@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Fira+Code:wght@400;500&display=swap');

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  
  --navy-950: #060d1a;
  --navy-900: #0b1528;
  --navy-850: #101e38;
  --navy-800: #162749;
  --navy-700: #1e355f;
  
  --teal: #0d9488;
  --teal-light: #f0fdfa;
  --teal-border: #99f6e4;
  
  --emerald: #10b981;
  --emerald-light: #ecfdf5;
  --emerald-border: #a7f3d0;
  --emerald-dark: #065f46;
  
  --amber: #f59e0b;
  --amber-light: #fffbeb;
  --amber-border: #fde68a;
  --amber-dark: #92400e;
  
  --rose: #ef4444;
  --rose-light: #fef2f2;
  --rose-border: #fecaca;
  --rose-dark: #991b1b;
  
  --ink-900: #0f172a;
  --ink-800: #1e293b;
  --ink-700: #334155;
  --ink-600: #475569;
  --ink-500: #64748b;
  --ink-400: #94a3b8;
  --ink-300: #cbd5e1;
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --border-light: #e2e8f0;
  --border-subtle: #edf2f7;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
  
  --font-main: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-code: 'Fira Code', Consolas, monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-main);
  color: var(--ink-800);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  -webkit-font-smoothing: antialiased;
}

/* ============================================================
   SIDEBAR NAVIGATION
   ============================================================ */
aside {
  width: 270px;
  background: linear-gradient(180deg, var(--navy-950) 0%, var(--navy-900) 100%);
  color: white;
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  flex: none;
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 50;
  transition: transform 0.3s ease;
}

.brand {
  font-size: 19px;
  font-weight: 700;
  color: #ffffff;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 28px;
  padding: 4px 6px;
  border-radius: var(--radius-sm);
  transition: opacity 0.2s;
}

.brand:hover {
  opacity: 0.9;
}

.brand b, .brand-mark {
  display: inline-grid;
  place-items: center;
  background: linear-gradient(135deg, #38bdf8 0%, #2563eb 100%);
  color: white;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  font-size: 18px;
  font-weight: 800;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.35);
}

.aside-course-meta {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: 14px 14px;
  margin-bottom: 24px;
}

.eyebrow {
  font-size: 10.5px;
  letter-spacing: 1.2px;
  font-weight: 700;
  text-transform: uppercase;
  color: #38bdf8;
  margin-bottom: 4px;
}

#course-title {
  font-size: 17px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 4px;
  line-height: 1.3;
}

.course-sub {
  color: var(--ink-400);
  font-size: 12.5px;
  line-height: 1.4;
}

.course-progress-mini {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.progress-label-row {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--ink-400);
  margin-bottom: 5px;
}

.progress-track {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 99px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #38bdf8, #10b981);
  border-radius: 99px;
  transition: width 0.4s ease;
  width: 0%;
}

nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

nav button {
  border: 1px solid transparent;
  background: transparent;
  color: #94a3b8;
  text-align: left;
  padding: 11px 14px;
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  width: 100%;
}

nav button svg, nav button .nav-icon {
  font-size: 15px;
  width: 18px;
  text-align: center;
  opacity: 0.8;
}

nav button:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
  transform: translateX(2px);
}

nav button.on {
  background: linear-gradient(90deg, var(--navy-800) 0%, var(--navy-700) 100%);
  color: #ffffff;
  border: 1px solid rgba(56, 189, 248, 0.3);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

nav button.on .nav-icon {
  opacity: 1;
  color: #38bdf8;
}

.aside-footer {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.status-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #64748b;
  font-size: 11.5px;
  font-weight: 500;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 8px #10b981;
}

/* ============================================================
   MAIN CONTENT AREA & TOPBAR
   ============================================================ */
main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

header.topbar {
  height: 64px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  padding: 0 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 40;
}

.breadcrumbs {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-500);
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumbs a {
  color: var(--ink-500);
  text-decoration: none;
  transition: color 0.2s;
}

.breadcrumbs a:hover {
  color: var(--primary);
}

.breadcrumbs .sep {
  color: var(--ink-300);
}

#crumb {
  color: var(--ink-900);
  font-weight: 700;
}

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

.avatar {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  color: var(--primary);
  border: 1px solid var(--primary-border);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
}

.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 16px;
  cursor: pointer;
  color: var(--ink-700);
}

#app {
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 36px 40px;
  flex: 1;
}

footer {
  background: white;
  border-top: 1px solid var(--border-light);
  padding: 16px 40px;
  font-size: 12.5px;
  color: var(--ink-500);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ============================================================
   HERO & CARDS
   ============================================================ */
.hero {
  background: linear-gradient(130deg, var(--navy-950) 0%, var(--navy-850) 55%, #134e4a 100%);
  color: white;
  padding: 42px 40px;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  margin-bottom: 28px;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  top: -60px;
  right: -60px;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero .eyebrow {
  color: #38bdf8;
  margin-bottom: 10px;
}

.hero h1 {
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.hero p {
  color: #cbd5e1;
  font-size: 15.5px;
  max-width: 620px;
  line-height: 1.6;
  margin-bottom: 24px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 24px 0 32px;
}

.stat-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 20px 22px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}

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

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 22px;
  flex: none;
}

.stat-icon.blue { background: #eff6ff; color: #2563eb; }
.stat-icon.teal { background: #f0fdfa; color: #0d9488; }
.stat-icon.amber { background: #fffbeb; color: #d97706; }

.stat-info strong {
  display: block;
  font-size: 24px;
  font-weight: 800;
  color: var(--ink-900);
  line-height: 1.2;
}

.stat-info span {
  font-size: 13px;
  color: var(--ink-500);
  font-weight: 500;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 16px 0;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.card:hover {
  border-color: #cbd5e1;
}

/* ============================================================
   BUTTONS & BADGES
   ============================================================ */
.btn {
  background: var(--primary);
  color: white;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}

.btn:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.25);
}

.btn:active {
  transform: translateY(0);
}

.btn.alt {
  background: white;
  border: 1px solid var(--border-light);
  color: var(--ink-700);
  box-shadow: var(--shadow-sm);
}

.btn.alt:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
  color: var(--ink-900);
}

.btn.success {
  background: var(--emerald);
  box-shadow: 0 2px 4px rgba(16, 185, 129, 0.2);
}

.btn.success:hover {
  background: #059669;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  padding: 3px 10px;
  border-radius: 99px;
  background: var(--teal-light);
  color: var(--teal);
  border: 1px solid var(--teal-border);
  margin-bottom: 12px;
}

.tag.blue {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary-border);
}

.tag.amber {
  background: var(--amber-light);
  color: var(--amber-dark);
  border-color: var(--amber-border);
}

.tag.rose {
  background: var(--rose-light);
  color: var(--rose-dark);
  border-color: var(--rose-border);
}

.tag.emerald {
  background: var(--emerald-light);
  color: var(--emerald-dark);
  border-color: var(--emerald-border);
}

/* ============================================================
   LEARNING PATH / ROADMAP (OVERVIEW VIEW)
   ============================================================ */
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin: 32px 0 16px;
}

.section-head h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink-900);
}

.roadmap-grid {
  display: grid;
  gap: 12px;
}

.lesson-row-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  display: flex;
  align-items: center;
  gap: 18px;
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.lesson-row-card:hover {
  border-color: var(--primary);
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.lesson-num {
  width: 40px;
  height: 40px;
  background: #eff6ff;
  color: var(--primary);
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 15px;
  flex: none;
  transition: all 0.2s;
}

.lesson-row-card.is-completed .lesson-num {
  background: #ecfdf5;
  color: var(--emerald);
}

.lesson-row-info {
  flex: 1;
  min-width: 0;
}

.lesson-row-info b {
  display: block;
  font-size: 15.5px;
  color: var(--ink-900);
  margin-bottom: 2px;
}

.lesson-row-info .hint {
  font-size: 12.5px;
  color: var(--ink-500);
}

.lesson-row-action {
  color: var(--ink-400);
  font-size: 18px;
  transition: transform 0.2s, color 0.2s;
}

.lesson-row-card:hover .lesson-row-action {
  color: var(--primary);
  transform: translateX(3px);
}

/* ============================================================
   LESSON READER VIEW
   ============================================================ */
.lesson-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 24px;
  align-items: start;
}

article.lesson-content {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 36px 40px;
  box-shadow: var(--shadow-sm);
}

article.lesson-content h1 {
  font-size: 26px;
  font-weight: 800;
  color: var(--ink-900);
  line-height: 1.3;
  margin-bottom: 20px;
}

article.lesson-content h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink-900);
  margin: 30px 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
}

article.lesson-content p, 
article.lesson-content ul, 
article.lesson-content ol {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-700);
  margin-bottom: 16px;
}

article.lesson-content ul, 
article.lesson-content ol {
  padding-left: 24px;
}

article.lesson-content li {
  margin-bottom: 8px;
}

article.lesson-content .worked {
  background: #f8fafc;
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 18px 22px;
  margin: 22px 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-800);
}

article.lesson-content .worked b {
  color: var(--primary);
  display: block;
  margin-bottom: 6px;
}

article.lesson-content .check {
  background: var(--teal-light);
  border: 1px solid var(--teal-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin: 24px 0;
}

article.lesson-content .check summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--teal);
  font-size: 14.5px;
  outline: none;
  user-select: none;
}

article.lesson-content .check summary:hover {
  color: #0f766e;
}

article.lesson-content .check p {
  margin-top: 12px;
  margin-bottom: 0;
  color: var(--ink-800);
  font-size: 14px;
}

.lesson-nav-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
  gap: 12px;
}

.lesson-sidebar {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 20px;
  position: sticky;
  top: 88px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.lesson-sidebar-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-900);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.lesson-toc-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.lesson-toc-item {
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 9px 12px;
  text-align: left;
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-600);
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  transition: all 0.2s;
  width: 100%;
}

.lesson-toc-item:hover {
  background: #f1f5f9;
  color: var(--ink-900);
}

.lesson-toc-item.active {
  background: var(--primary-light);
  border-color: var(--primary-border);
  color: var(--primary);
  font-weight: 700;
}

.lesson-toc-badge {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--ink-300);
  color: white;
  font-size: 10.5px;
  font-weight: 700;
  display: grid;
  place-items: center;
  flex: none;
}

.lesson-toc-item.active .lesson-toc-badge {
  background: var(--primary);
}

.lesson-toc-item.completed .lesson-toc-badge {
  background: var(--emerald);
}

/* ============================================================
   MCQ QUIZ VIEW
   ============================================================ */
.quiz-header-banner {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 24px 30px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.score-banner {
  background: linear-gradient(135deg, #eff6ff 0%, #ecfdf5 100%);
  border: 1px solid var(--emerald-border);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  animation: fadeIn 0.4s ease;
}

.score-banner-text h2 {
  font-size: 26px;
  font-weight: 800;
  color: var(--ink-900);
  margin-bottom: 4px;
}

.score-banner-text p {
  color: var(--ink-600);
  font-size: 14.5px;
}

.q {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s;
}

.q h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-900);
  margin: 10px 0 18px;
  line-height: 1.5;
}

.opt {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin: 8px 0;
  cursor: pointer;
  background: white;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  user-select: none;
}

.opt:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
}

.opt input[type="radio"] {
  accent-color: var(--primary);
  width: 17px;
  height: 17px;
  cursor: pointer;
}

.opt span {
  font-size: 14.5px;
  color: var(--ink-800);
  flex: 1;
}

.opt.is-correct {
  background: var(--emerald-light) !important;
  border-color: var(--emerald-border) !important;
  color: var(--emerald-dark) !important;
  font-weight: 600;
}

.opt.is-wrong {
  background: var(--rose-light) !important;
  border-color: var(--rose-border) !important;
  color: var(--rose-dark) !important;
}

.feedback {
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  margin-top: 14px;
  font-size: 14px;
  line-height: 1.6;
  animation: fadeIn 0.3s ease;
}

.feedback.ok {
  background: var(--emerald-light);
  border: 1px solid var(--emerald-border);
  color: var(--emerald-dark);
}

.feedback.no {
  background: var(--rose-light);
  border: 1px solid var(--rose-border);
  color: var(--rose-dark);
}

/* ============================================================
   NUMERICAL PRACTICE VIEW
   ============================================================ */
.guide-card {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin-bottom: 24px;
  font-size: 13.5px;
  color: #166534;
}

.guide-card b {
  display: block;
  margin-bottom: 4px;
  font-size: 14px;
}

.num-form {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 14px 0 8px;
  flex-wrap: wrap;
}

.input {
  padding: 11px 16px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-family: var(--font-code);
  font-size: 14px;
  color: var(--ink-900);
  width: 300px;
  background: white;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s;
}

.input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.input::placeholder {
  font-family: var(--font-main);
  color: var(--ink-400);
}

/* ============================================================
   ASSIGNMENT VIEW
   ============================================================ */
details.assignment-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 0;
  margin: 16px 0;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: all 0.2s;
}

details.assignment-card[open] {
  border-color: var(--primary-border);
  box-shadow: var(--shadow-md);
}

details.assignment-card summary {
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-900);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: white;
  user-select: none;
  transition: background 0.2s;
}

details.assignment-card summary:hover {
  background: #f8fafc;
}

.assignment-body {
  padding: 0 24px 24px;
  border-top: 1px solid var(--border-subtle);
}

.assignment-section {
  margin-top: 18px;
}

.assignment-section-label {
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--ink-500);
  margin-bottom: 6px;
}

.assignment-solution-box {
  background: #f8fafc;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--ink-800);
}

.rubric-list {
  list-style: none;
  padding: 0;
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.rubric-item {
  background: #f1f5f9;
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 13px;
  color: var(--ink-700);
  display: flex;
  align-items: center;
  gap: 8px;
}

.rubric-bullet {
  color: var(--primary);
  font-weight: 700;
}

/* ============================================================
   INSTRUCTOR VIEW
   ============================================================ */
.instructor-guide-content {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  margin-top: 24px;
}

.instructor-guide-content h1, 
.instructor-guide-content h2, 
.instructor-guide-content h3 {
  color: var(--ink-900);
  margin-top: 24px;
  margin-bottom: 12px;
}

.instructor-guide-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 14px;
}

.instructor-guide-content th, 
.instructor-guide-content td {
  padding: 10px 14px;
  border: 1px solid var(--border-light);
  text-align: left;
}

.instructor-guide-content th {
  background: #f8fafc;
  font-weight: 700;
  color: var(--ink-800);
}

/* ============================================================
   COURSE CATALOG (HOME) PAGE
   ============================================================ */
.catalog-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 40px 32px;
}

.catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 24px;
}

.catalog-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.catalog-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-border);
}

.catalog-card h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink-900);
  margin: 8px 0;
}

.catalog-card p {
  color: var(--ink-600);
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 20px;
  flex: 1;
}

.catalog-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  border-top: 1px solid var(--border-subtle);
  margin-top: auto;
}

/* ============================================================
   KATEX & MATH OVERFLOW
   ============================================================ */
.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 8px 0;
  margin: 12px 0 !important;
}

.katex {
  font-size: 1.05em;
  text-rendering: geometricPrecision;
}

/* ============================================================
   ANIMATIONS & UTILITIES
   ============================================================ */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   RESPONSIVE DESIGN
   ============================================================ */
@media (max-width: 900px) {
  body {
    flex-direction: column;
  }
  
  aside {
    width: 100%;
    height: auto;
    position: relative;
    padding: 16px 20px;
  }
  
  .aside-course-meta, .aside-footer {
    display: none;
  }
  
  nav {
    flex-direction: row;
    overflow-x: auto;
    padding-bottom: 4px;
  }
  
  nav button {
    white-space: nowrap;
    padding: 8px 14px;
    font-size: 12.5px;
  }
  
  header.topbar {
    padding: 0 20px;
  }
  
  #app {
    padding: 24px 20px;
  }
  
  .lesson-layout {
    grid-template-columns: 1fr;
  }
  
  .lesson-sidebar {
    position: static;
    max-height: none;
  }
  
}

/* ============================================================
   ENHANCED WEEK & LESSON NAVIGATION SYSTEM
   ============================================================ */

/* Top Week Navigation Card above Lesson Content */
.week-nav-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 18px 22px;
  margin-bottom: 22px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.week-selector-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.week-tabs {
  display: flex;
  gap: 8px;
  background: var(--bg-main);
  padding: 4px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
}

.week-tab-btn {
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-600);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
}

.week-tab-btn:hover {
  color: var(--ink-900);
}

.week-tab-btn.active {
  background: white;
  color: var(--primary);
  border-color: var(--border-light);
  box-shadow: var(--shadow-sm);
  font-weight: 700;
}

.week-badge-pill {
  font-size: 10.5px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 99px;
  background: #f1f5f9;
  color: var(--ink-500);
}

.week-tab-btn.active .week-badge-pill {
  background: var(--primary-light);
  color: var(--primary);
}

.week-badge-pill.done {
  background: var(--emerald-light) !important;
  color: var(--emerald-dark) !important;
}

/* Horizontal Lesson Stepper */
.lesson-stepper {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.stepper-item {
  background: #f8fafc;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  text-align: left;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.stepper-item:hover {
  background: white;
  border-color: var(--primary-border);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.stepper-item.active {
  background: #ffffff;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.15), var(--shadow-sm);
}

.stepper-num {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--ink-300);
  color: white;
  font-size: 11px;
  font-weight: 800;
  display: grid;
  place-items: center;
  flex: none;
  transition: all 0.2s;
}

.stepper-item.active .stepper-num {
  background: var(--primary);
  color: white;
}

.stepper-item.completed .stepper-num {
  background: var(--emerald);
  color: white;
}

.stepper-info {
  flex: 1;
  min-width: 0;
}

.stepper-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-800);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: block;
}

.stepper-item.active .stepper-title {
  color: var(--primary);
  font-weight: 700;
}

.stepper-state {
  font-size: 10.5px;
  color: var(--ink-400);
  display: block;
}

.stepper-item.active .stepper-state {
  color: var(--primary);
  font-weight: 600;
}

.stepper-item.completed .stepper-state {
  color: var(--emerald);
  font-weight: 600;
}

/* Sidebar Week Accordion */
.week-accordion {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  background: white;
  transition: border-color 0.2s;
}

.week-accordion.is-current-week {
  border-color: var(--primary-border);
}

.week-accordion-header {
  padding: 12px 14px;
  background: #f8fafc;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  transition: background 0.2s;
}

.week-accordion-header:hover {
  background: #f1f5f9;
}

.week-accordion-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--ink-900);
  display: flex;
  align-items: center;
  gap: 8px;
}

.week-accordion-chevron {
  font-size: 11px;
  color: var(--ink-400);
  transition: transform 0.2s;
}

.week-accordion.is-open .week-accordion-chevron {
  transform: rotate(180deg);
}

.week-accordion-body {
  display: none;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
}

.week-accordion.is-open .week-accordion-body {
  display: flex;
}

/* Bottom Lesson Nav Actions */
.lesson-nav-bar-enhanced {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: center;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
}

.lesson-nav-btn {
  display: flex;
  flex-direction: column;
  padding: 11px 18px;
  border-radius: var(--radius-sm);
  background: white;
  border: 1px solid var(--border-light);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-sm);
}

.lesson-nav-btn:hover:not(:disabled) {
  border-color: var(--primary);
  background: #f8fafc;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.lesson-nav-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.lesson-nav-dir {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--ink-400);
  display: flex;
  align-items: center;
  gap: 4px;
}

.lesson-nav-btn:hover:not(:disabled) .lesson-nav-dir {
  color: var(--primary);
}

.lesson-nav-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-800);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 2px;
}

.lesson-nav-btn.next {
  text-align: right;
  align-items: flex-end;
}

.lesson-nav-btn.next:hover:not(:disabled) {
  background: #eff6ff;
  border-color: var(--primary-border);
}

.btn-complete-lesson {
  padding: 12px 22px;
  font-weight: 700;
  font-size: 14px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

/* Week Overview Modules */
.week-module-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 28px 30px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.week-module-card:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.week-module-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 20px;
}

.week-module-title-grp h3 {
  font-size: 19px;
  font-weight: 800;
  color: var(--ink-900);
  margin-bottom: 4px;
}

.week-module-title-grp p {
  color: var(--ink-500);
  font-size: 13.5px;
}

.week-progress-box {
  min-width: 180px;
}

.week-module-lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}

.week-module-lesson-pill {
  background: #f8fafc;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.week-module-lesson-pill:hover {
  background: white;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.week-module-lesson-pill.is-done {
  border-color: var(--emerald-border);
  background: #fcfdfd;
}

.keyboard-hint {
  font-size: 11px;
  color: var(--ink-400);
  display: flex;
  align-items: center;
  gap: 6px;
}

.kbd-badge {
  background: #f1f5f9;
  border: 1px solid #cbd5e1;
  border-radius: 4px;
  padding: 2px 6px;
  font-family: var(--font-code);
  font-size: 10px;
  font-weight: 600;
  color: var(--ink-600);
}

@media (max-width: 768px) {
  .lesson-stepper {
    grid-template-columns: repeat(2, 1fr);
  }
  .lesson-nav-bar-enhanced {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .lesson-nav-btn.next {
    text-align: left;
    align-items: flex-start;
  }
  .week-module-lessons-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================================
   AUTHENTICATION & ROSTER MANAGEMENT SYSTEM
   ============================================================ */

/* Topbar Account Pill */
.user-pill-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  background: white;
  border: 1px solid var(--border-light);
  border-radius: 99px;
  padding: 4px 14px 4px 6px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-sm);
}

.user-pill-btn:hover {
  border-color: var(--primary-border);
  background: #f8fafc;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.user-pill-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 14px;
  font-weight: 700;
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  color: var(--primary);
  border: 1px solid var(--primary-border);
}

.user-pill-avatar.instructor {
  background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
  color: var(--rose-dark);
  border-color: var(--rose-border);
}

.user-pill-info {
  display: flex;
  flex-direction: column;
  text-align: left;
  line-height: 1.2;
}

.user-pill-name {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-900);
}

.user-pill-role {
  font-size: 10.5px;
  font-weight: 600;
  color: var(--ink-500);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.user-pill-chevron {
  font-size: 10px;
  color: var(--ink-400);
  margin-left: 2px;
}

/* Modals Overlay & Card */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.65);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fadeIn 0.2s ease;
}

.modal-card {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  max-width: 580px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  border: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  animation: modalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-card.modal-lg {
  max-width: 820px;
}

@keyframes modalPop {
  from { opacity: 0; transform: scale(0.96) translateY(10px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

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

.modal-header h3 {
  font-size: 18px;
  font-weight: 800;
  color: var(--ink-900);
  margin: 0;
}

.modal-close-btn {
  background: transparent;
  border: 0;
  font-size: 20px;
  color: var(--ink-400);
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 6px;
  line-height: 1;
}

.modal-close-btn:hover {
  background: #f1f5f9;
  color: var(--ink-800);
}

.modal-body {
  padding: 24px;
}

.modal-footer {
  padding: 16px 24px;
  background: #f8fafc;
  border-top: 1px solid var(--border-light);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* Auth Tabs & Forms */
.auth-nav-tabs {
  display: flex;
  background: #f1f5f9;
  padding: 4px;
  border-radius: var(--radius-sm);
  margin-bottom: 22px;
  gap: 4px;
}

.auth-nav-tab {
  flex: 1;
  padding: 9px 12px;
  background: transparent;
  border: 0;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-600);
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

.auth-nav-tab.active {
  background: white;
  color: var(--primary);
  font-weight: 700;
  box-shadow: var(--shadow-sm);
}

.auth-field-group {
  margin-bottom: 16px;
}

.auth-field-label {
  display: block;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-800);
  margin-bottom: 6px;
}

.auth-input {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--ink-900);
  transition: all 0.2s;
  box-sizing: border-box;
}

.auth-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.btn-google {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 11px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-800);
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-sm);
  margin-bottom: 14px;
}

.btn-google:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.btn-google svg {
  width: 18px;
  height: 18px;
}

.divider-text {
  display: flex;
  align-items: center;
  text-align: center;
  margin: 18px 0;
  color: var(--ink-400);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.divider-text::before,
.divider-text::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid var(--border-light);
}

.divider-text span {
  padding: 0 12px;
}

/* OTP Code Box */
.otp-display-box {
  background: #f8fafc;
  border: 1px dashed var(--primary-border);
  border-radius: var(--radius-sm);
  padding: 16px;
  text-align: center;
  margin: 16px 0;
}

.otp-code-value {
  font-family: var(--font-code);
  font-size: 26px;
  font-weight: 800;
  letter-spacing: 6px;
  color: var(--primary);
  margin: 6px 0;
}

/* Simulated Email Notification Toast (Floating Popup) */
.simulated-email-toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  max-width: 440px;
  width: calc(100vw - 48px);
  background: white;
  border: 1px solid var(--primary-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  z-index: 2000;
  overflow: hidden;
  animation: slideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.simulated-email-header {
  background: linear-gradient(135deg, var(--navy-950) 0%, var(--navy-850) 100%);
  color: white;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  font-weight: 700;
}

.simulated-email-body {
  padding: 16px 18px;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--ink-800);
}

.simulated-email-meta {
  font-size: 11.5px;
  color: var(--ink-500);
  margin-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 6px;
}

/* Portal Sub-tabs (Roster vs Curriculum Guide) */
.portal-tabs-row {
  display: flex;
  gap: 8px;
  border-bottom: 2px solid var(--border-light);
  margin: 24px 0 20px;
}

.portal-tab-btn {
  padding: 10px 18px;
  background: transparent;
  border: 0;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-500);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
}

.portal-tab-btn:hover {
  color: var(--ink-900);
}

.portal-tab-btn.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* Roster KPI Summary Grid */
.roster-kpis {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 22px;
}

.roster-kpi-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  box-shadow: var(--shadow-sm);
}

.roster-kpi-val {
  font-size: 24px;
  font-weight: 800;
  color: var(--ink-900);
  line-height: 1.1;
  margin-bottom: 4px;
}

.roster-kpi-label {
  font-size: 12px;
  color: var(--ink-500);
  font-weight: 600;
}

/* Roster Action Toolbar */
.roster-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.roster-search-input {
  padding: 9px 14px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  width: 260px;
  background: white;
}

.roster-search-input:focus {
  outline: none;
  border-color: var(--primary);
}

.roster-actions-grp {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* Student Roster Table */
.roster-table-wrapper {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow-x: auto;
}

.roster-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  text-align: left;
}

.roster-table th {
  background: #f8fafc;
  padding: 12px 16px;
  font-weight: 700;
  color: var(--ink-700);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.7px;
  border-bottom: 1px solid var(--border-light);
  white-space: nowrap;
}

.roster-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--ink-800);
  vertical-align: middle;
}

.roster-table tr:hover td {
  background: #fafcff;
}

.roster-student-cell {
  display: flex;
  align-items: center;
  gap: 12px;
}

.student-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  color: var(--primary);
  font-weight: 700;
  display: grid;
  place-items: center;
  font-size: 13.5px;
  flex: none;
}

.student-name-grp b {
  display: block;
  font-size: 14px;
  color: var(--ink-900);
}

.student-name-grp span {
  font-size: 12px;
  color: var(--ink-400);
}

/* Status Badges */
.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 99px;
  text-transform: uppercase;
}

.status-pill.active {
  background: var(--emerald-light);
  color: var(--emerald-dark);
  border: 1px solid var(--emerald-border);
}

.status-pill.invited {
  background: var(--amber-light);
  color: var(--amber-dark);
  border: 1px solid var(--amber-border);
}

.status-pill.dropped {
  background: #f1f5f9;
  color: var(--ink-500);
  border: 1px solid #cbd5e1;
}

/* Roster Action Buttons */
.roster-btn-sm {
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 6px;
  border: 1px solid var(--border-light);
  background: white;
  cursor: pointer;
  color: var(--ink-700);
  transition: all 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.roster-btn-sm:hover {
  background: #f1f5f9;
  color: var(--ink-900);
  border-color: #cbd5e1;
}

.roster-btn-sm.danger:hover {
  background: var(--rose-light);
  color: var(--rose-dark);
  border-color: var(--rose-border);
}

.roster-btn-sm.primary:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary-border);
}

@media (max-width: 900px) {
  .roster-kpis {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ============================================================
   COURSE ENTRY GOOGLE AUTHENTICATION GATE
   ============================================================ */
.auth-gate-container {
  max-width: 780px;
  margin: 12px auto 40px;
  animation: fadeIn 0.3s ease-out;
}

.auth-gate-header {
  text-align: center;
  margin-bottom: 24px;
}

.auth-gate-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: white;
  border: 1px solid var(--border-light);
  padding: 6px 14px;
  border-radius: 99px;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-700);
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
}

.auth-gate-title {
  font-size: 30px;
  font-weight: 800;
  color: var(--ink-900);
  line-height: 1.25;
  letter-spacing: -0.5px;
  margin-bottom: 10px;
}

.auth-gate-desc {
  font-size: 15px;
  color: var(--ink-600);
  line-height: 1.6;
  max-width: 640px;
  margin: 0 auto;
}

/* Highlights Grid */
.auth-gate-course-preview {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 24px;
}

@media (max-width: 640px) {
  .auth-gate-course-preview {
    grid-template-columns: 1fr;
  }
}

.preview-item {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 14px;
  box-shadow: var(--shadow-sm);
}

.preview-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--primary-light);
  color: var(--primary);
  display: grid;
  place-items: center;
  font-size: 18px;
  flex: none;
}

.preview-item b {
  display: block;
  font-size: 13.5px;
  color: var(--ink-900);
  font-weight: 700;
  margin-bottom: 2px;
}

.preview-item span {
  display: block;
  font-size: 12px;
  color: var(--ink-500);
}

/* Main Card */
.auth-gate-main-card {
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
}

.google-auth-box {
  padding: 32px 32px 28px;
  border-bottom: 1px solid var(--border-light);
}

.google-brand-row {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 22px;
}

.google-brand-row h3 {
  font-size: 20px;
  font-weight: 800;
  color: var(--ink-900);
  margin-bottom: 4px;
}

.google-brand-row p {
  font-size: 13px;
  color: var(--ink-500);
  margin: 0;
}

/* Enrolled Accounts List */
.google-accounts-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 20px;
}

.google-account-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  background: #f8fafc;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  width: 100%;
  cursor: pointer;
  text-align: left;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.google-account-btn:hover {
  background: #ffffff;
  border-color: #4285F4;
  box-shadow: 0 4px 12px rgba(66, 133, 244, 0.12);
  transform: translateY(-1px);
}

.google-avatar-circle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4285F4 0%, #1a73e8 100%);
  color: white;
  font-weight: 800;
  font-size: 14px;
  display: grid;
  place-items: center;
  flex: none;
  box-shadow: 0 2px 6px rgba(66, 133, 244, 0.3);
}

.google-account-text {
  flex: 1;
  min-width: 0;
}

.google-account-text .account-name {
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-900);
}

.google-account-text .account-email {
  display: block;
  font-size: 12px;
  color: var(--ink-500);
}

.google-continue-tag {
  font-size: 12px;
  font-weight: 700;
  color: #1a73e8;
  padding: 4px 10px;
  background: #eff6ff;
  border-radius: 6px;
  flex: none;
  transition: all 0.2s;
}

.google-account-btn:hover .google-continue-tag {
  background: #1a73e8;
  color: white;
}

/* Custom Google Input */
.custom-google-box {
  background: #f8fafc;
  border: 1px dashed var(--border-light);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 20px;
}

.custom-google-label {
  display: block;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-700);
  margin-bottom: 8px;
}

.custom-google-input-row {
  display: flex;
  gap: 10px;
}

.custom-google-input-row input {
  flex: 1;
  background: white;
}

.google-security-notice {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 12px;
  color: var(--ink-500);
  line-height: 1.5;
  background: #fafafa;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

/* Alternative Auth Options */
.auth-gate-alt-options {
  padding: 20px 32px;
  background: #fcfdfe;
}

.alt-options-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-400);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 12px;
}

.alt-options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

@media (max-width: 640px) {
  .alt-options-grid {
    grid-template-columns: 1fr;
  }
}

.alt-auth-card-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: white;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  cursor: pointer;
  text-align: left;
  transition: all 0.2s;
}

.alt-auth-card-btn:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
  transform: translateY(-1px);
}

.alt-auth-card-btn .alt-icon {
  font-size: 20px;
  flex: none;
}

.alt-auth-card-btn b {
  display: block;
  font-size: 13px;
  color: var(--ink-800);
}

.alt-auth-card-btn span {
  display: block;
  font-size: 11.5px;
  color: var(--ink-500);
}

/* Sidebar locked state */
.nav-locked {
  opacity: 0.65;
}

.user-pill-avatar.google-auth-prompt {
  background: white;
  border: 1px solid #e2e8f0;
  display: grid;
  place-items: center;
}