/* ==========================================================================
   StudyDump - Dedicated Subject Hub Styles
   A single, organized source for all academic material of a course.
   Notes · Official Documents · Question Banks · Resources
   ========================================================================== */

.subject-back-nav {
  margin-bottom: var(--space-6);
}

.subject-back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--text-tertiary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* ==========================================================================
   Subject Header & Identity
   ========================================================================== */

.subject-page-header {
  margin-bottom: var(--space-12);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--border-default);
}

.subject-page-topline {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
  font-size: var(--text-xs);
}

.subject-page-code {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

.subject-page-context {
  color: var(--text-secondary);
}

.subject-page-title {
  font-family: var(--font-editorial);
  font-size: clamp(1.5rem, 5.2vw, 2.5rem);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: var(--space-3);
  overflow-wrap: break-word;
  word-break: break-word;
}

.subject-page-desc {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
  max-width: 65ch;
  margin-bottom: var(--space-6);
}

.subject-coverage {
  padding: var(--space-4);
  margin-bottom: var(--space-5);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
}

.subject-coverage-summary,
.subject-coverage-units {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-4);
  align-items: center;
}

.subject-coverage-summary strong {
  color: var(--text-primary);
  font-size: var(--text-sm);
}

.subject-coverage-summary span,
.subject-coverage p {
  color: var(--text-tertiary);
  font-size: var(--text-xs);
}

.subject-coverage-units {
  margin-top: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  color: var(--text-secondary);
}

.subject-coverage p {
  margin: var(--space-3) 0 0;
  line-height: var(--leading-normal);
}

/* Quick Section Jump Bar */
.subject-jump-nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px 14px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  max-width: 100%;
  width: 100%;
}

.jump-nav-label {
  font-family: var(--font-mono);
  font-size: var(--text-3xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  font-weight: 600;
  flex-shrink: 0;
}

.jump-nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: nowrap;
  white-space: nowrap;
}

.jump-nav-link {
  color: var(--accent);
  font-weight: 500;
  text-decoration: none;
  touch-action: manipulation;
  padding: 2px 4px;
  transition: opacity var(--transition-fast);
}

.jump-nav-link:hover {
  text-decoration: underline;
}

/* ==========================================================================
   Resource Group Sections
   ========================================================================== */

.subject-content-groups {
  display: flex;
  flex-direction: column;
  gap: var(--space-16);
}

.resource-group-section {
  display: flex;
  flex-direction: column;
}

.resource-group-header {
  margin-bottom: var(--space-6);
}

.resource-group-desc {
  display: block;
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  margin-top: 2px;
}

/* ==========================================================================
   1. Notes Section (by Unit)
   ========================================================================== */

.subject-units-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-10);
}

.unit-section-block {
  display: flex;
  flex-direction: column;
}

.unit-section-header {
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--border-default);
}

.unit-section-num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-3xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-tertiary);
  margin-bottom: 2px;
}

.unit-section-title {
  font-family: var(--font-editorial);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.015em;
}

.unit-topics-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.unit-topic-row {
  border-bottom: 1px solid var(--border-subtle);
}

.unit-topic-link {
  display: grid;
  grid-template-columns: 36px 1fr 24px;
  align-items: baseline;
  padding: 12px 4px;
  gap: var(--space-3);
  text-decoration: none;
}

.unit-topic-idx {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  transition: color var(--transition-fast);
}

.unit-topic-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.unit-topic-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
  line-height: var(--leading-snug);
  overflow-wrap: break-word;
  word-break: break-word;
  transition: color var(--transition-fast);
}

.unit-topic-link:hover .unit-topic-title {
  color: var(--accent);
}

.unit-topic-link:hover .unit-topic-idx {
  color: var(--accent);
}

.unit-topic-source {
  font-size: var(--text-2xs);
  color: var(--text-tertiary);
}

.unit-topic-arrow {
  width: 14px;
  height: 14px;
  stroke: var(--text-tertiary);
  align-self: center;
  transition: stroke var(--transition-fast);
}

.unit-topic-link:hover .unit-topic-arrow {
  stroke: var(--accent);
}

/* Coming Soon State */
.unit-topic-row.coming-soon .unit-topic-link {
  cursor: default;
  opacity: 0.6;
}

.unit-topic-badge {
  font-family: var(--font-mono);
  font-size: var(--text-3xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
  background-color: var(--bg-surface);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   2. Document Rows (PDF Resources)
   Syllabus, CHO, Question Banks, PYQs, Other Docs
   Clean, unboxed editorial rows with subtle metadata
   ========================================================================== */

.doc-rows-list {
  display: flex;
  flex-direction: column;
}

.doc-row {
  display: grid;
  grid-template-columns: 24px 1fr auto;
  align-items: center;
  padding: 14px 4px;
  border-bottom: 1px solid var(--border-subtle);
  gap: var(--space-4);
}

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

.doc-icon-col {
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.doc-info-col {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.doc-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  line-height: var(--leading-snug);
  overflow-wrap: break-word;
  word-break: break-word;
  transition: color var(--transition-fast);
}

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

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

.doc-credit-line {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px;
  font-size: var(--text-2xs);
  color: var(--text-tertiary);
  margin-top: 4px;
  line-height: var(--leading-snug);
}

.doc-credit-badge {
  display: inline-flex;
  align-items: center;
  padding: 1.5px 7px;
  border-radius: var(--radius-pill);
  font-size: var(--text-3xs);
  font-weight: 500;
  text-transform: none;
  background-color: var(--bg-surface-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  line-height: 1.3;
  user-select: none;
}

.doc-credit-text {
  color: var(--text-secondary);
  font-size: var(--text-2xs);
  font-weight: 400;
}

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

.doc-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 7px 14px;
  min-height: 36px;
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  touch-action: manipulation;
  transition: color var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
  white-space: nowrap;
}

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

.doc-btn-open:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.doc-btn-download {
  background-color: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
}

.doc-btn-download:hover {
  background-color: var(--bg-surface);
  border-color: var(--border-default);
  color: var(--text-primary);
}

/* ==========================================================================
   Mobile Responsiveness
   ========================================================================== */

@media (max-width: 640px) {
  .subject-page-header {
    margin-bottom: var(--space-8);
    padding-bottom: var(--space-6);
  }

  .subject-content-groups {
    gap: var(--space-10);
  }

  .doc-row {
    grid-template-columns: 20px 1fr;
    gap: var(--space-3);
    align-items: flex-start;
  }

  .doc-actions-col {
    grid-column: 2 / -1;
    margin-top: var(--space-2);
    flex-wrap: wrap;
  }

  .unit-topic-link {
    grid-template-columns: 28px 1fr 20px;
    gap: var(--space-2);
    min-height: 44px;
  }
}

@media (max-width: 380px) {
  .doc-row {
    grid-template-columns: 16px 1fr;
    gap: var(--space-2);
  }

  .doc-title {
    font-size: 0.9375rem;
  }

  .unit-topic-link {
    grid-template-columns: 22px 1fr 16px;
  }

  .unit-topic-title {
    font-size: 0.9375rem;
  }
}

/* ==========================================================================
   Mock Assessments Section & Hub Cards
   ========================================================================== */

.subject-mocks-section {
  margin-top: var(--space-4);
}

.mocks-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-4);
}

.mock-hub-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: all var(--transition-fast);
  position: relative;
}

.mock-hub-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.mock-hub-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #34d399;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.25);
  padding: 2.5px 8px;
  border-radius: 9999px;
  width: fit-content;
}

.mock-hub-badge svg {
  color: #34d399;
  flex-shrink: 0;
}

.mock-hub-title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.35;
}

.mock-hub-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.mock-hub-card:hover .mock-hub-title a {
  color: var(--accent);
}

.mock-hub-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin: 0;
  flex: 1;
}

.mock-hub-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  margin-top: 4px;
  flex-wrap: wrap;
}

.mock-hub-meta {
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

.mock-hub-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.mock-hub-btn:hover {
  color: #ffffff;
  transform: translateX(2px);
}

/* Subject Topline Hero Mock Badge */
.subject-hero-mock-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 2px 8px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.28);
  border-radius: 9999px;
  color: var(--accent);
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  font-weight: 600;
  text-decoration: none;
  margin-left: var(--space-2);
  transition: all var(--transition-fast);
}

.subject-hero-mock-badge:hover {
  background: rgba(59, 130, 246, 0.2);
  border-color: var(--accent);
  color: #ffffff;
}