:root {
  /* Ultra-Premium Color Palette */
  --bg-dark: #050810;
  --bg-card: rgba(17, 25, 40, 0.75);
  --bg-hover: rgba(255, 255, 255, 0.1);
  --accent-primary: #6366f1; /* Indigo */
  --accent-secondary: #06b6d4; /* Cyan */
  --accent-glow: rgba(99, 102, 241, 0.3);
  --gold: #f59e0b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --glass-border: rgba(255, 255, 255, 0.08);
  --grad-premium: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
  --grad-surface: linear-gradient(180deg, rgba(255, 255, 255, 0.03) 0%, rgba(255, 255, 255, 0) 100%);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.4);
}

.light-theme {
  --bg-dark: #ffffff;
  --bg-card: rgba(241, 245, 249, 0.9);
  --bg-hover: rgba(0, 0, 0, 0.05);
  --text-main: #1e293b;
  --text-muted: #475569;
  --glass-border: rgba(0, 0, 0, 0.08);
  --grad-surface: linear-gradient(180deg, rgba(0, 0, 0, 0.01) 0%, rgba(0, 0, 0, 0) 100%);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
}

.light-theme body { background-color: #ffffff; }
.light-theme #particles-js { opacity: 0.2; filter: invert(1); }
.light-theme .topbar { background: rgba(255, 255, 255, 0.85); border-bottom: 1px solid rgba(0,0,0,0.05); }
.light-theme #appTitle { background: linear-gradient(135deg, #1e293b 0%, var(--accent-primary) 100%); -webkit-background-clip: text; }
.light-theme .choice { background: #f1f5f9; color: #1e293b; border-color: rgba(0,0,0,0.05); }
.light-theme .choice:hover { background: #e2e8f0; }
.light-theme .question { color: #0f172a; }
.light-theme .card h2 { background: linear-gradient(to right, var(--accent-primary), #1e293b); -webkit-background-clip: text; }
.light-theme .timer { background: #ffffff; color: var(--accent-primary); border-color: var(--accent-secondary); box-shadow: none; }
.light-theme .flashcard-front { background: #ffffff; color: #1e293b; }
.light-theme .achievement-badge { background: #f1f5f9; }
.light-theme #userNameDisplay { color: #1e293b; }
.light-theme .level-tag { background: rgba(99, 102, 241, 0.1); }
.light-theme .xp-tag { background: rgba(6, 182, 212, 0.1); }
.light-theme .streak-tag { background: rgba(245, 158, 11, 0.1); }
.light-theme .syllabus-item { background: #f1f5f9; }
.light-theme .formula-container { background: #f1f5f9; border-color: rgba(99, 102, 241, 0.1); }
.light-theme #formulaText { color: #1e293b; }
.light-theme .top-controls button { background: #ffffff; color: #1e293b; }
.light-theme .premiumBtn { background: #ffffff; color: #1e293b; }
.light-theme .subjectBtn { background: #ffffff; color: #1e293b; }



* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

body {
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

#particles-js {
  position: fixed;
  inset: 0;
  z-index: 0;
  opacity: 0.6;
}

/* Header Refinement */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(5, 8, 16, 0.85);
  backdrop-filter: blur(20px);
  padding: 1.25rem 8%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--glass-border);
}

/* User Info Header */
.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.avatar {
    font-size: 2rem;
    color: var(--accent-secondary);
}

.user-meta {
    display: flex;
    flex-direction: column;
}

#userNameDisplay {
    font-weight: 700;
    font-size: 1rem;
    color: white;
}

#userLevel {
    display: flex;
    gap: 8px;
    align-items: center;
}

.level-tag, .xp-tag, .streak-tag {
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 0.7rem;
    white-space: nowrap;
}

.level-tag { background: rgba(99, 102, 241, 0.2); color: var(--accent-primary); border: 1px solid rgba(99, 102, 241, 0.3); }
.xp-tag { background: rgba(6, 182, 212, 0.2); color: var(--accent-secondary); border: 1px solid rgba(6, 182, 212, 0.3); }
.streak-tag { background: rgba(245, 158, 11, 0.2); color: var(--gold); border: 1px solid rgba(245, 158, 11, 0.3); }

.top-controls {
  display: flex;
  gap: 12px;
}

/* Main Navigation */
.main-nav {
    display: flex;
    gap: 20px;
    background: rgba(255, 255, 255, 0.03);
    padding: 6px 20px;
    border-radius: 50px;
    border: 1px solid var(--glass-border);
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: 30px;
    transition: all 0.3s ease;
}

.nav-link i {
    font-size: 1rem;
}

.nav-link:hover {
    color: var(--accent-secondary);
    background: rgba(6, 182, 212, 0.1);
}

.nav-link.active {
    color: white;
    background: var(--grad-premium);
    box-shadow: 0 4px 12px var(--accent-glow);
}

@media (max-width: 1100px) {
    .nav-link span { display: none; }
    .main-nav { gap: 10px; }
}

@media (max-width: 650px) {
    .topbar { flex-direction: column; gap: 15px; padding: 1rem; }
    .main-nav { order: 3; width: 100%; justify-content: space-around; border-radius: 15px; }
}


.top-controls button {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  color: white;
  width: 44px;
  height: 44px;
  border-radius: 14px;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.top-controls button:hover {
  background: var(--bg-hover);
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
  transform: translateY(-2px) scale(1.05);
}

/* Layout */
main {
  position: relative;
  z-index: 5;
  width: 92%;
  max-width: 1200px;
  margin: 3rem auto;
  display: flex;
  flex-direction: column;
  gap: 3.5rem;
}

/* Landing Section */
.landing {
  text-align: center;
  animation: slideUp 0.8s ease-out;
}

.quote-container {
    margin: 0 auto 1.5rem;
    max-width: 600px;
    font-style: italic;
    color: var(--accent-secondary);
    background: rgba(255,255,255,0.02);
    padding: 10px 20px;
    border-radius: 12px;
    font-size: 0.9rem;
}

.formula-container {
    background: rgba(99, 102, 241, 0.05);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 1.25rem 2rem;
    border-radius: 20px;
    margin: 0 auto 2rem;
    max-width: 500px;
    text-align: center;
}

.formula-container small {
    display: block;
    color: var(--accent-primary);
    text-transform: uppercase;
    font-weight: 800;
    font-size: 0.7rem;
    letter-spacing: 1px;
    margin-bottom: 5px;
}

#formulaText {
    font-family: 'Space Mono', monospace;
    font-size: 1.1rem;
    color: white;
}

.recommendation-badge {
    display: inline-block;
    background: rgba(6,182,212,0.1);
    border: 1px solid rgba(6,182,212,0.3);
    color: var(--accent-secondary);
    padding: 0.5rem 1.25rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 2rem;
    animation: fadeIn 0.8s ease-out;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.25rem;
  font-weight: 400;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Search Bar */
.search-container {
    position: relative;
    max-width: 500px;
    margin: 0 auto 3rem;
    animation: fadeIn 1s ease;
}

#subjectSearch {
    width: 100%;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    padding: 1rem 1.5rem 1rem 3.5rem;
    border-radius: 20px;
    color: white;
    font-size: 1.1rem;
    outline: none;
    transition: all 0.3s;
}

#subjectSearch:focus {
    border-color: var(--accent-secondary);
    box-shadow: 0 0 20px var(--accent-glow);
    background: rgba(255,255,255,0.08);
}

.search-icon {
    position: absolute;
    left: 1.5rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.2rem;
}

/* Special Modes Grid */
.special-modes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  width: 100%;
  max-width: 800px;
  margin: 0 auto 4rem;
}

.premiumBtn {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  position: relative;
  overflow: hidden;
  color: white;
  padding: 1.5rem;
  border-radius: 24px;
  font-weight: 700;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
  text-align: left;
}

.premiumBtn::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--grad-premium);
  opacity: 0.1;
  transition: opacity 0.4s;
}

.premiumBtn:hover::after {
  opacity: 0.2;
}

.premiumBtn:first-child { border-left: 4px solid var(--accent-primary); }
.aik-glow { border-left: 4px solid #10b981 !important; }
.premiumBtn:last-child { border-left: 4px solid var(--accent-secondary); }

.aik-glow:hover {
    box-shadow: 0 0 25px rgba(16, 185, 129, 0.4);
    border-color: #10b981;
}

.premiumBtn:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
  border-color: rgba(255,255,255,0.2);
}

/* Subject Buttons Grid */
.subject-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 20px;
  width: 100%;
}

.subjectBtn {
  background: var(--bg-card);
  background-image: var(--grad-surface);
  border: 1px solid var(--glass-border);
  color: white;
  padding: 2.5rem 1.5rem;
  border-radius: 24px;
  font-weight: 700;
  font-size: 1.2rem;
  cursor: pointer;
  backdrop-filter: blur(10px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  position: relative;
}

.subjectBtn::before {
  content: '⚡';
  font-size: 2rem;
  margin-bottom: 15px;
  filter: drop-shadow(0 0 8px var(--accent-glow));
}

.subjectBtn:hover {
  background: var(--bg-hover);
  border-color: var(--accent-primary);
  box-shadow: 0 0 30px var(--accent-glow);
  transform: translateY(-10px) scale(1.02);
}

/* Quiz UI Overhaul */
.container {
  display: none;
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
}

.card {
  background: var(--bg-card);
  background-image: var(--grad-surface);
  backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: 32px;
  padding: 3.5rem;
  box-shadow: var(--shadow-xl);
  position: relative;
}

.card-header {
    margin-bottom: 2.5rem;
}

.card-header h2 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(to right, var(--gold), #fff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.progress-bar {
  height: 10px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar-inner {
  height: 100%;
  background: var(--grad-premium);
  border-radius: 10px;
  box-shadow: 0 0 15px var(--accent-glow);
}

.question {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 2.5rem;
  line-height: 1.4;
  color: #fff;
}

.choices {
  display: grid;
  gap: 16px;
}

.choice {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  padding: 1.25rem 2rem;
  border-radius: 18px;
  font-size: 1.15rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  transition: all 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.choice:hover {
  background: rgba(255, 255, 255, 0.07);
  border-color: var(--accent-secondary);
  transform: translateX(10px);
}

.choice.selected {
  border-width: 2px;
}

.choice.selected.correct {
  background: rgba(16, 185, 129, 0.15);
  border-color: #10b981;
  color: #34d399;
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.2);
}

.choice.selected.wrong {
  background: rgba(239, 68, 68, 0.15);
  border-color: #ef4444;
  color: #f87171;
  box-shadow: 0 0 20px rgba(239, 68, 68, 0.2);
}

.explanation-box {
    margin-top: 1.5rem;
    padding: 1rem 1.5rem;
    background: rgba(99, 102, 241, 0.1);
    border-left: 4px solid var(--accent-primary);
    border-radius: 8px;
    font-size: 0.95rem;
    color: var(--text-main);
    animation: fadeIn 0.3s ease;
}

/* Navigation & Timer */
.card-footer {
  margin-top: 3.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navigation {
    display: flex;
    gap: 12px;
}

.navigation button {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  color: white;
  padding: 1rem 2rem;
  border-radius: 16px;
  font-weight: 700;
  font-size: 1rem;
  cursor: pointer;
}

.navigation button:hover {
    background: var(--grad-premium);
    border-color: transparent;
    transform: scale(1.05);
}

.timer {
  font-family: 'Space Mono', monospace;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--accent-secondary);
  background: rgba(0,0,0,0.3);
  padding: 0.75rem 1.75rem;
  border-radius: 20px;
  border: 1px solid rgba(6, 182, 212, 0.3);
  box-shadow: inset 0 0 15px rgba(6, 182, 212, 0.1);
}

.timer.warning {
    color: #ef4444;
    border-color: #ef4444;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.6; }
    100% { opacity: 1; }
}

/* Score Card / Result */
.scoreCard {
    display: none;
    text-align: center;
    animation: zoomIn 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes zoomIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

.score-summary {
    background: var(--bg-card);
    padding: 4rem;
    border-radius: 32px;
    border: 1px solid var(--glass-border);
}

.score-summary h2 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    background: var(--grad-premium);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.score-summary p {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    color: var(--text-muted);
}

#restartBtn {
    background: var(--grad-premium);
    border: none;
    color: white;
    padding: 1.25rem 3rem;
    border-radius: 20px;
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
}

/* Leaderboard & Stats */
.stats-sections {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
}

.leaderboard, .stats-container {
  background: var(--bg-card);
  padding: 1.5rem;
  border-radius: 24px;
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px);
}

.stats-container {
    max-height: 400px;
}

#scoreChart {
    max-height: 250px !important;
}

.leaderboard h3, .stats-container h3 {
  margin-bottom: 1.25rem;
  font-size: 1.3rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.leaderboard li {
  background: rgba(255,255,255,0.03);
  margin-bottom: 8px;
  padding: 0.8rem 1.2rem;
  border-radius: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  border: 1px solid transparent;
}

.leaderboard li:hover {
    border-color: var(--glass-border);
    background: rgba(255,255,255,0.05);
    transform: scale(1.02);
}

.leaderboard li span {
    flex: 1;
    font-weight: 600;
}

.leaderboard li strong {
    color: var(--accent-secondary);
    font-size: 1.25rem;
}

/* Flashcards - Luxury variant */
.flashcard-overlay {
    position: fixed;
    inset: 0;
    background: rgba(5, 8, 16, 0.98);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(20px);
}

.flashcard-container {
    width: 90%;
    max-width: 600px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.flashcard-header-meta {
    width: 100%;
    display: flex;
    justify-content: space-between;
    margin-bottom: 2rem;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.9rem;
}

.close-flashcards {
    position: absolute;
    top: 30px;
    right: 30px;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 1001;
}

.flashcard {
    width: 100%;
    height: 380px;
    perspective: 1500px;
    cursor: pointer;
    margin-bottom: 2.5rem;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    transform-style: preserve-3d;
}

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

.flashcard-front, .flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 3rem;
    border-radius: 40px;
    border: 1px solid var(--glass-border);
    box-shadow: 0 30px 60px rgba(0,0,0,0.5);
    text-align: center;
}

.flashcard-front {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    font-size: 1.8rem;
    font-weight: 700;
}

.flashcard-front small {
    margin-top: 2rem;
    font-size: 0.8rem;
    color: var(--accent-secondary);
    opacity: 0.7;
}

.flashcard-back {
    background: var(--grad-premium);
    transform: rotateY(180deg);
}

.back-content h3 {
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 1rem;
    opacity: 0.8;
}

.back-content p {
    font-size: 1.5rem;
    line-height: 1.4;
    font-weight: 600;
}

.flashcard-controls {
    display: flex;
    gap: 15px;
    width: 100%;
}

.nav-card-btn {
    flex: 1;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    color: white;
    padding: 1rem;
    border-radius: 18px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.nav-card-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

/* Study Timer Button */
#pomodoroBtn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    color: #fff;
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
}

#pomodoroBtn:hover {
    background: #ef4444;
    color: #fff;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  main { width: 95%; margin: 1.5rem auto; gap: 2rem; }
  .topbar { padding: 0.8rem 4%; }
  .card { padding: 1.5rem; border-radius: 20px; }
  .question { font-size: 1.2rem; }
  .subject-buttons { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .subjectBtn { padding: 1.5rem 1rem; font-size: 1rem; }
  .stats-sections { grid-template-columns: 1fr; }
  .score-summary { padding: 2rem; }
  .score-summary h2 { font-size: 1.8rem; }
  .notes-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .note-card { padding: 1rem; }
  .syllabus-grid { grid-template-columns: 1fr; }
  .achievements-grid { grid-template-columns: repeat(2, 1fr); }
  #pdfFrame { height: 400px; }
  .special-modes { grid-template-columns: 1fr; }
  .premiumBtn { padding: 1rem; }
}

@media (max-width: 480px) {
  .nav-link { padding: 6px; }
  .nav-link i { font-size: 1.2rem; }
  .top-controls { gap: 8px; }
  .top-controls button { width: 38px; height: 38px; }
  .subject-buttons { grid-template-columns: 1fr; }
  .notes-grid { grid-template-columns: 1fr; }
}


/* Animations */
@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0px); }
}

/* Scientific Calculator Overlay */
.calc-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
}

.calc-container {
    width: 90%;
    max-width: 500px;
    height: 600px;
    background: var(--bg-dark);
    border: 1px solid var(--accent-primary);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 0 50px rgba(99, 102, 241, 0.3);
}

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

.calc-header span {
    font-weight: 700;
    color: var(--accent-primary);
}

.calc-header button {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.25rem;
    cursor: pointer;
}

.calc-container iframe {
    flex: 1;
    border: none;
    width: 100%;
}

.subjectBtn i {
    animation: float 3s ease-in-out infinite;
}
/* Syllabus Tracker Section */
.syllabus-tracker {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 32px;
    border: 1px solid var(--glass-border);
    animation: fadeIn 1s ease;
}

.syllabus-tracker h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 12px;
}

.syllabus-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.syllabus-item {
    background: rgba(255, 255, 255, 0.03);
    padding: 1rem 1.5rem;
    border-radius: 16px;
    display: flex;
    align-items: center;
    gap: 15px;
    cursor: pointer;
    border: 1px solid transparent;
}

.syllabus-item:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--glass-border);
}

.syllabus-item.completed {
    border-color: #10b981;
    background: rgba(16, 185, 129, 0.05);
}

.syllabus-item.completed span {
    text-decoration: line-through;
    color: var(--text-muted);
}

.checkbox-custom {
    width: 20px;
    height: 20px;
    border: 2px solid var(--accent-secondary);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.completed .checkbox-custom {
    background: #10b981;
    border-color: #10b981;
}

.completed .checkbox-custom::after {
    content: '✓';
    color: white;
    font-size: 12px;
    font-weight: 900;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Achievements Section */
.achievements-container {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 32px;
    border: 1px solid var(--glass-border);
    animation: fadeIn 1.2s ease;
    margin-top: 2rem;
}

.achievements-container h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 12px;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 20px;
}

.achievement-badge {
    background: rgba(255, 255, 255, 0.03);
    padding: 1.5rem 1rem;
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    text-align: center;
    border: 1px solid transparent;
    opacity: 0.4;
    filter: grayscale(1);
    transition: all 0.5s ease;
}

.achievement-badge.unlocked {
    opacity: 1;
    filter: grayscale(0);
    background: rgba(245, 158, 11, 0.05);
    border-color: rgba(245, 158, 11, 0.3);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(245, 158, 11, 0.1);
}

.achievement-badge i {
    font-size: 2.5rem;
    color: var(--text-muted);
}

.unlocked i {
    color: var(--gold);
    text-shadow: 0 0 15px rgba(245, 158, 11, 0.5);
}

.achievement-badge span {
    font-weight: 700;
    font-size: 0.85rem;
}

.achievement-badge small {
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Notes Section Styling */
.notes-container {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 32px;
    padding: 2.5rem;
    margin-top: 3rem;
    box-shadow: var(--shadow-xl);
    animation: fadeIn 1s ease;
}

.notes-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 15px;
}

#pdfFrame {
    width: 100%;
    height: 700px;
    border-radius: 20px;
    border: 1px solid var(--glass-border);
    background: white;
}

#downloadPDF {
    background: var(--grad-premium);
    color: white;
    padding: 0.8rem 1.8rem;
    border-radius: 14px;
    text-decoration: none;
    font-weight: 700;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px var(--accent-glow);
}

#downloadPDF:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px var(--accent-glow);
}

#toggleNotes {
    background: rgba(255,255,255,0.05);
    border: 1px solid var(--glass-border);
    color: var(--text-main);
    padding: 0.8rem 1.5rem;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
}

#toggleNotes:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
}

/* Notes Grid for Dashboard */
.notes-grid-section {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 32px;
    border: 1px solid var(--glass-border);
    margin-top: 2rem;
}

.notes-grid-section h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 12px;
}

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 1.5rem;
}

.note-card {
    background: rgba(255, 255, 255, 0.03);
    padding: 1.5rem;
    border-radius: 24px;
    text-align: center;
    border: 1px solid transparent;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.note-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: var(--accent-secondary);
    transform: translateY(-5px);
}

.note-card i {
    font-size: 2.2rem;
    color: var(--accent-secondary);
}

.note-card span {
    font-weight: 700;
    font-size: 1.1rem;
}

.btn-download-note {
    background: rgba(6, 182, 212, 0.1);
    color: var(--accent-secondary);
    border: 1px solid rgba(6, 182, 212, 0.3);
    padding: 6px 15px;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-download-note:hover {
    background: var(--accent-secondary);
    color: white;
}