/* ==========================================================================
   GATE DA 2027 Study Platform - Master Stylesheet
   Cloned & Enhanced from GateXAIML (https://gatexaiml.in/)
   ========================================================================== */

:root {
  /* Dark Theme (Default) */
  --bg-primary: #0A0F1E;
  --bg-secondary: #0F172A;
  --bg-card: #16223B;
  --bg-hover: #1E2C48;
  --border-color: #1E2C48;
  --border-subtle: #2A3C60;
  
  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-faint: #64748B;
  
  --accent-amber: #FF9900;
  --accent-amber-glow: rgba(255, 153, 0, 0.18);
  --accent-amber-dark: #E68A00;
  
  --emerald: #10B981;
  --emerald-glow: rgba(16, 185, 129, 0.15);
  --blue: #3B82F6;
  --blue-glow: rgba(59, 130, 246, 0.15);
  --purple: #8B5CF6;
  --red: #EF4444;

  --sidebar-w: 290px;
  --topbar-h: 68px;
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.2);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
}

[data-theme="light"] {
  --bg-primary: #F8FAFC;
  --bg-secondary: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-hover: #F1F5F9;
  --border-color: #E2E8F0;
  --border-subtle: #CBD5E1;
  
  --text-main: #0F172A;
  --text-muted: #475569;
  --text-faint: #94A3B8;
  
  --accent-amber: #EA580C;
  --accent-amber-glow: rgba(234, 88, 12, 0.12);
  --accent-amber-dark: #C2410C;
  
  --emerald: #059669;
  --emerald-glow: rgba(5, 150, 105, 0.12);
  --blue: #2563EB;
  --blue-glow: rgba(37, 99, 235, 0.12);
  --purple: #7C3AED;
  --red: #DC2626;
  
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
}

/* Base Reset & Fonts */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6, .brand-font {
  font-family: 'Poppins', sans-serif;
  font-weight: 700;
  letter-spacing: -0.01em;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Layout Shell */
.app-shell {
  display: flex;
  min-height: 100vh;
}

/* ---------------- SIDEBAR ---------------- */
.sidebar {
  width: var(--sidebar-w);
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 1040;
  transition: transform 0.3s ease;
  overflow-y: auto;
}

.sidebar-header {
  height: var(--topbar-h);
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.brand-logo {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-amber), #F59E0B);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #000;
  font-weight: 900;
  font-size: 1.25rem;
  box-shadow: 0 0 16px var(--accent-amber-glow);
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand-badge {
  font-size: 0.68rem;
  padding: 2px 7px;
  border-radius: 999px;
  background-color: var(--accent-amber-glow);
  color: var(--accent-amber);
  border: 1px solid var(--accent-amber);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.sidebar-section-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-faint);
  letter-spacing: 0.08em;
  padding: 16px 20px 8px;
}

.sidebar-nav {
  padding: 8px 12px 24px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  flex-grow: 1;
}

.nav-link-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 9px 12px;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.nav-link-item i {
  font-size: 1.05rem;
  width: 20px;
  text-align: center;
  color: var(--text-faint);
  transition: var(--transition);
}

.nav-link-item:hover {
  background-color: var(--bg-hover);
  color: var(--text-main);
}

.nav-link-item:hover i {
  color: var(--accent-amber);
}

.nav-link-item.active {
  background: var(--accent-amber-glow);
  color: var(--accent-amber);
  font-weight: 600;
}

.nav-link-item.active i {
  color: var(--accent-amber);
}

.nav-link-item .badge-count {
  margin-left: auto;
  font-size: 0.72rem;
  background-color: var(--bg-hover);
  color: var(--text-muted);
  padding: 2px 7px;
  border-radius: 999px;
  font-weight: 600;
}

.nav-item-progress-wrap {
  width: 100%;
  margin-top: 4px;
}

.nav-progress-track {
  width: 100%;
  height: 4px;
  background-color: var(--bg-hover);
  border-radius: 999px;
  overflow: hidden;
}

.nav-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-amber), var(--emerald));
  border-radius: 999px;
  width: 0%;
  transition: width 0.4s ease;
}

/* ---------------- MAIN CONTENT AREA ---------------- */
.main-wrapper {
  margin-left: var(--sidebar-w);
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* ---------------- TOPBAR ---------------- */
.topbar {
  height: var(--topbar-h);
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 1030;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-grow: 1;
  max-width: 580px;
}

.search-box {
  position: relative;
  width: 100%;
}

.search-box input {
  width: 100%;
  padding: 9px 16px 9px 38px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.88rem;
  outline: none;
  transition: var(--transition);
}

.search-box input:focus {
  border-color: var(--accent-amber);
  box-shadow: 0 0 0 3px var(--accent-amber-glow);
}

.search-box i.search-icon {
  position: absolute;
  left: 13px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-faint);
  font-size: 0.9rem;
}

.search-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow);
  max-height: 400px;
  overflow-y: auto;
  display: none;
  z-index: 1050;
}

.search-result-item {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  transition: var(--transition);
}

.search-result-item:hover {
  background-color: var(--bg-hover);
}

.search-result-item .item-type {
  font-size: 0.68rem;
  text-transform: uppercase;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background-color: var(--bg-hover);
  color: var(--accent-amber);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Exam Countdown Chip */
.exam-countdown-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--accent-amber-glow);
  border: 1px solid var(--accent-amber);
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-amber);
}

.pulse-dot {
  width: 7px;
  height: 7px;
  background-color: var(--accent-amber);
  border-radius: 50%;
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.9); opacity: 1; box-shadow: 0 0 0 0 rgba(255, 153, 0, 0.7); }
  70% { transform: scale(1.3); opacity: 0.8; box-shadow: 0 0 0 8px rgba(255, 153, 0, 0); }
  100% { transform: scale(0.9); opacity: 1; }
}

/* Pomodoro Focus Timer */
.pomodoro-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.pomodoro-pill:hover {
  border-color: var(--emerald);
  color: var(--emerald);
}

.icon-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

.icon-btn:hover {
  background-color: var(--bg-hover);
  color: var(--text-main);
  border-color: var(--text-faint);
}

.mobile-menu-btn {
  display: none;
}

/* ---------------- CONTENT CONTAINER ---------------- */
.content-body {
  padding: 28px 32px 64px;
  flex-grow: 1;
}

/* ---------------- HERO / BANNER CARDS ---------------- */
.hero-banner {
  background: linear-gradient(135deg, #101B33 0%, #0F172A 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-bottom: 28px;
}

[data-theme="light"] .hero-banner {
  background: linear-gradient(135deg, #FFFFFF 0%, #F1F5F9 100%);
}

.hero-banner::after {
  content: "";
  position: absolute;
  top: -80px;
  right: -80px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, var(--accent-amber-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  background-color: var(--accent-amber-glow);
  border: 1px solid var(--accent-amber);
  color: var(--accent-amber);
  font-size: 0.76rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.hero-title {
  font-size: 1.85rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 10px;
}

.hero-subtitle {
  font-size: 0.96rem;
  color: var(--text-muted);
  max-width: 680px;
  margin-bottom: 22px;
}

/* Stat Counters Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}

.stat-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-subtle);
  box-shadow: var(--shadow);
}

.stat-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.stat-val {
  font-size: 1.5rem;
  font-weight: 800;
  line-height: 1.1;
  font-family: 'Poppins', sans-serif;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ---------------- SUBJECT CARDS GRID ---------------- */
.section-heading-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.subject-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

.subject-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent-amber);
  box-shadow: 0 12px 28px -6px rgba(0, 0, 0, 0.35);
}

.subject-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 14px;
}

.subject-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background-color: var(--bg-hover);
  color: var(--accent-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
}

.subject-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.35;
}

.subject-card-desc {
  font-size: 0.84rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 18px;
  flex-grow: 1;
}

.subject-meta-chips {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.subject-meta-chip {
  display: flex;
  align-items: center;
  gap: 5px;
}

/* Progress Bar Component */
.progress-container {
  margin-bottom: 14px;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.76rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.progress-track {
  width: 100%;
  height: 6px;
  background-color: var(--bg-hover);
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-amber), var(--emerald));
  border-radius: 999px;
  width: 0%;
  transition: width 0.4s ease;
}

/* ---------------- CHAPTER QUICK JUMP PILLS ---------------- */
.chapter-pills-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.chapter-pill {
  padding: 6px 14px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition);
}

.chapter-pill:hover, .chapter-pill.active {
  background-color: var(--accent-amber-glow);
  color: var(--accent-amber);
  border-color: var(--accent-amber);
}

/* ---------------- CHAPTER ACCORDIONS & VIDEO CARDS ---------------- */
.chapter-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  margin-bottom: 18px;
  overflow: hidden;
  transition: var(--transition);
}

.chapter-header {
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  background-color: var(--bg-card);
  user-select: none;
  transition: var(--transition);
}

.chapter-header:hover {
  background-color: var(--bg-hover);
}

.chapter-title-group {
  display: flex;
  align-items: center;
  gap: 14px;
}

.chapter-num-badge {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background-color: var(--bg-hover);
  color: var(--accent-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
}

.chapter-title-text {
  font-size: 1rem;
  font-weight: 700;
}

.chapter-meta-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.chapter-collapse-btn {
  font-size: 1.1rem;
  color: var(--text-faint);
  transition: transform 0.3s ease;
}

.chapter-card.open .chapter-collapse-btn {
  transform: rotate(180deg);
}

.chapter-body {
  padding: 20px 24px 24px;
  display: none;
}

.chapter-card.open .chapter-body {
  display: block;
}

/* Video Cards Row */
.videos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.video-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.video-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-subtle);
  box-shadow: var(--shadow-sm);
}

.video-card.watched {
  border-color: var(--emerald);
  opacity: 0.88;
}

.video-card.watched .video-thumb::before {
  content: "\f00c";
  font-family: "Font Awesome 6 Free";
  font-weight: 900;
  position: absolute;
  top: 10px;
  right: 10px;
  background-color: var(--emerald);
  color: #fff;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  z-index: 5;
}

.video-thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  background-color: #000;
  cursor: pointer;
  overflow: hidden;
}

.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.video-card:hover .video-thumb img {
  transform: scale(1.05);
}

.play-overlay-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 52px;
  height: 52px;
  background: rgba(15, 23, 42, 0.85);
  border: 2px solid var(--accent-amber);
  border-radius: 50%;
  color: var(--accent-amber);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  transition: var(--transition);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
}

.video-thumb:hover .play-overlay-btn {
  transform: translate(-50%, -50%) scale(1.12);
  background: var(--accent-amber);
  color: #000;
}

.video-info {
  padding: 14px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  justify-content: space-between;
}

.video-title {
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 12px;
  color: var(--text-main);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-bottom-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid var(--border-color);
}

/* Watched Checkbox */
.watch-check-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
}

.watch-check-label input {
  accent-color: var(--emerald);
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.theater-mode-btn {
  background: none;
  border: none;
  color: var(--text-faint);
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  padding: 4px 6px;
  border-radius: 4px;
}

.theater-mode-btn:hover {
  color: var(--accent-amber);
  background-color: var(--bg-hover);
}

/* ---------------- THEATER / STUDY ROOM MODAL ---------------- */
.theater-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(5, 8, 16, 0.95);
  backdrop-filter: blur(8px);
  z-index: 2000;
  display: none;
  flex-direction: column;
}

.theater-modal.open {
  display: flex;
}

.theater-header {
  height: 60px;
  padding: 0 24px;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}

.theater-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.theater-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  max-width: 600px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.theater-body {
  flex-grow: 1;
  display: flex;
  min-height: 0;
}

.theater-main-stage {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  padding: 20px 24px;
  overflow-y: auto;
}

.player-embed-wrap {
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: calc(100vh - 220px);
  background-color: #000;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-bottom: 16px;
}

.player-embed-wrap iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.player-controls-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 14px 20px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.theater-sidebar {
  width: 380px;
  background-color: var(--bg-secondary);
  border-left: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}

.theater-playlist-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.theater-playlist-items {
  flex-grow: 1;
  overflow-y: auto;
  padding: 10px;
}

.playlist-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 4px;
}

.playlist-item:hover {
  background-color: var(--bg-hover);
}

.playlist-item.active {
  background-color: var(--accent-amber-glow);
  border-left: 3px solid var(--accent-amber);
}

.playlist-item-thumb {
  width: 72px;
  aspect-ratio: 16 / 9;
  border-radius: 4px;
  object-fit: cover;
}

.playlist-item-info {
  flex-grow: 1;
  min-width: 0;
}

.playlist-item-title {
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--text-main);
}

/* Notes Pad in Theater Mode */
.theater-notes-section {
  padding: 16px 20px;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-card);
}

.notes-textarea {
  width: 100%;
  height: 110px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  padding: 10px;
  font-size: 0.85rem;
  resize: none;
  outline: none;
  font-family: inherit;
}

.notes-textarea:focus {
  border-color: var(--accent-amber);
}

/* ---------------- BUTTONS & CHIPS ---------------- */
.btn-primary {
  background: linear-gradient(135deg, var(--accent-amber), var(--accent-amber-dark));
  color: #000;
  font-weight: 700;
  border: none;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  transition: var(--transition);
  box-shadow: 0 4px 12px var(--accent-amber-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  filter: brightness(1.08);
}

.btn-secondary {
  background-color: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  font-weight: 600;
  padding: 9px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  transition: var(--transition);
}

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

.btn-sm {
  padding: 6px 12px;
  font-size: 0.8rem;
}

/* ---------------- PDF MODAL VIEWER ---------------- */
.pdf-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(5, 8, 16, 0.9);
  backdrop-filter: blur(8px);
  z-index: 2100;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.pdf-modal.open {
  display: flex;
}

.pdf-dialog {
  width: 90vw;
  height: 90vh;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.pdf-modal-header {
  padding: 14px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.pdf-frame {
  width: 100%;
  height: 100%;
  border: none;
}

/* ---------------- PRACTICE QUIZ ARENA ---------------- */
.quiz-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 24px;
}

.quiz-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

.quiz-badge-type {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  background-color: var(--blue-glow);
  color: var(--blue);
  border: 1px solid var(--blue);
}

.quiz-question-text {
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.6;
  margin-bottom: 22px;
}

.quiz-option {
  padding: 14px 18px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 10px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 12px;
  background-color: var(--bg-secondary);
}

.quiz-option:hover {
  background-color: var(--bg-hover);
  border-color: var(--border-subtle);
}

.quiz-option.selected {
  border-color: var(--accent-amber);
  background-color: var(--accent-amber-glow);
  font-weight: 600;
}

.quiz-option.correct {
  border-color: var(--emerald) !important;
  background-color: var(--emerald-glow) !important;
}

.quiz-option.incorrect {
  border-color: var(--red) !important;
  background-color: rgba(239, 68, 68, 0.12) !important;
}

.quiz-explanation {
  margin-top: 18px;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  background-color: var(--bg-hover);
  border-left: 4px solid var(--emerald);
  font-size: 0.88rem;
  display: none;
}

/* ---------------- FORMULA CHEATSHEETS ---------------- */
.formula-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 16px;
}

.formula-name {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--accent-amber);
}

.formula-math {
  background-color: var(--bg-primary);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  font-family: 'Consolas', 'Courier New', monospace;
  font-size: 0.95rem;
  margin-bottom: 10px;
  color: #F8FAFC;
  overflow-x: auto;
}

[data-theme="light"] .formula-math {
  background-color: #0F172A;
}

.formula-notes {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------------- RESPONSIVE MEDIA QUERIES ---------------- */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-wrapper {
    margin-left: 0;
  }
  
  .mobile-menu-btn {
    display: flex;
  }
  
  .sidebar-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1035;
    display: none;
  }
  
  .sidebar-backdrop.show {
    display: block;
  }
  
  .theater-body {
    flex-direction: column;
  }
  
  .theater-sidebar {
    width: 100%;
    height: 320px;
  }
}

@media (max-width: 640px) {
  .content-body {
    padding: 16px;
  }
  
  .hero-banner {
    padding: 22px;
  }
  
  .hero-title {
    font-size: 1.4rem;
  }
  
  .topbar {
    padding: 0 16px;
  }
  
  .exam-countdown-badge span.countdown-desc {
    display: none;
  }
}