/* --- DESIGN SYSTEM & CUSTOM PROPERTIES --- */
:root {
  /* Fonts */
  --font-primary: 'Outfit', 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  /* Shared Base colors */
  --success: #10b981;
  --success-glow: rgba(16, 185, 129, 0.15);
  --error: #ef4444;
  --error-glow: rgba(239, 68, 68, 0.15);
  --warning: #f59e0b;
  --warning-glow: rgba(245, 158, 11, 0.15);
  --info: #06b6d4;
  --info-glow: rgba(6, 182, 212, 0.15);
  
  /* Transition timings */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Border radii */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-round: 50%;
}

/* Dark Theme (Default) */
body, body.dark-theme {
  --bg-app: #09090b;
  --bg-color: #09090b;
  --bg-app-rgb: 9, 9, 11;
  --bg-card: rgba(20, 20, 25, 0.65);
  --bg-card-hover: rgba(28, 28, 35, 0.8);
  --card-bg: rgba(20, 20, 25, 0.65);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(99, 102, 241, 0.4);
  
  --text-main: #f4f4f5;
  --text-color: #f4f4f5;
  --text-muted: #a1a1aa;
  --text-inverse: #09090b;
  
  --primary: #6366f1;
  --primary-rgb: 99, 102, 241;
  --primary-hover: #4f46e5;
  --primary-glow: rgba(99, 102, 241, 0.15);
  
  --secondary: #a855f7;
  --secondary-rgb: 168, 85, 247;
  
  --accent: #f59e0b;
  --accent-glow: rgba(245, 158, 11, 0.15);
  
  --glass-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.5);
  --glass-bg: rgba(15, 15, 20, 0.7);
}

/* Light Theme */
body.light-theme {
  --bg-app: #f8fafc;
  --bg-color: #f8fafc;
  --bg-app-rgb: 248, 250, 252;
  --bg-card: rgba(255, 255, 255, 0.75);
  --bg-card-hover: rgba(255, 255, 255, 0.9);
  --card-bg: rgba(255, 255, 255, 0.75);
  --border-color: rgba(15, 23, 42, 0.08);
  --border-focus: rgba(79, 70, 229, 0.4);
  
  --text-main: #0f172a;
  --text-color: #0f172a;
  --text-muted: #64748b;
  --text-inverse: #ffffff;
  
  --primary: #4f46e5;
  --primary-rgb: 79, 70, 229;
  --primary-hover: #4338ca;
  --primary-glow: rgba(79, 70, 229, 0.08);
  
  --secondary: #9333ea;
  --secondary-rgb: 147, 51, 234;
  
  --accent: #d97706;
  --accent-glow: rgba(217, 119, 6, 0.1);
  
  --glass-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.06);
  --glass-bg: rgba(255, 255, 255, 0.75);
}

/* --- RESET & BASE STYLES --- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: var(--font-primary);
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-app);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

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

button, input, select, textarea {
  background: none;
  border: none;
  font: inherit;
  color: inherit;
  outline: none;
}

/* --- SCROLLBAR --- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-app);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
}

/* --- GLOBAL LOADING ANIMATION --- */
.app-loader {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border-color);
  border-top-color: var(--primary);
  border-radius: var(--radius-round);
  animation: spin 1s linear infinite;
}

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

/* --- STICKY GLASS HEADER --- */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--glass-shadow);
  transition: background var(--transition-normal), border-color var(--transition-normal);
}

.header-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.4rem;
  letter-spacing: -0.5px;
}

.logo-icon {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.25rem;
  box-shadow: 0 0 15px rgba(99, 102, 241, 0.4);
}

.logo-text {
  background: linear-gradient(to right, var(--text-main), var(--text-muted));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-menu {
  display: flex;
  gap: 32px;
}

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast), transform var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
  transform: translateY(-1px);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.theme-toggle {
  cursor: pointer;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--border-color);
  color: var(--primary);
}

.sun-icon { display: none; }
body.light-theme .sun-icon { display: block; }
body.light-theme .moon-icon { display: none; }
body.dark-theme .moon-icon { display: block; }

.login-btn {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff !important;
  font-weight: 600;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 15px var(--primary-glow);
  transition: var(--transition-fast);
  cursor: pointer;
}

.login-btn:hover {
  opacity: 0.95;
  transform: translateY(-1px);
}

.user-profile-trigger {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-round);
  border: 2px solid var(--primary);
  background: var(--border-color);
}

.logout-btn {
  color: var(--error);
  cursor: pointer;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* --- GLASS CARD STYLING --- */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--glass-shadow);
  transition: border-color var(--transition-fast), transform var(--transition-fast), background var(--transition-fast);
}

.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-focus);
}

/* --- TOAST NOTIFICATIONS --- */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 12px;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  min-width: 300px;
  max-width: 400px;
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  box-shadow: var(--glass-shadow);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  animation: slideInRight var(--transition-fast) forwards;
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--error); }
.toast.info { border-left-color: var(--info); }

.toast-message {
  font-size: 0.9rem;
  font-weight: 500;
}

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

/* --- LANDING VIEW --- */
.landing-hero {
  position: relative;
  max-width: 1280px;
  margin: 0 auto;
  padding: 80px 24px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 48px;
}

.hero-content h1 {
  font-size: 3.5rem;
  line-height: 1.15;
  font-weight: 800;
  margin-bottom: 24px;
  letter-spacing: -1.5px;
}

.text-gradient {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 40px;
}

.hero-actions-group {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  font-weight: 600;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 20px var(--primary-glow);
  cursor: pointer;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-primary:hover {
  transform: translateY(-2px);
  opacity: 0.95;
}

.btn-secondary {
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  font-weight: 600;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-secondary:hover {
  background: var(--border-color);
  transform: translateY(-2px);
}

.hero-illustration {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-illustration img {
  width: 100%;
  max-width: 480px;
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);
  border: 1px solid var(--border-color);
}

.stats-bar {
  display: flex;
  gap: 32px;
  margin-top: 48px;
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
}

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

/* Feature grid */
.section-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 60px 24px;
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 48px;
}

.section-header h2 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.feature-card i {
  color: var(--primary);
  background: var(--primary-glow);
  padding: 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  display: inline-block;
}

.feature-card h3 {
  margin-bottom: 12px;
  font-size: 1.25rem;
}

.feature-card p {
  color: var(--text-muted);
  line-height: 1.5;
  font-size: 0.95rem;
}

/* Portal view */
.auth-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  max-width: 1000px;
  margin: 40px auto;
  gap: 40px;
}

.auth-form-card {
  padding: 32px;
}

.form-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 24px;
}

.form-group {
  margin-bottom: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
}

.form-input {
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

body.light-theme .form-input {
  background: rgba(255, 255, 255, 0.4);
}

.form-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 10px var(--primary-glow);
}

.form-select {
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.95rem;
  cursor: pointer;
}

body.light-theme .form-select {
  background: rgba(255, 255, 255, 0.4);
}

/* --- STUDENT VIEW --- */
.student-dashboard-layout {
  max-width: 1280px;
  margin: 0 auto;
  padding: 40px 24px;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 32px;
}

.dashboard-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}

.stat-box {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
}

.stat-box-icon {
  background: var(--primary-glow);
  color: var(--primary);
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* --- SIDEBAR MENU --- */
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
  z-index: 990;
  opacity: 0;
  visibility: hidden;
  transition: all 0.25s ease;
}

.sidebar-overlay.active {
  opacity: 1;
  visibility: visible;
}

.app-sidebar {
  position: fixed;
  top: 0;
  bottom: 0;
  right: -300px;
  width: 280px;
  background: var(--bg-card);
  border-left: 1px solid var(--border-color);
  z-index: 995;
  display: flex;
  flex-direction: column;
  box-shadow: -5px 10px 40px rgba(0,0,0,0.3);
  transition: right 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow-y: auto;
}

.app-sidebar.active {
  right: 0;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 4px;
  border-radius: 50%;
  transition: var(--transition-fast);
}

.sidebar-close-btn:hover {
  color: var(--text-main);
  background: rgba(255,255,255,0.05);
}

.sidebar-menu-list {
  display: flex;
  flex-direction: column;
  padding: 16px 12px;
  gap: 6px;
  flex: 1;
}

.sidebar-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: var(--transition-fast);
}

.sidebar-nav-item:hover, .sidebar-nav-item.active {
  background: var(--primary-glow);
  color: var(--primary);
}

.sidebar-footer {
  padding: 20px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sidebar-toggle-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-fast);
  margin-inline-end: 8px;
}

.sidebar-toggle-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.stat-box-val {
  font-size: 1.5rem;
  font-weight: 700;
}

.stat-box-lbl {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.dashboard-section-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.courses-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

/* ─── Premium Bakalorya Course Card (Inspired by Screenshot) ──────────────── */
.course-card, .bakalorya-course-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 18px;
  overflow: hidden;
  height: 100%;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.3s;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
  position: relative;
}

.course-card:hover, .bakalorya-course-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.12);
  border-color: var(--primary);
}

.course-card.banned-card {
  border: 1px solid var(--error) !important;
  opacity: 0.8;
}

/* Image Banner */
.course-img-wrapper {
  position: relative;
  height: 180px;
  width: 100%;
  overflow: hidden;
  background: var(--bg-app);
}

.course-img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.course-card:hover .course-img-wrapper img,
.bakalorya-course-card:hover .course-img-wrapper img {
  transform: scale(1.06);
}

/* Category Pill Badge (Top Right) */
.course-category-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: #2563eb;
  color: #ffffff;
  padding: 5px 14px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 800;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
  z-index: 2;
  white-space: nowrap;
}

/* Ribbon Bookmark Flag Badge (Top Left - e.g. 2ث / 3ث / BAC) */
.course-ribbon-badge {
  position: absolute;
  top: 0;
  left: 16px;
  background: #451a03;
  color: #ffffff;
  font-weight: 800;
  font-size: 0.88rem;
  padding: 10px 10px 14px 10px;
  border-radius: 0 0 4px 4px;
  z-index: 2;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 82%, 0 100%);
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
  text-align: center;
  min-width: 38px;
  line-height: 1;
}

/* Content Body */
.course-card-content {
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  gap: 10px;
}

/* Instructor Row */
.course-instructor-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 2px;
}

.course-instructor-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid #3b82f6;
  background: var(--bg-card);
}

.course-instructor-name {
  font-weight: 800;
  font-size: 0.95rem;
  color: var(--text-color);
}

/* Title & Description */
.course-card-title {
  font-size: 1.05rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--text-color);
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-card-desc {
  color: var(--text-muted);
  font-size: 0.84rem;
  line-height: 1.5;
  margin: 0;
  flex-grow: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Card Footer Bar */
.course-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  gap: 8px;
}

.course-tag-subject {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  color: var(--text-muted);
  font-size: 0.82rem;
}

.course-price-pill {
  background: #10b981;
  color: #ffffff;
  padding: 6px 18px;
  border-radius: 20px;
  font-weight: 800;
  font-size: 0.85rem;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s, background 0.2s;
  border: none;
  cursor: pointer;
}

.course-price-pill:hover {
  background: #059669;
  transform: scale(1.04);
}

.course-progress-bar-wrapper {
  margin-bottom: 16px;
}

.course-progress-bar {
  background: var(--border-color);
  height: 6px;
  border-radius: 3px;
  overflow: hidden;
}

.course-progress-fill {
  background: linear-gradient(to right, var(--primary), var(--secondary));
  height: 100%;
}

.course-progress-text {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.course-teacher-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
}

.teacher-profile {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 500;
}

.teacher-avatar {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-round);
}

.schedule-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.session-card {
  padding: 16px;
}

.session-header-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 8px;
}

.session-tag {
  background: var(--accent-glow);
  color: var(--accent);
  border: 1px solid rgba(245, 158, 11, 0.3);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
  text-transform: uppercase;
}

.session-tag.live {
  background: var(--error-glow);
  color: var(--error);
  border-color: rgba(239, 68, 68, 0.3);
  animation: pulse-border 1.5s infinite;
}

@keyframes pulse-border {
  0% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.4); }
  70% { box-shadow: 0 0 0 6px rgba(239, 68, 68, 0); }
  100% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0); }
}

.session-title {
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.3;
}

.session-time {
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
}

.session-action {
  margin-top: 14px;
  width: 100%;
  text-align: center;
  padding: 8px;
  font-size: 0.85rem;
}

/* --- COURSE PLAYER VIEW --- */
.course-player-container {
  display: grid;
  grid-template-columns: 2.3fr 1.2fr;
  height: calc(100vh - 73px);
  overflow: hidden;
}

.player-main-area {
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  border-right: 1px solid var(--border-color);
}

.video-container {
  position: relative;
  background: #000000;
  aspect-ratio: 16/9;
  width: 100%;
}

.video-container video, .video-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.video-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  gap: 16px;
  height: 100%;
}

.player-details-card {
  padding: 24px;
}

.player-details-header {
  margin-bottom: 20px;
}

.player-course-title {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.player-lesson-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 12px;
}

.tabs-header {
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 10px 18px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.92rem;
  cursor: pointer;
  position: relative;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: none;
  outline: none;
}

.tab-btn:hover {
  color: var(--primary);
  background: rgba(99, 102, 241, 0.08);
  transform: translateY(-1px);
}

.tab-btn.active {
  color: var(--primary);
  background: rgba(99, 102, 241, 0.12);
  font-weight: 700;
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--primary);
  border-radius: 3px 3px 0 0;
  box-shadow: 0 0 8px var(--primary);
}

.tab-content-pane {
  display: none;
  line-height: 1.5;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.tab-content-pane.active {
  display: block;
}

.sidebar-curriculum {
  overflow-y: auto;
  padding: 24px;
  background: rgba(10, 10, 15, 0.3);
}

.curriculum-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.chapter-group {
  margin-bottom: 24px;
}

.chapter-header {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}

.lesson-list-items {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.lesson-item-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  cursor: pointer;
  transition: var(--transition-fast);
}

.lesson-item-row:hover, .lesson-item-row.active {
  border-color: var(--primary);
  background: var(--bg-card-hover);
}

.lesson-item-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lesson-checkbox {
  width: 20px;
  height: 20px;
  border-radius: 4px;
  border: 2px solid var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-fast);
}

.lesson-checkbox.checked {
  background: var(--success);
  border-color: var(--success);
  color: #ffffff;
}

.lesson-item-title-meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.lesson-item-title {
  font-size: 0.85rem;
  font-weight: 600;
}

.lesson-item-duration {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* --- VIRTUAL CLASSROOM VIEW --- */
.classroom-layout {
  display: grid;
  grid-template-columns: 3fr 1fr;
  height: calc(100vh - 73px);
  background: #050508;
  overflow: hidden;
}

.classroom-main {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border-color);
  position: relative;
}

.classroom-tabs {
  background: #0a0a0f;
  border-bottom: 1px solid var(--border-color);
  padding: 0 24px;
  display: flex;
  gap: 24px;
}

.classroom-tab {
  padding: 14px 0;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  color: var(--text-muted);
}

.classroom-tab.active {
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
}

.classroom-viewport {
  flex-grow: 1;
  background: #000000;
  position: relative;
}

.video-stream-sim {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.whiteboard-container {
  display: none;
  flex-direction: column;
  width: 100%;
  height: 100%;
}

.whiteboard-container.active {
  display: flex;
}

.whiteboard-tools {
  background: #0d0d14;
  border-bottom: 1px solid var(--border-color);
  padding: 8px 16px;
  display: flex;
  gap: 12px;
  align-items: center;
}

.tool-btn {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  transition: var(--transition-fast);
}

.tool-btn:hover, .tool-btn.active {
  background: var(--border-color);
  color: var(--primary);
}

.tool-color {
  width: 20px;
  height: 20px;
  border-radius: var(--radius-round);
  cursor: pointer;
  border: 2px solid transparent;
}

.tool-color.active {
  border-color: #ffffff;
}

.classroom-canvas {
  flex-grow: 1;
  background: #111116;
  cursor: crosshair;
}

.control-bar {
  background: #0a0a0f;
  border-top: 1px solid var(--border-color);
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.control-icon-btn {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-fast);
}

.control-icon-btn:hover {
  background: var(--border-color);
  color: var(--primary);
}

.control-icon-btn.active {
  background: var(--error-glow);
  color: var(--error);
  border-color: var(--error);
}

.leave-classroom-btn {
  background: var(--error);
  color: #ffffff;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
}

.leave-classroom-btn:hover {
  background: #dc2626;
}

.classroom-chat-sidebar {
  display: flex;
  flex-direction: column;
  background: #0a0a0f;
}

.chat-header {
  padding: 18px 20px;
  border-bottom: 1px solid var(--border-color);
  font-weight: 700;
  font-size: 1rem;
}

.chat-messages {
  flex-grow: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.chat-bubble {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.chat-bubble-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.chat-sender-name {
  font-weight: 600;
}

.chat-sender-role {
  font-size: 0.65rem;
  background: var(--primary-glow);
  color: var(--primary);
  padding: 1px 4px;
  border-radius: 2px;
  margin-left: 4px;
}

.chat-bubble-body {
  background: var(--bg-card);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  line-height: 1.4;
  word-break: break-word;
}

.chat-input-area {
  padding: 16px;
  border-top: 1px solid var(--border-color);
  display: flex;
  gap: 10px;
}

.chat-input-area input {
  flex-grow: 1;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.85rem;
}

.chat-send-btn {
  background: var(--primary);
  color: #ffffff;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

/* --- TEACHER VIEW --- */
.teacher-layout {
  max-width: 1280px;
  margin: 0 auto;
  padding: 40px 24px;
}

.teacher-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
}

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

/* Modals */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.25s forwards;
}

.modal-content {
  background: var(--bg-app);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  width: 100%;
  max-width: 540px;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: slideUp 0.3s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
}

.modal-close-btn {
  cursor: pointer;
  color: var(--text-muted);
  font-size: 1.5rem;
  line-height: 1;
}

.modal-body {
  padding: 24px;
  max-height: 70vh;
  overflow-y: auto;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  background: rgba(0,0,0,0.1);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

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

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

/* Interactive Quick Poll Widget inside Classroom */
.classroom-poll-overlay {
  position: absolute;
  bottom: 80px;
  right: 24px;
  width: 320px;
  z-index: 100;
  animation: slideUp var(--transition-fast) forwards;
}

.poll-option-btn {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-top: 10px;
  text-align: left;
  cursor: pointer;
  transition: var(--transition-fast);
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
}

.poll-option-btn:hover {
  border-color: var(--primary);
  background: var(--bg-card-hover);
}

.poll-results-bar {
  background: var(--border-color);
  height: 4px;
  border-radius: 2px;
  margin-top: 6px;
  overflow: hidden;
}

.poll-results-fill {
  background: var(--primary);
  height: 100%;
  width: 0;
  transition: width 0.8s ease;
}

/* Dynamic whiteboard active styles */
.whiteboard-active-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: var(--radius-round);
  background: var(--success);
  margin-right: 6px;
}