/* ====================================================================
   FACULTY LMS - MOODLE BOOST MODERN THEME
   Vanilla CSS with Rich Design System, Animations & Accessibility
   ==================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Outfit:wght@400;500;600;700&display=swap');

:root {
  /* Color Palette */
  --primary: #0f4c81;
  --primary-hover: #0b3860;
  --primary-light: #e8f0fe;
  --primary-glow: rgba(15, 76, 129, 0.15);
  
  --accent: #ff7043;
  --accent-light: #fff3e0;
  
  --success: #10b981;
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;
  
  --warning: #f59e0b;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;
  
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  
  --info: #3b82f6;
  --info-bg: #eff6ff;
  
  /* Neutral Palette (Light Mode Default) */
  --bg-body: #f4f6f9;
  --bg-surface: #ffffff;
  --bg-surface-alt: #f8fafc;
  --bg-card: #ffffff;
  
  --border-color: #e2e8f0;
  --border-focus: #3b82f6;
  
  --text-main: #1e293b;
  --text-muted: #64748b;
  --text-inverse: #ffffff;
  
  /* Shadows & Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.06);
  
  /* Dimensions & Spacing */
  --header-height: 64px;
  --sidebar-width: 270px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Outfit', sans-serif;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-body: #0b0f17;
  --bg-surface: #151b26;
  --bg-surface-alt: #1a2233;
  --bg-card: #151b26;
  --border-color: #232e42;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --primary-light: rgba(15, 76, 129, 0.3);
  --shadow-card: 0 4px 14px rgba(0, 0, 0, 0.4);
}

/* ====================================================================
   BASE & RESET
   ==================================================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.5;
  font-size: 14.5px;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.25;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}
a:hover {
  text-decoration: underline;
}

/* ====================================================================
   LAYOUT: TOP NAVBAR
   ==================================================================== */
#top-navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
}

.nav-left {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.drawer-toggle-btn {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.65rem;
  cursor: pointer;
  color: var(--text-main);
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}
.drawer-toggle-btn:hover {
  background: var(--bg-surface-alt);
  color: var(--primary);
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}
.brand-logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--primary), #1e3a8a);
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.25rem;
  box-shadow: 0 2px 6px rgba(15, 76, 129, 0.35);
}
.brand-titles {
  display: flex;
  flex-direction: column;
}
.brand-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.01em;
}
.brand-subtitle {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Search bar */
.nav-search-container {
  position: relative;
  width: 280px;
}
.nav-search-input {
  width: 100%;
  padding: 0.45rem 0.9rem 0.45rem 2.2rem;
  font-size: 0.85rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  background: var(--bg-surface-alt);
  color: var(--text-main);
  outline: none;
  transition: var(--transition);
}
.nav-search-input:focus {
  border-color: var(--primary);
  background: var(--bg-surface);
  box-shadow: 0 0 0 3px var(--primary-glow);
}
.nav-search-icon {
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

/* Quick Demo Role Switcher */
.quick-switcher {
  display: flex;
  align-items: center;
  background: var(--primary-light);
  border: 1px solid rgba(15, 76, 129, 0.2);
  border-radius: var(--radius-full);
  padding: 0.25rem 0.75rem;
  gap: 0.5rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--primary);
}
.quick-switcher select {
  background: transparent;
  border: none;
  font-weight: 700;
  color: var(--primary);
  cursor: pointer;
  outline: none;
  font-size: 0.8rem;
}

/* User Actions */
.nav-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.nav-action-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  position: relative;
  font-size: 1.15rem;
  cursor: pointer;
  padding: 0.45rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}
.nav-action-btn:hover {
  color: var(--primary);
  background: var(--bg-surface-alt);
}
.badge-count {
  position: absolute;
  top: -2px;
  right: -2px;
  background: var(--danger);
  color: white;
  font-size: 0.65rem;
  font-weight: 800;
  padding: 0.15rem 0.35rem;
  border-radius: var(--radius-full);
  line-height: 1;
}

.user-profile-menu {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  cursor: pointer;
  padding: 0.3rem 0.6rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
}
.user-profile-menu:hover {
  background: var(--bg-surface-alt);
}
.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border-color);
}
.user-info-text {
  display: flex;
  flex-direction: column;
  text-align: left;
}
.user-name {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-main);
  white-space: nowrap;
}
.user-role-badge {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--primary);
  letter-spacing: 0.03em;
}

/* ====================================================================
   SIDEBAR DRAWER
   ==================================================================== */
#app-layout {
  display: flex;
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
}

#left-drawer {
  width: var(--sidebar-width);
  background: var(--bg-surface);
  border-right: 1px solid var(--border-color);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  position: fixed;
  top: var(--header-height);
  bottom: 0;
  left: 0;
  z-index: 900;
  overflow-y: auto;
  transition: transform 0.25s ease-in-out;
}
#left-drawer.collapsed {
  transform: translateX(-100%);
}

.drawer-section-title {
  font-size: 0.7rem;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  padding: 1.25rem 1.25rem 0.5rem;
}

.drawer-nav-list {
  list-style: none;
  padding: 0 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.drawer-nav-item a {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.65rem 0.9rem;
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  transition: var(--transition);
}
.drawer-nav-item a:hover {
  background: var(--bg-surface-alt);
  color: var(--primary);
  text-decoration: none;
}
.drawer-nav-item.active a {
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
}
.drawer-icon {
  font-size: 1.15rem;
  width: 22px;
  text-align: center;
}

/* Main Content Wrapper */
#main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 2rem;
  transition: margin-left 0.25s ease-in-out;
  max-width: 1400px;
  width: 100%;
}
#main-content.expanded {
  margin-left: 0;
}

/* ====================================================================
   BREADCRUMBS & PAGE HEADER
   ==================================================================== */
.breadcrumb-trail {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}
.breadcrumb-trail a {
  color: var(--text-muted);
}
.breadcrumb-trail a:hover {
  color: var(--primary);
}
.breadcrumb-sep {
  opacity: 0.5;
}

.page-header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
  gap: 1rem;
}
.page-title {
  font-size: 1.75rem;
  letter-spacing: -0.02em;
}
.page-description {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-top: 0.2rem;
}

/* ====================================================================
   BUTTONS & BADGES
   ==================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  padding: 0.55rem 1.1rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none !important;
}
.btn-primary {
  background: var(--primary);
  color: white;
}
.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: 0 3px 8px var(--primary-glow);
}
.btn-outline {
  background: var(--bg-surface);
  border-color: var(--border-color);
  color: var(--text-main);
}
.btn-outline:hover {
  background: var(--bg-surface-alt);
  border-color: var(--primary);
  color: var(--primary);
}
.btn-success {
  background: var(--success);
  color: white;
}
.btn-danger {
  background: var(--danger);
  color: white;
}
.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
  border-radius: var(--radius-sm);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.badge-success {
  background: var(--success-bg);
  color: #065f46;
  border: 1px solid var(--success-border);
}
.badge-warning {
  background: var(--warning-bg);
  color: #92400e;
  border: 1px solid var(--warning-border);
}
.badge-danger {
  background: var(--danger-bg);
  color: #991b1b;
  border: 1px solid var(--danger-border);
}
.badge-info {
  background: var(--info-bg);
  color: #1e40af;
  border: 1px solid #bfdbfe;
}
.badge-primary {
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(15, 76, 129, 0.2);
}

/* ====================================================================
   DASHBOARD STATS & CARDS
   ==================================================================== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2rem;
}
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}
.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}
.stat-value {
  font-size: 1.6rem;
  font-weight: 800;
  font-family: var(--font-display);
  line-height: 1;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 0.25rem;
}

/* Course Grid */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}
.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(15, 76, 129, 0.3);
}
.course-cover-img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  background: #cbd5e1;
}
.course-card-body {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.course-code {
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--primary);
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}
.course-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}
.course-card-desc {
  font-size: 0.83rem;
  color: var(--text-muted);
  line-height: 1.45;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Progress Bar */
.progress-container {
  margin-top: auto;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border-color);
}
.progress-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}
.progress-bar-bg {
  width: 100%;
  height: 8px;
  background: var(--bg-surface-alt);
  border-radius: var(--radius-full);
  overflow: hidden;
  border: 1px solid var(--border-color);
}
.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--success));
  border-radius: var(--radius-full);
  transition: width 0.4s ease;
}

/* ====================================================================
   COURSE VIEW: SECONDARY TABS & MODULES
   ==================================================================== */
.course-tabs-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-bottom: 2px solid var(--border-color);
  margin-bottom: 1.75rem;
  overflow-x: auto;
}
.course-tab-item {
  padding: 0.75rem 1.25rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  white-space: nowrap;
  transition: var(--transition);
}
.course-tab-item:hover {
  color: var(--primary);
}
.course-tab-item.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* Module Section */
.course-module-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  margin-bottom: 1.5rem;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.module-header {
  padding: 1.25rem 1.5rem;
  background: var(--bg-surface-alt);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}
.module-title-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.module-chevron {
  transition: transform 0.2s ease;
}
.module-chevron.expanded {
  transform: rotate(90deg);
}
.module-title {
  font-size: 1.05rem;
  font-weight: 700;
}
.module-activities-list {
  padding: 0.5rem 1rem;
  display: flex;
  flex-direction: column;
}

/* Learning Activity Item */
.activity-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
  text-decoration: none !important;
  color: inherit;
  margin: 0.25rem 0;
  border: 1px solid transparent;
}
.activity-row:hover {
  background: var(--bg-surface-alt);
  border-color: var(--border-color);
}
.activity-left {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex: 1;
}
.activity-icon-badge {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}
.activity-icon-badge.video { background: #fee2e2; color: #dc2626; }
.activity-icon-badge.document { background: #e0f2fe; color: #0284c7; }
.activity-icon-badge.assignment { background: #fef3c7; color: #d97706; }
.activity-icon-badge.quiz { background: #dcfce7; color: #16a34a; }
.activity-icon-badge.text { background: #f3e8ff; color: #9333ea; }

.activity-info {
  display: flex;
  flex-direction: column;
}
.activity-name {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-main);
}
.activity-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}
.activity-completion-check {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--border-color);
  color: transparent;
  cursor: pointer;
  transition: var(--transition);
}
.activity-completion-check.completed {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

/* ====================================================================
   VIDEO PLAYER & DOCUMENT VIEWER
   ==================================================================== */

/* 16:9 widescreen responsive container (YouTube-style) */
.video-player-container {
  background: #000;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  margin-bottom: 0;
  position: relative;
}

/* True 16:9 aspect-ratio trick */
.video-player-container.widescreen-16-9 {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 */
  background: #000;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.video-player-container.widescreen-16-9 video,
.video-player-container.widescreen-16-9 iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}
.video-player-container video {
  width: 100%;
  display: block;
}

/* Theater / Wide Mode - full viewport width */
.video-player-container.theater-mode {
  position: relative;
  width: calc(100vw - var(--sidebar-width) - 4rem);
  max-width: 1600px;
  margin-left: calc(-2rem + 0px);
  border-radius: 0;
}
#main-content.expanded .video-player-container.theater-mode {
  width: calc(100vw - 4rem);
}

/* Enhanced YouTube-style Toolbar */
.video-enhanced-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  background: var(--bg-surface-alt);
  border: 1px solid var(--border-color);
  border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  padding: 0.55rem 0.9rem;
  margin-bottom: 1rem;
}
.toolbar-left, .toolbar-right {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}

/* Speed selector group */
.speed-selector-group {
  display: flex;
  align-items: center;
  gap: 0.2rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 0.15rem 0.4rem;
}
.speed-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.73rem;
  font-weight: 700;
  color: var(--text-muted);
  padding: 0.2rem 0.45rem;
  border-radius: var(--radius-full);
  transition: var(--transition);
  font-family: var(--font-sans);
}
.speed-btn:hover {
  color: var(--primary);
  background: var(--primary-light);
}
.speed-btn.active {
  background: var(--primary);
  color: white;
}

/* Extra small button */
.btn-xs {
  padding: 0.3rem 0.65rem;
  font-size: 0.73rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

/* Video Progress Tracker */
.video-progress-tracker {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.pdf-viewer-frame {
  width: 100%;
  height: 650px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  background: white;
}

/* Drawer backdrop for mobile */
#drawer-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  z-index: 850;
  backdrop-filter: blur(2px);
  transition: opacity 0.2s ease;
  opacity: 0;
}
#drawer-backdrop.active {
  display: block;
  opacity: 1;
}

/* ====================================================================
   RESPONSIVE: TABLET & MOBILE
   ==================================================================== */

@media (max-width: 900px) {
  /* Sidebar becomes an overlay drawer */
  #left-drawer {
    transform: translateX(-100%);
    z-index: 950;
    box-shadow: none;
  }
  #left-drawer.mobile-open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }

  /* Main content takes full width */
  #main-content {
    margin-left: 0 !important;
    padding: 1rem;
  }

  /* Navbar: hide brand text on very small screens */
  .brand-titles {
    display: none;
  }
  .nav-search-container {
    width: 160px;
  }
  .user-info-text {
    display: none;
  }

  /* Theater mode uses full width on mobile */
  .video-player-container.theater-mode {
    width: 100%;
    margin-left: 0;
  }

  /* Toolbar wraps nicely on mobile */
  .video-enhanced-toolbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.6rem;
  }
  .speed-selector-group {
    flex-wrap: wrap;
  }
  .toolbar-left, .toolbar-right {
    width: 100%;
    justify-content: flex-start;
  }

  /* Lesson nav footer stacks */
  .lesson-nav-footer {
    flex-direction: column;
    align-items: stretch;
    text-align: center;
  }
  .lesson-nav-footer > div {
    text-align: center;
  }

  /* Course tabs wrap */
  .course-tabs-nav {
    overflow-x: auto;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
  }

  /* Modal takes full width */
  .modal-dialog {
    max-width: 100% !important;
    margin: 0.5rem;
    border-radius: var(--radius-lg);
  }
  #modal-overlay {
    align-items: flex-end;
  }

  /* Course cards single column */
  .courses-grid {
    grid-template-columns: 1fr !important;
  }

  /* Stats row wraps */
  .stats-grid {
    grid-template-columns: 1fr 1fr !important;
  }

  /* Page header stacks */
  .page-header-container {
    flex-direction: column !important;
    align-items: flex-start !important;
  }

  /* Video progress tracker stacks */
  .video-progress-tracker {
    flex-direction: column;
    align-items: flex-start;
  }
  .video-progress-tracker > div:last-child {
    width: 100%;
  }
  .video-progress-tracker .progress-bar-bg {
    width: 100%;
  }
}

@media (max-width: 600px) {
  /* Very small phones */
  #top-navbar {
    padding: 0 0.75rem;
  }
  #main-content {
    padding: 0.75rem;
  }
  .nav-search-container {
    width: 110px;
  }
  .nav-right {
    gap: 0.4rem;
  }
  .stats-grid {
    grid-template-columns: 1fr !important;
  }
  .speed-selector-group {
    display: none;  /* hide speed on very small – too cramped */
  }
  .lesson-header-card {
    flex-direction: column;
    align-items: flex-start;
  }
  #lesson-complete-toggle-btn {
    width: 100%;
  }
  .modal-dialog {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    margin: 0;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
  }
}


/* ====================================================================
   GRADEBOOK SPREADSHEET TABLE
   ==================================================================== */
.gradebook-table-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  box-shadow: var(--shadow-sm);
  margin-bottom: 2rem;
}
.gradebook-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.84rem;
  text-align: left;
}
.gradebook-table th {
  background: var(--bg-surface-alt);
  padding: 0.85rem 1rem;
  font-weight: 700;
  border-bottom: 2px solid var(--border-color);
  white-space: nowrap;
}
.gradebook-table td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-color);
  vertical-align: middle;
}
.gradebook-table tr:hover td {
  background: var(--bg-surface-alt);
}
.letter-badge {
  display: inline-block;
  font-weight: 800;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
}
.letter-A { background: #dcfce7; color: #15803d; }
.letter-B { background: #e0f2fe; color: #0369a1; }
.letter-C { background: #fef3c7; color: #b45309; }
.letter-D { background: #ffedd5; color: #c2410c; }
.letter-F { background: #fee2e2; color: #b91c1c; }

/* ====================================================================
   QUIZ RUNNER INTERFACE
   ==================================================================== */
.quiz-header-bar {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  position: sticky;
  top: calc(var(--header-height) + 10px);
  z-index: 100;
  box-shadow: var(--shadow-md);
}
.quiz-timer-box {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--danger);
  font-family: monospace;
}
.quiz-question-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  margin-bottom: 1.5rem;
}
.quiz-option-label {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin: 0.5rem 0;
  cursor: pointer;
  transition: var(--transition);
}
.quiz-option-label:hover {
  background: var(--bg-surface-alt);
  border-color: var(--primary);
}
.quiz-option-label input {
  margin-top: 0.2rem;
  accent-color: var(--primary);
}

/* ====================================================================
   CERTIFICATE MODAL & PRINT STYLING
   ==================================================================== */
.certificate-frame {
  background: #fdfbf7;
  border: 10px double #b8860b;
  border-radius: var(--radius-md);
  padding: 3rem 2.5rem;
  text-align: center;
  position: relative;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
  max-width: 780px;
  margin: 0 auto;
}
.certificate-seal {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: linear-gradient(135deg, #d4af37, #aa771c);
  color: white;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 1.5rem auto;
  box-shadow: 0 4px 10px rgba(184, 134, 11, 0.4);
  font-weight: 800;
  font-size: 0.75rem;
  text-transform: uppercase;
}

/* Modal Dialog */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  padding: 1.5rem;
}
.modal-dialog {
  background: var(--bg-surface);
  border-radius: var(--radius-lg);
  max-width: 650px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  animation: modalPop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}
@keyframes modalPop {
  from { opacity: 0; transform: scale(0.96); }
  to { opacity: 1; transform: scale(1); }
}
.modal-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.modal-body {
  padding: 1.5rem;
}
.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
  background: var(--bg-surface-alt);
}

/* Toast Notification */
#toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  z-index: 3000;
}
.toast {
  background: var(--text-main);
  color: var(--bg-surface);
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.2s ease-out;
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(15px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Responsive adjustments */
@media (max-width: 900px) {
  #left-drawer {
    transform: translateX(-100%);
  }
  #left-drawer.mobile-open {
    transform: translateX(0);
  }
  #main-content {
    margin-left: 0 !important;
    padding: 1.25rem;
  }
  .nav-search-container {
    display: none;
  }
}

/* ====================================================================
   TRUE / FALSE INTERACTIVE EXAM CARDS
   ==================================================================== */
.quiz-tf-card {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1.85rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  background: var(--bg-surface-alt);
  transition: all 0.2s ease;
  user-select: none;
}
.quiz-tf-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.quiz-tf-card .tf-icon {
  font-size: 1.25rem;
  font-weight: 800;
}
.quiz-tf-card .tf-text {
  font-size: 1rem;
  font-weight: 700;
}
.quiz-tf-card.selected-true {
  border-color: #10b981 !important;
  background: rgba(16, 185, 129, 0.15) !important;
  color: #059669 !important;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.25);
}
.quiz-tf-card.selected-false {
  border-color: #ef4444 !important;
  background: rgba(239, 68, 68, 0.15) !important;
  color: #dc2626 !important;
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.25);
}