/* ==========================================================================
   THEORETICA - Modern Theoretical Physics Curriculum Portal
   Design System: Deep Space Dark Mode, Glassmorphism & Quantum Glow Accents
   ========================================================================== */

:root {
  --bg-deep: #070a12;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(24, 34, 61, 0.85);
  --bg-elevated: #111a2e;
  --bg-subtle: rgba(255, 255, 255, 0.03);
  
  --border-subtle: rgba(255, 255, 255, 0.07);
  --border-glow: rgba(56, 189, 248, 0.35);
  --border-active: #38bdf8;
  
  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-faint: #64748b;
  
  --accent-cyan: #38bdf8;
  --accent-blue: #3b82f6;
  --accent-purple: #a855f7;
  --accent-indigo: #6366f1;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;
  
  --glow-cyan: 0 0 25px rgba(56, 189, 248, 0.25);
  --glow-purple: 0 0 25px rgba(168, 85, 247, 0.25);
  --glow-emerald: 0 0 25px rgba(16, 185, 129, 0.25);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.6), 0 0 0 1px var(--border-subtle);
  --shadow-dropdown: 0 20px 40px -15px rgba(0, 0, 0, 0.8), 0 0 0 1px var(--border-subtle);
  
  --font-sans: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --transition-normal: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-deep);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(56, 189, 248, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 25%, rgba(168, 85, 247, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 50% 80%, rgba(59, 130, 246, 0.05) 0%, transparent 50%);
  background-attachment: fixed;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-deep);
}
::-webkit-scrollbar-thumb {
  background: #1e293b;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #334155;
}

/* Container */
.app-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* Top Navigation Bar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(7, 10, 18, 0.85);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 32px;
}

.nav-content {
  max-width: 1440px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.2), rgba(168, 85, 247, 0.2));
  border: 1px solid rgba(56, 189, 248, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--glow-cyan);
  font-size: 22px;
}

.brand-text h1 {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #f8fafc 40%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.brand-tag {
  font-size: 0.72rem;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand-tag::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  display: inline-block;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: var(--transition-normal);
  border: 1px solid transparent;
  text-decoration: none;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-secondary);
  border-color: var(--border-subtle);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #fff;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0369a1, #1d4ed8);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
  transform: translateY(-1px);
}

.btn-danger {
  background: rgba(244, 63, 94, 0.1);
  color: #fb7185;
  border-color: rgba(244, 63, 94, 0.3);
}

.btn-danger:hover {
  background: rgba(244, 63, 94, 0.2);
  color: #fff;
  border-color: rgba(244, 63, 94, 0.5);
}

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

/* Hero & Academic Dashboard */
.dashboard-hero {
  background: linear-gradient(135deg, rgba(17, 26, 46, 0.8), rgba(15, 23, 42, 0.5));
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 36px 36px 28px;
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.dashboard-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-cyan), var(--accent-purple), transparent);
}

.hero-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 28px;
}

.hero-title-area {
  max-width: 720px;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border-radius: 100px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--accent-cyan);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.hero-title-area h2 {
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.hero-title-area p {
  color: var(--text-muted);
  font-size: 1.02rem;
  line-height: 1.6;
}

/* Stat Cards Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.stat-card {
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
}

.stat-card:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
}

.stat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-icon {
  font-size: 1.2rem;
  opacity: 0.8;
}

.stat-value {
  font-size: 1.9rem;
  font-weight: 800;
  color: #fff;
  line-height: 1.1;
  margin-bottom: 8px;
  font-feature-settings: "tnum";
}

.stat-sub {
  font-size: 0.8rem;
  color: var(--text-faint);
  display: flex;
  align-items: center;
  gap: 6px;
}

.stat-sub .badge-pct {
  color: var(--accent-cyan);
  font-weight: 700;
}

/* Master Progress Bar */
.master-progress-container {
  background: rgba(11, 16, 28, 0.8);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  border: 1px solid var(--border-subtle);
  margin-top: 20px;
}

.master-progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.master-progress-title {
  font-size: 0.95rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.master-progress-percent {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--accent-cyan);
  font-family: var(--font-mono);
}

.progress-track {
  width: 100%;
  height: 12px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 100px;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #38bdf8, #818cf8, #a855f7);
  border-radius: 100px;
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.6);
}

/* Section Tabs Navigation */
.view-tabs {
  display: flex;
  gap: 6px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 28px;
  overflow-x: auto;
  padding-bottom: 4px;
  scrollbar-width: thin;
  scrollbar-color: #1e293b transparent;
}

.tab-btn {
  background: transparent;
  color: var(--text-muted);
  border: none;
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  flex-shrink: 0;
  transition: var(--transition-normal);
  position: relative;
}

.tab-btn:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.03);
}

.tab-btn.active {
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.08);
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-cyan);
  box-shadow: 0 0 10px var(--accent-cyan);
  border-radius: 3px;
}

.tab-badge {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 100px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
}

.tab-btn.active .tab-badge {
  background: rgba(56, 189, 248, 0.2);
  color: #fff;
}

/* Search and Filter Controls */
.controls-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
  background: var(--bg-card);
  padding: 16px 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
}

.search-box {
  position: relative;
  flex: 1;
  min-width: 260px;
}

.search-box input {
  width: 100%;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 10px 16px 10px 40px;
  color: #fff;
  font-size: 0.92rem;
  font-family: inherit;
  outline: none;
  transition: var(--transition-normal);
}

.search-box input:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-faint);
  pointer-events: none;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.filter-select {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-family: inherit;
  cursor: pointer;
  outline: none;
  transition: var(--transition-normal);
}

.filter-select:focus {
  border-color: var(--accent-cyan);
}

/* Year Section */
.year-block {
  margin-bottom: 40px;
}

.year-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  padding: 16px 20px;
  background: linear-gradient(90deg, rgba(30, 41, 59, 0.7), rgba(15, 23, 42, 0.5));
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
}

.year-title-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.year-title-wrap h3 {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.year-badge {
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 100px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  border: 1px solid rgba(56, 189, 248, 0.3);
}

.year-progress-stat {
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.year-progress-stat strong {
  color: var(--accent-cyan);
  font-family: var(--font-mono);
}

/* Semesters Grid */
.semesters-container {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.semester-wrap {
  background: rgba(11, 16, 28, 0.6);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 22px;
}

.semester-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 10px;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 18px;
}

/* Course Card */
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.course-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(56, 189, 248, 0.3);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -10px rgba(0, 0, 0, 0.7);
}

.course-card.completed {
  border-color: rgba(16, 185, 129, 0.35);
  background: rgba(16, 185, 129, 0.04);
}

.course-card.completed::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--accent-emerald);
  box-shadow: 0 0 10px var(--accent-emerald);
}

.course-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.course-code-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.course-code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(56, 189, 248, 0.25);
}

.course-category-tag {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 4px;
}

/* Category colors */
.cat-math { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.cat-classical { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }
.cat-quantum { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.cat-statistical { background: rgba(236, 72, 153, 0.15); color: #f472b6; }
.cat-relativity { background: rgba(20, 184, 166, 0.15); color: #2dd4bf; }
.cat-qft { background: rgba(239, 68, 68, 0.15); color: #f87171; }
.cat-computational { background: rgba(14, 165, 233, 0.15); color: #38bdf8; }
.cat-condensed { background: rgba(139, 92, 246, 0.15); color: #a78bfa; }
.cat-frontier { background: rgba(244, 63, 94, 0.15); color: #fb7185; }
.cat-research { background: rgba(16, 185, 129, 0.15); color: #34d399; }

/* Checkbox Toggle Master */
.master-check-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: inherit;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: var(--transition-normal);
}

.master-check-btn:hover {
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
}

.custom-checkbox {
  width: 20px;
  height: 20px;
  border-radius: 6px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-normal);
}

.custom-checkbox.checked {
  background: var(--accent-emerald);
  border-color: var(--accent-emerald);
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.5);
}

.custom-checkbox.checked::after {
  content: '✓';
  color: #fff;
  font-weight: 800;
  font-size: 13px;
}

.course-name {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 4px;
}

.course-en-name {
  font-size: 0.82rem;
  color: var(--text-faint);
  font-style: italic;
  margin-bottom: 12px;
}

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

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

.course-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

/* Card Progress Mini */
.course-mini-progress {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.course-mini-progress .progress-track {
  height: 6px;
  flex: 1;
}

.course-mini-progress span {
  font-size: 0.76rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

.course-card-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.expand-details-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--accent-cyan);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition-normal);
}

.expand-details-btn:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: rgba(56, 189, 248, 0.35);
  color: #fff;
}

/* Expandable Drawer Content */
.course-expanded-content {
  display: none;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  animation: fadeIn 0.3s ease;
}

.course-expanded-content.show {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.section-subtitle {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  font-weight: 700;
  margin: 14px 0 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Subtopics List */
.subtopics-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.subtopic-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.03);
  cursor: pointer;
  transition: var(--transition-normal);
}

.subtopic-item:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.1);
}

.subtopic-item.completed {
  background: rgba(16, 185, 129, 0.06);
  border-color: rgba(16, 185, 129, 0.2);
}

.subtopic-text {
  flex: 1;
}

.subtopic-title {
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.subtopic-item.completed .subtopic-title {
  color: #fff;
  text-decoration: line-through;
  opacity: 0.85;
}

.subtopic-desc {
  font-size: 0.78rem;
  color: var(--text-faint);
  margin-top: 2px;
}

/* Key formulas box */
.formulas-box {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  margin-bottom: 14px;
  overflow-x: auto;
}

.formula-line {
  font-size: 0.95rem;
  padding: 4px 0;
  color: var(--accent-cyan);
}

/* Textbooks list */
.textbook-mini-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 14px;
}

.textbook-mini-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 10px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
}

.tb-info strong {
  color: var(--text-secondary);
}

.tb-info span {
  color: var(--text-faint);
  margin-left: 6px;
}

.tb-badge {
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-muted);
}

/* Lecture links */
.lecture-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.lecture-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border-radius: 100px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--accent-cyan);
  font-size: 0.78rem;
  text-decoration: none;
  transition: var(--transition-normal);
}

.lecture-chip:hover {
  background: var(--accent-cyan);
  color: #070a12;
  box-shadow: var(--glow-cyan);
}

/* Personal Course Notes */
.course-notes-area {
  margin-top: 14px;
}

.course-notes-area textarea {
  width: 100%;
  height: 80px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.84rem;
  resize: vertical;
  outline: none;
}

.course-notes-area textarea:focus {
  border-color: var(--accent-cyan);
}

.save-notes-btn {
  margin-top: 6px;
  align-self: flex-end;
}

/* ==========================================================================
   University Benchmarking Table View
   ========================================================================== */
.uni-table-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.uni-table-header-block {
  padding: 24px 28px;
  background: linear-gradient(90deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.6));
  border-bottom: 1px solid var(--border-subtle);
}

.uni-table-header-block h3 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 6px;
}

.uni-table-header-block p {
  color: var(--text-muted);
  font-size: 0.94rem;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.curriculum-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.curriculum-table th {
  background: rgba(11, 16, 28, 0.95);
  padding: 16px 20px;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-subtle);
  white-space: nowrap;
}

.curriculum-table td {
  padding: 18px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
  font-size: 0.9rem;
  vertical-align: top;
}

.curriculum-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.uni-name-cell strong {
  display: block;
  font-size: 1.05rem;
  color: #fff;
  margin-bottom: 4px;
}

.uni-badge-country {
  display: inline-block;
  font-size: 0.72rem;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
}

.curriculum-table ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.curriculum-table li {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.4;
  position: relative;
  padding-left: 14px;
}

.curriculum-table li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
}

/* ==========================================================================
   Prerequisites & Dependency Matrix View
   ========================================================================== */
.prereq-checker-box {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.8));
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 28px;
  margin-bottom: 32px;
}

.prereq-checker-box h3 {
  font-size: 1.35rem;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.prereq-select-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 18px 0;
}

.prereq-select-row select {
  flex: 1;
  min-width: 280px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  color: #fff;
  font-size: 0.95rem;
  font-family: inherit;
}

.prereq-status-result {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-top: 14px;
}

.prereq-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
}

.prereq-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 22px;
  display: flex;
  flex-direction: column;
}

.prereq-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.prereq-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.prereq-req-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.02);
  margin-bottom: 8px;
}

.prereq-tag-level {
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 700;
  text-transform: uppercase;
}

.lvl-temel { background: rgba(59, 130, 246, 0.2); color: #60a5fa; }
.lvl-orta { background: rgba(245, 158, 11, 0.2); color: #fbbf24; }
.lvl-ileri { background: rgba(168, 85, 247, 0.2); color: #c084fc; }
.lvl-zorunlu { background: rgba(239, 68, 68, 0.2); color: #f87171; }
.lvl-kritik { background: rgba(244, 63, 94, 0.2); color: #fb7185; }

/* ==========================================================================
   Textbook Library View
   ========================================================================== */
.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 20px;
}

.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
  position: relative;
}

.book-card:hover {
  border-color: rgba(168, 85, 247, 0.35);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px -10px rgba(0, 0, 0, 0.7);
}

.book-card.read {
  border-color: rgba(16, 185, 129, 0.4);
  background: rgba(16, 185, 129, 0.03);
}

.book-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
}

.book-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 4px;
  background: rgba(168, 85, 247, 0.15);
  color: var(--accent-purple);
  border: 1px solid rgba(168, 85, 247, 0.3);
}

.book-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 6px;
  color: #fff;
}

.book-author {
  font-size: 0.85rem;
  color: var(--text-cyan, #38bdf8);
  font-weight: 600;
  margin-bottom: 10px;
}

.book-desc {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

.book-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: auto;
}

/* Modals & Dialogs */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
}

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

.modal-box {
  background: #0f172a;
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-xl);
  max-width: 600px;
  width: 100%;
  padding: 28px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.9);
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.modal-header h3 {
  font-size: 1.3rem;
  color: #fff;
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.4rem;
  cursor: pointer;
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 2000;
}

.toast {
  background: #1e293b;
  border: 1px solid var(--border-subtle);
  color: #fff;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 10px;
  animation: slideIn 0.3s ease;
}

.toast.success {
  border-color: var(--accent-emerald);
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.3);
}

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* Responsive adjustments */
@media (max-width: 900px) {
  .hero-header {
    flex-direction: column;
  }
  .controls-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .courses-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .app-container {
    padding: 0 12px 60px;
  }
  .dashboard-hero {
    padding: 24px 18px;
  }
  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }
}