is-highlight-error {
  border-color: #ef4444 !important;
  background: rgba(239, 68, 68, 0.08) !important;
  box-shadow: 0 0 0 2px rgba(239, 68, 68, 0.25) !important;
}

.sd-fb-row-info {
  display: flex;
  flex-direction: column;
  gap: 1px;
  min-width: 0;
  flex: 1;
}

.sd-fb-row-title {
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-primary, #e6edf3);
  letter-spacing: -0.01em;
}

.sd-fb-row-prompt {
  font-size: 0.73rem;
  color: var(--text-tertiary, #8b949e);
  line-height: 1.35;
}

.sd-fb-row-rating {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.sd-fb-stars-list {
  display: inline-flex;
  align-items: center;
  gap: 1px;
}

.sd-fb-star-btn {
  background: transparent;
  border: none;
  padding: 4px;
  border-radius: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #484f58;
  transition: transform 0.15s cubic-bezier(0.16, 1, 0.3, 1), color 0.15s ease;
  touch-action: manipulation;
  min-width: 32px;
  min-height: 32px;
}

.sd-fb-star-btn:hover {
  transform: scale(1.15);
  color: #fbbf24;
}

.sd-fb-star-btn:active {
  transform: scale(0.92);
}

.sd-fb-star-svg {
  transition: fill 0.15s ease, stroke 0.15s ease;
}

.sd-fb-rating-badge {
  display: inline-block;
  min-width: 24px;
  text-align: center;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-tertiary, #6e7681);
  transition: color 0.15s ease;
}

.sd-fb-rating-badge.is-rated {
  color: #f59e0b;
}

.sd-fb-suggestion-card {
  margin-top: 6px;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.sd-fb-suggestion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.sd-fb-suggestion-label {
  font-size: 0.77rem;
  font-weight: 600;
  color: var(--text-secondary, #c9d1d9);
  cursor: pointer;
}

.sd-fb-opt {
  font-size: 0.72rem;
  font-weight: 400;
  color: var(--text-tertiary, #6e7681);
}

.sd-fb-char-count {
  font-size: 0.68rem;
  color: var(--text-tertiary, #6e7681);
}

.sd-fb-textarea {
  width: 100%;
  background: var(--bg-canvas, #0d1117);
  border: 1px solid var(--border-default, #2d333b);
  border-radius: 6px;
  color: var(--text-primary, #e6edf3);
  padding: 7px 10px;
  font-size: 0.8rem;
  font-family: inherit;
  resize: vertical;
  min-height: 44px;
  max-height: 120px;
  box-sizing: border-box;
}

.sd-fb-textarea:focus {
  outline: none;
  border-color: var(--accent, #7ba7d9);
  box-shadow: 0 0 0 2px rgba(123, 167, 217, 0.2);
}

.sd-fb-error-bar {
  margin: 0 16px;
  padding: 7px 12px;
  border-radius: 6px;
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #f87171;
  font-size: 0.76rem;
  font-weight: 600;
}

.sd-fb-footer {
  padding: 12px 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  background: rgba(22, 27, 34, 0.95);
}

.sd-fb-btn-snooze {
  background: transparent;
  border: 1px solid var(--border-default, #30363d);
  color: var(--text-secondary, #8b949e);
  border-radius: var(--radius-sm, 6px);
  padding: 8px 14px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.sd-fb-btn-snooze:hover {
  color: var(--text-primary, #e6edf3);
  border-color: var(--text-tertiary, #6e7681);
}

.sd-fb-btn-submit {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent, #7ba7d9);
  color: #0d1117;
  border: none;
  border-radius: var(--radius-sm, 6px);
  padding: 8px 16px;
  font-size: 0.84rem;
  font-weight: 700;
  cursor: pointer;
  transition: filter 0.15s ease, transform 0.1s ease;
}

.sd-fb-btn-submit:hover {
  filter: brightness(1.1);
}

.sd-fb-btn-submit:active {
  transform: scale(0.98);
}

.sd-fb-success-view {
  padding: 36px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 10px;
}

.sd-fb-success-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: #10b981;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fbSuccessPop 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes fbSuccessPop {
  0% { transform: scale(0.6); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.sd-fb-success-title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary, #e6edf3);
}

.sd-fb-success-desc {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-secondary, #8b949e);
  max-width: 360px;
  line-height: 1.4;
}

.sd-fb-success-close-btn {
  margin-top: 4px;
  background: var(--accent, #7ba7d9);
  color: #0d1117;
  border: none;
  border-radius: var(--radius-sm, 6px);
  padding: 7px 22px;
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
}

/* Mobile & Touch Usability (< 580px) */
@media (max-width: 580px) {
  .studydump-feedback-modal {
    padding: 8px;
    align-items: flex-end;
  }
  .sd-fb-card {
    max-height: calc(100dvh - 16px);
    border-radius: 14px 14px 8px 8px;
    width: 100%;
  }
  .sd-fb-header {
    padding: 12px 14px 10px 14px;
  }
  .sd-fb-title {
    font-size: 1rem;
  }
  .sd-fb-subtitle {
    font-size: 0.72rem;
  }
  .sd-fb-quick-all-btn {
    padding: 3px 8px;
    font-size: 0.68rem;
  }
  .sd-fb-questions-scroll {
    padding: 8px 12px;
    max-height: calc(100dvh - 170px);
    gap: 6px;
  }
  .sd-fb-row,
  .sd-fb-question-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 8px 10px;
    background: rgba(255, 255, 255, 0.025);
    border: 1px solid rgba(255, 255, 255, 0.04);
  }
  .sd-fb-row-info {
    width: 100%;
  }
  .sd-fb-row-title {
    font-size: 0.82rem;
  }
  .sd-fb-row-prompt {
    font-size: 0.72rem;
  }
  .sd-fb-row-rating {
    width: 100%;
    justify-content: space-between;
    padding-top: 2px;
  }
  .sd-fb-star-btn {
    min-width: 38px;
    min-height: 38px;
    padding: 6px;
  }
  .sd-fb-star-svg {
    width: 22px;
    height: 22px;
  }
  .sd-fb-footer {
    padding: 10px 14px;
    padding-bottom: max(10px, env(safe-area-inset-bottom));
  }
  .sd-fb-btn-snooze,
  .sd-fb-btn-submit {
    padding: 9px 14px;
    font-size: 0.8rem;
  }
}