/* ============================================================
   LESSON PAGE — Premium 2026 Notes Library
   ============================================================ */

/* ── Layout ── */
.lesson-main {
  padding-bottom: 4rem;
}

/* ============================================================
   LESSON HERO
   ============================================================ */
.lesson-hero {
  text-align: center;
  padding: 3.5rem 0 2rem;
  position: relative;
}

/* Ambient glow for lesson hero */
.lesson-hero::before {
  content: '';
  position: absolute;
  top: 0; left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 300px;
  background: radial-gradient(ellipse at 50% 0%, rgba(155,28,49,0.15) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.lesson-hero > * {
  position: relative;
  z-index: 1;
}

.lesson-hero h1 {
  font-size: clamp(2.2rem, 4vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  background: linear-gradient(135deg, #f0f4f8 30%, #c0c8d2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.75rem;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-weight: 400;
}

/* ── Search bar ── */
.search-wrapper {
  position: relative;
  max-width: 580px;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: 0.9rem 1.5rem 0.9rem 3.2rem;
  font-size: 1rem;
  font-family: inherit;
  background: rgba(18,22,30,0.85);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 999px;
  color: var(--text-color);
  outline: none;
  backdrop-filter: blur(12px);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    background var(--transition-fast);
}

.search-input:focus {
  border-color: rgba(155,28,49,0.55);
  background: rgba(18,22,30,0.98);
  box-shadow:
    0 0 0 3px rgba(155,28,49,0.12),
    0 4px 20px rgba(155,28,49,0.12);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.light-theme .search-input {
  background: rgba(255,255,255,0.88);
  border-color: rgba(0,0,0,0.08);
}

.light-theme .search-input:focus {
  background: #ffffff;
  border-color: rgba(155,28,49,0.45);
}

.search-icon {
  position: absolute;
  left: 1.2rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.1rem;
  opacity: 0.45;
  pointer-events: none;
}

/* ============================================================
   TOP CONTRIBUTORS CARD
   ============================================================ */
.contributors-section {
  margin: 2rem auto;
  max-width: 520px;
}

.contributors-card {
  background: rgba(14,18,26,0.85);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 20px;
  padding: 1.5rem 2rem;
  box-shadow:
    0 8px 32px rgba(0,0,0,0.35),
    0 0 0 1px rgba(155,28,49,0.06);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.light-theme .contributors-card {
  background: rgba(255,255,255,0.88);
  border-color: rgba(0,0,0,0.07);
}

.contributors-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--text-color);
  letter-spacing: -0.015em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.contributors-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.contributor-row {
  display: flex;
  align-items: center;
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  transition: background var(--transition-fast);
  border-radius: 8px;
  padding-inline: 0.5rem;
}

.light-theme .contributor-row {
  border-bottom-color: rgba(0,0,0,0.05);
}

.contributor-row:last-child {
  border-bottom: none;
}

.rank {
  font-size: 1.3rem;
  margin-right: 0.75rem;
  min-width: 2rem;
  text-align: center;
}

.name {
  flex: 1;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--text-color);
}

.count {
  background: rgba(155,28,49,0.12);
  padding: 0.22rem 0.85rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  color: #f87171;
  border: 1px solid rgba(155,28,49,0.3);
  letter-spacing: 0.01em;
}

/* ============================================================
   FILTER PILLS
   ============================================================ */
.filters-section {
  margin: 1.5rem auto 0;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  -webkit-overflow-scrolling: touch;
}

.filter-pills {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  border: 1.5px solid rgba(255,255,255,0.15);
  background: rgba(255,255,255,0.05);
  color: #e0e0e0;
  transition: all 0.2s ease;
  font-family: inherit;
}

.pill-emoji {
  font-size: 15px;
  line-height: 1;
  flex-shrink: 0;
}

.pill:hover {
  background: rgba(255,255,255,0.10);
  border-color: rgba(255,255,255,0.3);
}

.pill.active {
  background: #e53e3e;
  border-color: #e53e3e;
  color: #ffffff;
  font-weight: 600;
}

.light-theme .pill {
  background: rgba(0,0,0,0.05);
  border-color: rgba(0,0,0,0.15);
  color: #333;
}

.light-theme .pill:hover {
  background: rgba(0,0,0,0.10);
  border-color: rgba(0,0,0,0.25);
}

.light-theme .pill.active {
  background: #e53e3e;
  border-color: #e53e3e;
  color: #fff;
}

/* ============================================================
   NOTES GRID
   ============================================================ */
.notes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 1.75rem;
}

/* ── Note card ── */
.note-card {
  background: rgba(14, 18, 26, 0.88);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 18px;
  padding: 1.4rem 1.5rem;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow:
    0 4px 20px rgba(0,0,0,0.4),
    0 0 0 1px rgba(155,28,49,0.05);
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  position: relative;
  overflow: hidden;
  transition:
    transform 0.25s cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 0.25s ease,
    border-color 0.25s ease;
}

/* Accent strip */
.note-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(155,28,49,0.5), transparent);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.note-card:hover {
  transform: translateY(-5px);
  border-color: rgba(155,28,49,0.3);
  box-shadow:
    0 8px 32px rgba(0,0,0,0.5),
    0 0 0 1px rgba(155,28,49,0.2),
    0 0 20px rgba(155,28,49,0.1);
}

.note-card:hover::before {
  opacity: 1;
}

.light-theme .note-card {
  background: rgba(255,255,255,0.9);
  border-color: rgba(0,0,0,0.06);
  box-shadow: 0 2px 16px rgba(0,0,0,0.08);
}

/* Note header */
.note-card-header {
  display: flex;
  align-items: center;
  gap: 0.7rem;
}

.note-file-icon {
  font-size: 1.5rem;
  line-height: 1;
  flex-shrink: 0;
}

.note-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-color);
  margin: 0;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

/* Subject pill */
.note-subject {
  display: inline-block;
  padding: 0.22rem 0.75rem;
  border: 1px solid rgba(220,38,38,0.4);
  border-radius: 999px;
  background: rgba(220,38,38,0.07);
  font-size: 0.74rem;
  font-weight: 700;
  color: #f87171;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  align-self: flex-start;
}

/* Meta row */
.note-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  align-items: center;
}

.note-meta span {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

/* Action buttons */
.note-footer {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: auto;
  padding-top: 0.35rem;
}

.download-btn {
  padding: 0.4rem 1rem;
  border-radius: 999px;
  font-size: 0.79rem;
  font-weight: 700;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(220,38,38,0.09);
  border: 1px solid rgba(220,38,38,0.5);
  color: #f87171;
  font-family: inherit;
  letter-spacing: 0.01em;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    transform var(--transition-fast);
}

.download-btn:hover {
  background: rgba(220,38,38,0.2);
  border-color: rgba(220,38,38,0.75);
  box-shadow: 0 0 12px rgba(220,38,38,0.3);
  transform: translateY(-1px);
  color: #fca5a5;
}

.preview-btn {
  padding: 0.4rem 1rem;
  border-radius: 999px;
  font-size: 0.79rem;
  font-weight: 700;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.12);
  color: var(--text-secondary);
  font-family: inherit;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    transform var(--transition-fast);
}

.preview-btn:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.22);
  transform: translateY(-1px);
  color: var(--text-color);
}

/* ── Empty state ── */
.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 4rem 2rem;
  background: rgba(14,18,26,0.6);
  border-radius: 24px;
  border: 1px dashed rgba(155,28,49,0.3);
  color: var(--text-secondary);
  font-size: 1.1rem;
  backdrop-filter: blur(4px);
}

.empty-state span {
  font-size: 3rem;
  display: block;
  margin-bottom: 1rem;
}

.loading-indicator {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 992px) {
  .notes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .lesson-hero h1 {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 0.95rem;
  }

  .contributors-card {
    padding: 1.2rem;
  }
}

@media (max-width: 600px) {
  .notes-grid {
    grid-template-columns: 1fr;
  }

  .filter-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    overflow-x: visible;
    white-space: normal;
    justify-content: flex-start;
    padding-bottom: 0;
  }

  .pill {
    flex-shrink: 0;
    white-space: nowrap;
  }

  .filters-section {
    overflow-x: visible;
  }
}

/* ============================================================
   LESSON PREVIEW MODAL
   ============================================================ */
.lesson-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  background: rgba(10, 12, 16, 0.75);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 1;
  transition: opacity 0.3s ease;
}

.lesson-modal-overlay.hidden {
  display: none !important;
}

.lesson-modal-container {
  background: rgba(18, 22, 30, 0.95);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
  width: min(1400px, 96vw);
  height: 92vh;
  height: 92dvh;
  border-radius: 16px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(1);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.lesson-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  background: rgba(10, 12, 16, 0.8);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  flex-shrink: 0;
}

.lesson-modal-title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-color, #fff);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 60%;
}

.lesson-modal-actions {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

.lesson-modal-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary, #a0a8b4);
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  font-size: 0.85rem;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  transition: all 0.2s;
}

.lesson-modal-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.2);
}

.lesson-modal-btn.close-btn {
  font-size: 1.1rem;
  padding: 0.2rem 0.6rem;
  background: rgba(220, 38, 38, 0.1);
  color: #f87171;
  border-color: rgba(220, 38, 38, 0.2);
}

.lesson-modal-btn.close-btn:hover {
  background: rgba(220, 38, 38, 0.2);
  color: #fff;
}

.lesson-modal-body {
  flex: 1;
  position: relative;
  background: #111;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

.lesson-modal-iframe {
  width: 100%;
  height: 100%;
  border: none;
  background: #111;
  display: block;
  -webkit-overflow-scrolling: touch;
}

.lesson-modal-iframe.hidden {
  opacity: 0;
}

.lesson-modal-loader {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.5);
  z-index: 2;
}

.lesson-modal-loader .spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255, 255, 255, 0.1);
  border-top-color: #e53e3e;
  border-radius: 50%;
  animation: modal-spin 1s linear infinite;
}

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

.lesson-modal-fallback {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(14, 18, 26, 0.95);
  z-index: 2;
  gap: 1.2rem;
  padding: 2rem;
  text-align: center;
  color: #fff;
}

.lesson-modal-fallback.hidden {
  display: none !important;
}

.fallback-icon-wrapper {
  width: 70px;
  height: 70px;
  background: rgba(155, 28, 49, 0.1);
  border: 1px solid rgba(155, 28, 49, 0.2);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.5rem;
  box-shadow: 0 8px 24px rgba(155, 28, 49, 0.15);
}

.fallback-icon {
  font-size: 2.2rem;
  line-height: 1;
}

.fallback-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0;
  color: var(--text-color, #fff);
  max-width: 90%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.fallback-desc {
  font-size: 0.95rem;
  color: var(--text-secondary, #a0a8b4);
  max-width: 300px;
  margin: 0;
  line-height: 1.4;
}

.fallback-btn {
  margin-top: 0.5rem;
  background: linear-gradient(135deg, #9B1C31, #c0394e);
  color: #fff !important;
  border: none;
  padding: 0.8rem 1.8rem;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(155, 28, 49, 0.4);
  transition: all 0.2s ease;
}

.fallback-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(155, 28, 49, 0.6);
  background: linear-gradient(135deg, #b22b40, #d64157);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .lesson-modal-container {
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    max-width: 100vw;
    max-height: 100dvh;
    border-radius: 0;
    border: none;
    inset: 0;
  }
  
  .lesson-modal-title {
    font-size: 0.9rem;
    max-width: 50%;
  }
  
  .lesson-modal-header {
    padding: 0.75rem 1rem;
    flex-shrink: 0;
  }
  
  .lesson-modal-body {
    flex: 1;
    height: auto;
    min-height: 0;
    width: 100%;
  }

  .lesson-modal-iframe {
    width: 100%;
    height: 100%;
    border: none;
  }
  
  .lesson-modal-btn {
    padding: 0.3rem 0.6rem;
    font-size: 0.8rem;
  }
}

/* ============================================================
   LIGHT THEME OVERRIDES (VISIBILITY FIX)
   ============================================================ */
.light-theme .lesson-hero h1 {
  background: linear-gradient(135deg, #111827 30%, #374151 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.light-theme .hero-subtitle { color: #374151; font-weight: 500; }
.light-theme .search-input { color: #111827; }
.light-theme .search-input::placeholder { color: #6B7280; }
.light-theme .search-icon { opacity: 0.6; color: #111827; }

.light-theme .contributors-title { color: #111827; font-weight: 700; }
.light-theme .name { color: #111827; font-weight: 600; }
.light-theme .count { color: #9B1C31; background: rgba(155,28,49,0.1); border-color: rgba(155,28,49,0.2); }

.light-theme .pill { color: #374151; font-weight: 600; }
.light-theme .pill.active { color: #ffffff; }

.light-theme .note-title { color: #111827; font-weight: 700; }
.light-theme .note-meta { color: #6B7280; }
.light-theme .note-subject { color: #9B1C31; border-color: rgba(155,28,49,0.3); background: rgba(155,28,49,0.05); }
.light-theme .empty-state { color: #374151; border-color: rgba(155,28,49,0.2); }
.light-theme .loading-indicator { color: #6B7280; }
.light-theme .preview-btn { color: #374151; border-color: rgba(0,0,0,0.15); background: rgba(0,0,0,0.03); }
.light-theme .preview-btn:hover { color: #111827; background: rgba(0,0,0,0.08); }
.light-theme .download-btn { color: #9B1C31; }
.light-theme .download-btn:hover { color: #b22b40; background: rgba(155,28,49,0.15); }