/* ============================================================
   main.css — KDLearnSpace Core Design System
   Font: Inter (supports full Vietnamese Unicode perfectly)
   ============================================================ */

/* ── CSS Variables — Light Theme ── */
:root,
[data-theme="light"] {
  --color-bg:           #f0f4ff;
  --color-surface:      #ffffff;
  --color-surface-2:    #f5f7ff;
  --color-surface-3:    #eaedff;
  --color-border:       #d4daf7;
  --color-border-hover: #97a8f0;

  --color-primary:      #4361ee;
  --color-primary-dark: #2f4dd4;
  --color-primary-light:#eef1ff;
  --color-primary-glow: rgba(67, 97, 238, 0.18);

  --color-secondary:    #7209b7;
  --color-accent:       #f72585;
  --color-success:      #06d6a0;
  --color-warning:      #fbbf24;
  --color-error:        #ef233c;
  --color-info:         #4cc9f0;

  --color-text:         #1a1e3a;
  --color-text-2:       #4a5280;
  --color-text-3:       #8b93bb;
  --color-text-inv:     #ffffff;

  --shadow-sm:  0 1px 4px rgba(67,97,238,0.07), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:  0 4px 18px rgba(67,97,238,0.11), 0 2px 6px rgba(0,0,0,0.05);
  --shadow-lg:  0 8px 32px rgba(67,97,238,0.15), 0 4px 12px rgba(0,0,0,0.07);
  --shadow-xl:  0 20px 60px rgba(67,97,238,0.2);

  --radius-sm:   8px;
  --radius-md:   14px;
  --radius-lg:   20px;
  --radius-xl:   28px;
  --radius-full: 9999px;

  /* Inter for all text — full Vietnamese support */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --nav-h: 64px;
  --transition: 0.22s cubic-bezier(0.4, 0, 0.2, 1);

  --grad-primary: linear-gradient(135deg, #4361ee 0%, #7209b7 100%);
  --grad-hero:    linear-gradient(155deg, #3a56e8 0%, #5c2dae 50%, #7209b7 100%);
  --grad-success: linear-gradient(135deg, #06d6a0, #0096c7);
  --grad-warm:    linear-gradient(135deg, #f72585, #7209b7);
}

/* ── Dark Theme ── */
[data-theme="dark"] {
  --color-bg:           #0d0f1e;
  --color-surface:      #161929;
  --color-surface-2:    #1c1f35;
  --color-surface-3:    #232740;
  --color-border:       #2c3054;
  --color-border-hover: #4361ee;

  --color-primary:      #6480ff;
  --color-primary-dark: #4361ee;
  --color-primary-light:#1a2050;
  --color-primary-glow: rgba(100, 128, 255, 0.22);

  --color-text:         #e6eaff;
  --color-text-2:       #9ba5cc;
  --color-text-3:       #565e88;
  --color-text-inv:     #0d0f1e;

  --shadow-sm: 0 1px 4px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 18px rgba(0,0,0,0.5);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.7);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

code, pre { font-family: var(--font-mono); }

#app { min-height: 100vh; display: flex; flex-direction: column; }

/* ── Navbar ── */
.navbar {
  position: sticky; top: 0; z-index: 100;
  height: var(--nav-h);
  display: flex; align-items: center; gap: 1rem;
  padding: 0 1.5rem;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), border-color var(--transition);
}

.nav-brand {
  display: flex; align-items: center; gap: 0.5rem;
  font-weight: 700; font-size: 1.2rem;
  color: var(--color-primary);
  text-decoration: none;
  white-space: nowrap;
  user-select: none;
}
.brand-icon { font-size: 1.5rem; }

.nav-links {
  display: flex; align-items: center; gap: 0.25rem;
  margin-left: 1rem; flex: 1;
}

.nav-link {
  display: inline-flex; align-items: center;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  font-size: 0.875rem; font-weight: 500;
  color: var(--color-text-2);
  transition: all var(--transition);
  white-space: nowrap;
}
.nav-link:hover { background: var(--color-surface-2); color: var(--color-primary); }
.nav-link.active {
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 600;
}

.nav-actions {
  display: flex; align-items: center; gap: 0.5rem;
  margin-left: auto;
}

.nav-user { display: flex; align-items: center; gap: 0.5rem; }
.welcome-text {
  font-size: 0.875rem; font-weight: 500;
  color: var(--color-text-2);
  white-space: nowrap;
  max-width: 160px; overflow: hidden; text-overflow: ellipsis;
}

/* Avatar button */
.nav-avatar-btn {
  display: flex; align-items: center; justify-content: center;
  text-decoration: none;
}
.nav-avatar {
  width: 34px; height: 34px;
  border-radius: var(--radius-full);
  background: var(--grad-primary);
  color: #fff; font-weight: 700; font-size: 0.875rem;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 2px 8px var(--color-primary-glow);
}
.nav-avatar:hover { transform: scale(1.08); box-shadow: 0 4px 16px var(--color-primary-glow); }

.btn-icon {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: transparent; cursor: pointer;
  color: var(--color-text-2); font-size: 0.75rem; font-weight: 600;
  transition: all var(--transition);
}
.btn-icon:hover {
  background: var(--color-surface-2);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  position: fixed; top: 14px; right: 1rem; z-index: 200;
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); padding: 0.4rem 0.75rem;
  font-size: 1.2rem; cursor: pointer; box-shadow: var(--shadow-sm);
}

/* ── Page Container ── */
.page-container {
  flex: 1;
  padding: calc(var(--nav-h) * 0 + 1.5rem) 1.5rem 2rem;
  max-width: 1200px; margin: 0 auto; width: 100%;
}

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  padding: 0.6rem 1.4rem;
  border-radius: var(--radius-full);
  font-family: var(--font-body); font-size: 0.9rem; font-weight: 600;
  cursor: pointer; border: none; text-decoration: none;
  transition: all var(--transition); white-space: nowrap;
  line-height: 1.4;
}
.btn--primary {
  background: var(--grad-primary); color: var(--color-text-inv);
  box-shadow: 0 3px 12px var(--color-primary-glow);
}
.btn--primary:hover { transform: translateY(-1px); box-shadow: 0 6px 20px var(--color-primary-glow); }
.btn--primary:active { transform: translateY(0); }
.btn--outline {
  background: transparent; color: var(--color-primary);
  border: 2px solid var(--color-primary);
}
.btn--outline:hover { background: var(--color-primary-light); }
.btn--ghost {
  background: transparent; color: var(--color-text-2);
  border: 1px solid var(--color-border);
}
.btn--ghost:hover { background: var(--color-surface-2); color: var(--color-text); }
.btn--danger {
  background: var(--color-error); color: #fff;
  box-shadow: 0 2px 8px rgba(239,35,60,0.25);
}
.btn--danger:hover { opacity: 0.88; }
.btn--lg  { padding: 0.8rem 2rem; font-size: 1rem; }
.btn--sm  { padding: 0.4rem 1rem; font-size: 0.8rem; }
.btn--xs  { padding: 0.25rem 0.65rem; font-size: 0.75rem; }
.btn--full { width: 100%; }
.btn:disabled { opacity: 0.55; cursor: not-allowed; transform: none !important; }

.btn--submit { width: 100%; margin-top: 0.5rem; }

/* ── Forms ── */
.form-group { margin-bottom: 1.1rem; }
.form-label {
  display: flex; align-items: center; gap: 0.35rem;
  font-size: 0.82rem; font-weight: 600;
  color: var(--color-text-2); margin-bottom: 0.4rem;
  letter-spacing: 0.02em;
}
.form-label-readonly {
  font-size: 0.72rem; font-weight: 400;
  color: var(--color-text-3); font-style: italic;
}
.label-required { color: var(--color-error); font-size: 0.9em; }

.form-input {
  width: 100%; padding: 0.65rem 1rem;
  background: var(--color-surface); color: var(--color-text);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md); font-family: var(--font-body); font-size: 0.925rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none; line-height: 1.5;
}
.form-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}
.form-input::placeholder { color: var(--color-text-3); }
.form-input--readonly {
  background: var(--color-surface-2);
  color: var(--color-text-3);
  cursor: not-allowed; border-style: dashed;
}
.form-textarea { resize: vertical; min-height: 90px; }
.form-textarea--tall { min-height: 160px; }
.form-select { appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'%3E%3Cpath fill='%238b93bb' d='M0 0l5 6 5-6z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.8rem center; background-size: 10px; padding-right: 2.5rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0.8rem; }
.form-hint {
  margin-top: 0.35rem; font-size: 0.78rem;
  color: var(--color-text-3); line-height: 1.4;
}

.input-password-wrap { position: relative; }
.input-password-wrap .form-input { padding-right: 2.8rem; }
.btn-eye {
  position: absolute; right: 0.75rem; top: 50%; transform: translateY(-50%);
  background: none; border: none; cursor: pointer;
  font-size: 1rem; color: var(--color-text-3); padding: 0.2rem;
  transition: color var(--transition);
}
.btn-eye:hover { color: var(--color-primary); }

/* ── Auth pages ── */
.auth-page {
  min-height: calc(100vh - var(--nav-h));
  display: flex; align-items: center; justify-content: center;
  padding: 2rem 1rem; position: relative; overflow: hidden;
}
.auth-bg {
  position: absolute; inset: 0; overflow: hidden; z-index: 0;
  background: var(--grad-hero);
}
.auth-blob {
  position: absolute; border-radius: 50%;
  filter: blur(60px); opacity: 0.35;
  animation: blobMove 12s ease-in-out infinite;
}
.blob-1 { width: 400px; height: 400px; background: #4361ee; top: -80px; left: -80px; }
.blob-2 { width: 300px; height: 300px; background: #f72585; bottom: -60px; right: 5%; animation-delay: -4s; }
.blob-3 { width: 250px; height: 250px; background: #7209b7; top: 40%; left: 40%; animation-delay: -8s; }

.auth-card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 2.5rem 2rem;
  width: 100%; max-width: 420px;
  box-shadow: var(--shadow-xl);
  position: relative; z-index: 1;
}
.auth-card--register { max-width: 480px; }

.auth-brand {
  display: flex; align-items: center; gap: 0.6rem;
  margin-bottom: 1.5rem; justify-content: center;
}
.auth-logo { font-size: 2rem; }
.auth-logo-text {
  font-size: 1.4rem; font-weight: 800;
  background: var(--grad-primary);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}

.auth-title { font-size: 1.5rem; font-weight: 700; text-align: center; margin-bottom: 0.3rem; }
.auth-sub { font-size: 0.875rem; color: var(--color-text-2); text-align: center; margin-bottom: 1.5rem; }
.auth-form { display: flex; flex-direction: column; gap: 0; }
.auth-switch { text-align: center; font-size: 0.875rem; color: var(--color-text-2); margin-top: 1.2rem; }

/* ── Dashboard ── */
.dashboard-hero {
  background: var(--grad-hero);
  border-radius: var(--radius-xl);
  padding: 2.5rem 2rem;
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 1.5rem;
  overflow: hidden; position: relative;
}
.hero-title { font-size: 1.75rem; font-weight: 800; color: #fff; margin-bottom: 0.4rem; }
.hero-sub   { font-size: 0.95rem; color: rgba(255,255,255,0.8); }
.hero-illustration { font-size: 5rem; opacity: 0.7; }

.stats-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem;
  margin-bottom: 2rem;
}
.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.stat-icon { font-size: 1.75rem; margin-bottom: 0.4rem; }
.stat-value { font-size: 2rem; font-weight: 800; color: var(--color-primary); line-height: 1; }
.stat-label { font-size: 0.78rem; color: var(--color-text-3); margin-top: 0.2rem; font-weight: 500; }

/* ── Courses Grid ── */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.course-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden; cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  box-shadow: var(--shadow-sm);
}
.course-card:hover {
  transform: translateY(-4px); box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}
.course-card-thumb {
  height: 150px; background: var(--grad-hero) center/cover no-repeat;
  position: relative; display: flex; align-items: center; justify-content: center;
}
.card-emoji { font-size: 3rem; }
.card-level-badge {
  position: absolute; top: 0.6rem; right: 0.6rem;
  background: rgba(0,0,0,0.45); color: #fff;
  padding: 0.2rem 0.5rem; border-radius: var(--radius-full); font-size: 0.75rem;
  backdrop-filter: blur(4px);
}
.course-card-body { padding: 1rem; }
.card-tag {
  display: inline-block; font-size: 0.72rem; font-weight: 600;
  background: var(--color-primary-light); color: var(--color-primary);
  padding: 0.15rem 0.6rem; border-radius: var(--radius-full); margin-bottom: 0.5rem;
}
.course-card-title { font-size: 1rem; font-weight: 700; margin-bottom: 0.35rem; line-height: 1.35; }
.course-card-desc { font-size: 0.8rem; color: var(--color-text-2); line-height: 1.5; margin-bottom: 0.75rem; }
.course-card-footer { display: flex; align-items: center; justify-content: space-between; gap: 0.5rem; }
.course-card-meta { font-size: 0.78rem; color: var(--color-text-3); }
.mini-progress-wrap { display: flex; align-items: center; gap: 0.4rem; flex: 1; justify-content: flex-end; }
.mini-progress { flex: 1; max-width: 80px; height: 6px; background: var(--color-surface-3); border-radius: var(--radius-full); overflow: hidden; }
.mini-progress > div { height: 100%; background: var(--grad-success); border-radius: inherit; transition: width 0.6s ease; }
.mini-pct { font-size: 0.72rem; color: var(--color-text-3); white-space: nowrap; }

/* ── Course Detail ── */
.course-hero {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-xl); overflow: hidden; margin-bottom: 1.5rem;
  box-shadow: var(--shadow-md);
  display: grid; grid-template-columns: 280px 1fr; gap: 0;
}
.course-hero-thumb {
  min-height: 200px; background: var(--grad-hero) center/cover no-repeat;
  display: flex; align-items: center; justify-content: center;
}
.course-hero-emoji { font-size: 4rem; }
.course-hero-info { padding: 1.75rem; display: flex; flex-direction: column; gap: 0.75rem; }
.course-meta-row { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.badge {
  display: inline-flex; align-items: center; gap: 0.25rem;
  padding: 0.2rem 0.7rem; border-radius: var(--radius-full); font-size: 0.75rem; font-weight: 600;
}
.badge--level  { background: var(--color-surface-2); color: var(--color-text-2); border: 1px solid var(--color-border); }
.badge--cat    { background: var(--color-primary-light); color: var(--color-primary); }
.badge--admin  { background: linear-gradient(135deg,#f72585,#7209b7); color: #fff; }
.badge--student { background: var(--color-primary-light); color: var(--color-primary); }

.course-detail-title { font-size: 1.5rem; font-weight: 800; line-height: 1.3; }
.course-detail-desc { font-size: 0.9rem; color: var(--color-text-2); line-height: 1.6; }
.course-detail-stats { display: flex; gap: 1rem; font-size: 0.85rem; color: var(--color-text-2); }
.progress-wrap { display: flex; flex-direction: column; gap: 0.3rem; }
.progress-label { font-size: 0.8rem; color: var(--color-text-2); font-weight: 500; }
.progress-bar-bg { height: 8px; background: var(--color-surface-3); border-radius: var(--radius-full); overflow: hidden; }
.progress-bar-fill { height: 100%; background: var(--grad-success); border-radius: inherit; transition: width 0.7s ease; }
.fill--complete { background: linear-gradient(90deg, #06d6a0, #4cc9f0); }

.course-content-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.lessons-section, .quizzes-section {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 1.25rem; box-shadow: var(--shadow-sm);
}

.lesson-list, .quiz-list { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.lesson-item {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem; border-radius: var(--radius-md);
  cursor: pointer; border: 1px solid transparent;
  transition: all var(--transition);
}
.lesson-item:hover { background: var(--color-surface-2); border-color: var(--color-border); }
.lesson-item.lesson--done { opacity: 0.7; }
.lesson-item.lesson--locked { cursor: not-allowed; opacity: 0.5; }
.lesson-num {
  width: 26px; height: 26px; border-radius: var(--radius-full);
  background: var(--color-primary-light); color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 700; flex-shrink: 0;
}
.lesson-info { flex: 1; min-width: 0; }
.lesson-title { display: block; font-size: 0.875rem; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.lesson-meta { display: block; font-size: 0.75rem; color: var(--color-text-3); }
.lesson-status { font-size: 0.8rem; color: var(--color-text-3); flex-shrink: 0; }

.quiz-item {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem; border-radius: var(--radius-md);
  cursor: pointer; border: 1px solid var(--color-border);
  transition: all var(--transition);
}
.quiz-item:hover { border-color: var(--color-primary); background: var(--color-surface-2); }
.quiz-item.quiz--locked { cursor: not-allowed; opacity: 0.5; }
.quiz-icon { font-size: 1.3rem; }
.quiz-info { flex: 1; }
.quiz-title { display: block; font-size: 0.875rem; font-weight: 600; }
.quiz-meta { display: block; font-size: 0.75rem; color: var(--color-text-3); }
.quiz-score { font-size: 0.85rem; font-weight: 700; padding: 0.2rem 0.6rem; border-radius: var(--radius-full); }
.score--pass { background: rgba(6,214,160,0.15); color: #06d6a0; }
.score--fail { background: rgba(239,35,60,0.1); color: var(--color-error); }
.quiz-btn { font-size: 0.8rem; color: var(--color-primary); font-weight: 600; }

/* ── Lesson page ── */
.lesson-page { max-width: 860px; margin: 0 auto; }
.lesson-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1.25rem; flex-wrap: wrap; }
.lesson-breadcrumb { font-size: 0.85rem; color: var(--color-text-3); }
.breadcrumb-course { color: var(--color-primary); font-weight: 600; }
.lesson-body {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-xl); padding: 2rem; box-shadow: var(--shadow-md);
}
.lesson-title { font-size: 1.75rem; font-weight: 800; margin-bottom: 0.5rem; }
.lesson-meta-row { display: flex; gap: 1rem; font-size: 0.85rem; color: var(--color-text-2); margin-bottom: 1.5rem; }
.video-container { margin-bottom: 1.5rem; border-radius: var(--radius-lg); overflow: hidden; aspect-ratio: 16/9; background: #000; }
.video-container iframe, .video-container video { width: 100%; height: 100%; border: none; }
.lesson-content-body { font-size: 0.95rem; line-height: 1.75; color: var(--color-text-2); }
.lesson-content-body h1, .lesson-content-body h2, .lesson-content-body h3 { color: var(--color-text); margin: 1.25rem 0 0.5rem; font-weight: 700; }
.lesson-content-body code { font-family: var(--font-mono); background: var(--color-surface-3); padding: 0.15rem 0.4rem; border-radius: 4px; font-size: 0.875em; }
.lesson-content-body ul { padding-left: 1.5rem; }
.lesson-content-body p { margin-bottom: 0.75rem; }
.doc-section { margin-top: 1.5rem; padding: 1rem; background: var(--color-surface-2); border-radius: var(--radius-md); }
.lesson-actions { display: flex; justify-content: flex-end; margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--color-border); }

/* ── Progress page ── */
.progress-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.25rem; }
.progress-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 1.25rem; box-shadow: var(--shadow-sm);
  display: flex; flex-direction: column; gap: 0.9rem;
}
.progress-card-header { display: flex; gap: 0.75rem; align-items: center; }
.pcourse-thumb {
  width: 52px; height: 52px; border-radius: var(--radius-md);
  background: var(--grad-hero) center/cover no-repeat;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem; flex-shrink: 0;
}
.pcourse-title { font-size: 0.95rem; font-weight: 700; line-height: 1.3; margin-bottom: 0.2rem; }
.pcourse-meta { font-size: 0.78rem; color: var(--color-text-3); }
.progress-bar-section { display: flex; flex-direction: column; gap: 0.3rem; }
.progress-bar-label { display: flex; justify-content: space-between; font-size: 0.8rem; color: var(--color-text-2); }
.pct-text { font-weight: 700; color: var(--color-primary); }
.quiz-summary { display: flex; justify-content: space-between; align-items: center; font-size: 0.85rem; }
.quiz-summary-label { color: var(--color-text-2); }
.quiz-summary-score { font-weight: 700; padding: 0.15rem 0.5rem; border-radius: var(--radius-full); }
.score--good { background: rgba(6,214,160,0.15); color: #06d6a0; }
.score--low  { background: rgba(239,35,60,0.1); color: var(--color-error); }

/* ── Profile page ── */
.profile-page { max-width: 680px; margin: 0 auto; }
.profile-hero {
  background: var(--grad-hero); border-radius: var(--radius-xl);
  padding: 2rem; display: flex; align-items: center; gap: 1.5rem;
  margin-bottom: 1.5rem; box-shadow: var(--shadow-lg);
}
.profile-avatar-lg {
  width: 72px; height: 72px; border-radius: var(--radius-full);
  background: rgba(255,255,255,0.2); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 2rem; font-weight: 800; border: 3px solid rgba(255,255,255,0.5);
  flex-shrink: 0;
}
.profile-name { font-size: 1.4rem; font-weight: 800; color: #fff; margin-bottom: 0.2rem; }
.profile-username { font-size: 0.9rem; color: rgba(255,255,255,0.75); margin-bottom: 0.5rem; }

.profile-tabs { display: flex; gap: 0.5rem; margin-bottom: 1.25rem; }
.profile-tab {
  flex: 1; padding: 0.65rem 1rem;
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); font-family: var(--font-body); font-size: 0.875rem; font-weight: 600;
  cursor: pointer; color: var(--color-text-2); transition: all var(--transition);
}
.profile-tab.active {
  background: var(--color-primary-light); color: var(--color-primary);
  border-color: var(--color-primary);
}
.profile-panel { display: none; }
.profile-panel.active { display: block; }
.profile-form-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-xl); padding: 1.75rem; box-shadow: var(--shadow-md);
}
.profile-actions { display: flex; justify-content: flex-end; margin-top: 1rem; }

.security-section { display: flex; flex-direction: column; gap: 0.75rem; }
.security-title { font-size: 1rem; font-weight: 700; }
.security-desc { font-size: 0.875rem; color: var(--color-text-2); }
.security-email-preview {
  display: flex; align-items: center; gap: 0.5rem;
  padding: 0.6rem 1rem; background: var(--color-surface-2);
  border-radius: var(--radius-md); font-size: 0.875rem;
  border: 1px solid var(--color-border);
}
.security-email-label { font-weight: 600; color: var(--color-text-3); }
.security-email-val { color: var(--color-text); font-weight: 500; }

/* ── Quiz page ── */
.quiz-page { max-width: 760px; margin: 0 auto; }
.quiz-topbar {
  display: flex; align-items: center; gap: 1rem; justify-content: space-between;
  margin-bottom: 1rem; flex-wrap: wrap;
}
.quiz-title-wrap { flex: 1; }
.quiz-page-title { font-size: 1.2rem; font-weight: 800; }
.quiz-course-name { font-size: 0.8rem; color: var(--color-text-3); }
.quiz-timer-wrap { display: flex; align-items: center; gap: 0.4rem; }
.quiz-timer { font-size: 1.2rem; font-weight: 700; color: var(--color-primary); font-family: var(--font-mono); }
.quiz-timer.timer--warning { color: var(--color-error); animation: timerPulse 1s ease infinite; }
.quiz-progress-bar-wrap { height: 5px; background: var(--color-surface-3); border-radius: var(--radius-full); margin-bottom: 0.4rem; overflow: hidden; }
.quiz-progress-bar { height: 100%; background: var(--grad-primary); border-radius: inherit; transition: width 0.3s ease; }
.quiz-answered-text { font-size: 0.8rem; color: var(--color-text-3); margin-bottom: 1.25rem; }
.quiz-questions { display: flex; flex-direction: column; gap: 1.25rem; }
.quiz-question-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 1.25rem; box-shadow: var(--shadow-sm);
}
.question-number { font-size: 0.75rem; font-weight: 700; color: var(--color-primary); margin-bottom: 0.4rem; text-transform: uppercase; letter-spacing: 0.08em; }
.question-text { font-size: 1rem; font-weight: 600; margin-bottom: 1rem; line-height: 1.5; }
.question-options { display: flex; flex-direction: column; gap: 0.5rem; }
.quiz-option {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem 1rem; border-radius: var(--radius-md);
  border: 1.5px solid var(--color-border); cursor: pointer;
  transition: all var(--transition); background: var(--color-surface-2);
}
.quiz-option:hover { border-color: var(--color-primary); background: var(--color-primary-light); }
.quiz-option.selected { border-color: var(--color-primary); background: var(--color-primary-light); box-shadow: 0 0 0 2px var(--color-primary-glow); }
.option-letter {
  width: 26px; height: 26px; border-radius: var(--radius-full); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 700;
  background: var(--color-surface-3); color: var(--color-text-2);
  transition: background var(--transition), color var(--transition);
}
.quiz-option.selected .option-letter { background: var(--color-primary); color: #fff; }
.option-text { font-size: 0.9rem; }
.quiz-submit-wrap { margin-top: 2rem; display: flex; justify-content: center; }

/* ── Quiz Result ── */
.quiz-result-page { max-width: 680px; margin: 0 auto; }
.result-card {
  background: var(--color-surface); border: 2px solid var(--color-border);
  border-radius: var(--radius-xl); padding: 2rem; text-align: center;
  box-shadow: var(--shadow-lg); margin-bottom: 1.5rem;
}
.result-card.result--pass { border-color: var(--color-success); }
.result-card.result--fail { border-color: var(--color-error); }
.result-score-ring { position: relative; width: 130px; height: 130px; margin: 0 auto 1.25rem; }
.result-score-ring svg { width: 130px; height: 130px; }
.ring-fill { transition: stroke-dashoffset 1s ease; }
.ring-text { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.ring-pct { font-size: 1.75rem; font-weight: 800; color: var(--color-text); }
.ring-label { font-size: 0.75rem; color: var(--color-text-3); }
.result-title { font-size: 1.2rem; font-weight: 700; margin-bottom: 0.75rem; }
.result-stats { display: flex; gap: 1.5rem; justify-content: center; font-size: 0.9rem; font-weight: 600; margin-bottom: 1.25rem; }
.stat-correct { color: var(--color-success); }
.stat-wrong   { color: var(--color-error); }
.result-actions { display: flex; gap: 0.75rem; justify-content: center; }
.result-review { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 1.25rem; box-shadow: var(--shadow-sm); }
.review-title { font-size: 1rem; font-weight: 700; margin-bottom: 1rem; }
.review-item { padding: 0.75rem; border-radius: var(--radius-md); margin-bottom: 0.5rem; border: 1px solid var(--color-border); }
.review-item.review--correct { border-color: var(--color-success); background: rgba(6,214,160,0.05); }
.review-item.review--wrong   { border-color: var(--color-error); background: rgba(239,35,60,0.04); }
.review-q { display: flex; align-items: flex-start; gap: 0.5rem; }
.review-num { font-weight: 700; color: var(--color-text-3); font-size: 0.8rem; min-width: 1.5rem; }
.review-text { flex: 1; font-size: 0.875rem; font-weight: 500; }
.review-icon { font-size: 0.9rem; }
.review-answers { display: flex; flex-direction: column; gap: 0.25rem; padding-left: 2rem; margin-top: 0.4rem; font-size: 0.8rem; }
.your-ans    { color: var(--color-error); }
.correct-ans { color: var(--color-success); }

/* ── Admin page ── */
.admin-page { }
.admin-tabs { display: flex; gap: 0.5rem; margin-bottom: 1.25rem; }
.admin-tab {
  padding: 0.55rem 1.25rem;
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-full); font-family: var(--font-body); font-size: 0.875rem; font-weight: 600;
  cursor: pointer; color: var(--color-text-2); transition: all var(--transition);
}
.admin-tab.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.admin-panel { display: none; }
.admin-panel.active { display: block; }
.admin-panel-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.admin-table-wrap { overflow-x: auto; border-radius: var(--radius-lg); border: 1px solid var(--color-border); }
.admin-table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
.admin-table th {
  padding: 0.75rem 1rem; text-align: left;
  background: var(--color-surface-2); color: var(--color-text-2);
  font-weight: 600; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.05em;
  border-bottom: 1px solid var(--color-border);
}
.admin-table td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--color-border); color: var(--color-text); }
.admin-table tr:last-child td { border-bottom: none; }
.admin-table tr:hover td { background: var(--color-surface-2); }
.action-cell { display: flex; gap: 0.4rem; flex-wrap: wrap; }

/* ── Modals ── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(0,0,0,0.55); backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center; padding: 1rem;
}
.modal {
  background: var(--color-surface);
  border-radius: var(--radius-xl); padding: 2rem;
  width: 100%; max-width: 500px; max-height: 90vh; overflow-y: auto;
  box-shadow: var(--shadow-xl);
}
.modal--wide { max-width: 720px; }
.modal-title { font-size: 1.2rem; font-weight: 700; margin-bottom: 1.25rem; }
.modal-toolbar { margin-bottom: 1rem; }
.modal-actions { display: flex; justify-content: flex-end; gap: 0.6rem; margin-top: 1.25rem; }
.modal-list { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.modal-list-item {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem; background: var(--color-surface-2);
  border: 1px solid var(--color-border); border-radius: var(--radius-md);
}
.item-order { font-weight: 700; color: var(--color-text-3); min-width: 24px; text-align: center; }
.item-title { flex: 1; font-size: 0.875rem; font-weight: 600; }
.item-type { font-size: 0.75rem; color: var(--color-text-3); }
.item-meta { font-size: 0.78rem; color: var(--color-text-3); }
.item-actions { display: flex; gap: 0.4rem; }

/* Question builder in admin */
.question-form-card {
  background: var(--color-surface-2); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 1rem; margin-bottom: 0.75rem;
}
.question-form-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 0.6rem; font-weight: 700; color: var(--color-primary); font-size: 0.875rem; }
.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.5rem; margin: 0.5rem 0; }
.option-row { display: flex; align-items: center; gap: 0.4rem; }
.option-row input[type="radio"] { flex-shrink: 0; accent-color: var(--color-primary); width: 15px; height: 15px; }
.btn-remove-q { background: none; border: none; cursor: pointer; color: var(--color-error); font-size: 1rem; }
.hint-text { font-size: 0.75rem; color: var(--color-text-3); margin-top: 0.3rem; }

/* ── Chatbot ── */
.chatbot-fab {
  position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 500;
  width: 52px; height: 52px; border-radius: var(--radius-full);
  background: var(--grad-primary); color: #fff; border: none; cursor: pointer;
  box-shadow: 0 4px 20px var(--color-primary-glow);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  transition: transform var(--transition), box-shadow var(--transition);
}
.chatbot-fab:hover { transform: scale(1.1); box-shadow: 0 8px 28px var(--color-primary-glow); }
.fab-badge {
  position: absolute; top: -4px; right: -4px;
  width: 18px; height: 18px; border-radius: var(--radius-full);
  background: var(--color-error); color: #fff;
  font-size: 0.65rem; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

.chatbot-widget {
  position: fixed; bottom: 5rem; right: 1.5rem; z-index: 499;
  width: 340px; background: var(--color-surface);
  border: 1px solid var(--color-border); border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  display: flex; flex-direction: column;
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s ease, opacity 0.25s ease;
  opacity: 0;
}
.chatbot-widget.open { max-height: 480px; opacity: 1; }
.chatbot-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.85rem 1rem; border-bottom: 1px solid var(--color-border);
  background: var(--grad-primary); border-radius: var(--radius-xl) var(--radius-xl) 0 0;
}
.chatbot-title { display: flex; align-items: center; gap: 0.6rem; }
.chatbot-avatar { font-size: 1.3rem; }
.chatbot-name { display: block; color: #fff; font-weight: 700; font-size: 0.875rem; }
.chatbot-status { display: block; color: rgba(255,255,255,0.75); font-size: 0.72rem; }
.chatbot-close { background: none; border: none; color: rgba(255,255,255,0.85); font-size: 1rem; cursor: pointer; padding: 0.2rem; border-radius: 4px; transition: background var(--transition); }
.chatbot-close:hover { background: rgba(255,255,255,0.15); }
.chatbot-messages { flex: 1; overflow-y: auto; padding: 0.75rem; display: flex; flex-direction: column; gap: 0.6rem; scroll-behavior: smooth; }
.chat-message { display: flex; align-items: flex-end; gap: 0.4rem; }
.chat-message--bot { justify-content: flex-start; }
.chat-message--user { justify-content: flex-end; }
.chat-avatar { font-size: 1.1rem; flex-shrink: 0; }
.chat-bubble {
  max-width: 80%; padding: 0.55rem 0.85rem;
  border-radius: 14px; font-size: 0.825rem; line-height: 1.55;
}
.chat-message--bot .chat-bubble { background: var(--color-surface-2); color: var(--color-text); border-radius: 4px 14px 14px 14px; }
.chat-message--user .chat-bubble { background: var(--grad-primary); color: #fff; border-radius: 14px 4px 14px 14px; }
.chatbot-input-area { display: flex; gap: 0.4rem; padding: 0.75rem; border-top: 1px solid var(--color-border); }
.chatbot-input { flex: 1; padding: 0.5rem 0.75rem; border: 1px solid var(--color-border); border-radius: var(--radius-full); font-family: var(--font-body); font-size: 0.825rem; background: var(--color-surface-2); color: var(--color-text); outline: none; }
.chatbot-input:focus { border-color: var(--color-primary); }
.chatbot-send { width: 32px; height: 32px; border-radius: var(--radius-full); background: var(--grad-primary); color: #fff; border: none; cursor: pointer; font-size: 0.9rem; display: flex; align-items: center; justify-content: center; transition: transform var(--transition); }
.chatbot-send:hover { transform: scale(1.1); }
.typing-indicator { display: flex; gap: 4px; align-items: center; padding: 0.55rem 0.9rem; }
.typing-indicator span { width: 6px; height: 6px; border-radius: 50%; background: var(--color-text-3); animation: typingDot 1.2s ease infinite; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

/* ── Loading overlay ── */
.loading-overlay {
  position: fixed; inset: 0; z-index: 9999;
  display: flex; align-items: center; justify-content: center;
  background: var(--color-bg);
  transition: opacity 0.5s ease;
}
.loading-overlay.fade-out { opacity: 0; pointer-events: none; }
.loading-spinner { text-align: center; }
.spinner-ring {
  width: 48px; height: 48px; margin: 0 auto 0.75rem;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
.spinner-text { font-size: 1rem; font-weight: 700; color: var(--color-primary); }
.spinner-sm {
  display: inline-block; width: 16px; height: 16px;
  border: 2px solid rgba(255,255,255,0.4); border-top-color: #fff;
  border-radius: 50%; animation: spin 0.7s linear infinite;
  vertical-align: middle;
}

/* ── Section helpers ── */
.section { margin-bottom: 2rem; }
.section-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.section-title { font-size: 1.1rem; font-weight: 700; }
.page-header { margin-bottom: 1.75rem; }
.page-title { font-size: 1.75rem; font-weight: 800; margin-bottom: 0.3rem; }
.page-sub { font-size: 0.9rem; color: var(--color-text-2); }
.empty-state { text-align: center; padding: 3rem 1rem; color: var(--color-text-3); }
.empty-state span { font-size: 3rem; display: block; margin-bottom: 0.75rem; }
.empty-state p { font-size: 0.9rem; margin-bottom: 1rem; }
.empty-text { font-size: 0.875rem; color: var(--color-text-3); padding: 0.75rem 0; }
.back-btn { margin-bottom: 1rem; }
.link { color: var(--color-primary); font-weight: 600; text-decoration: none; }
.link:hover { text-decoration: underline; }
.page-loading { display: flex; justify-content: center; padding: 4rem; }

/* ── Courses page ── */
.courses-page .page-header { margin-bottom: 1.5rem; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .navbar { padding: 0 1rem; }
  .nav-links { display: none; flex-direction: column; position: fixed; top: var(--nav-h); left: 0; right: 0; background: var(--color-surface); border-bottom: 1px solid var(--color-border); padding: 1rem; z-index: 99; box-shadow: var(--shadow-md); gap: 0.3rem; }
  .nav-links.nav-links--open { display: flex; }
  .nav-hamburger { display: block; }
  .welcome-text { display: none; }
  .stats-grid { grid-template-columns: repeat(3, 1fr); }
  .course-hero { grid-template-columns: 1fr; }
  .course-hero-thumb { min-height: 160px; }
  .course-content-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .dashboard-hero { flex-direction: column; gap: 0.5rem; text-align: center; }
  .hero-illustration { font-size: 3rem; }
  .hero-title { font-size: 1.35rem; }
  .chatbot-widget { width: calc(100vw - 2rem); right: 1rem; }
  .options-grid { grid-template-columns: 1fr; }
  .action-cell { flex-wrap: wrap; }
}

@media (max-width: 480px) {
  .page-container { padding: 1rem 1rem 2rem; }
  .auth-card { padding: 1.75rem 1.25rem; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .stat-card:nth-child(3) { grid-column: span 2; }
  .course-detail-stats { flex-wrap: wrap; gap: 0.5rem; }
}