/* ============================================================
   CarEDU — Main Stylesheet
   Aesthetic: Refined automotive editorial — dark, confident,
   with warm amber accents and strong typographic hierarchy
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,400;0,600;0,700;1,400;1,600&family=DM+Sans:wght@300;400;500;600&family=DM+Mono:wght@400;500&display=swap');

/* ── Variables ─────────────────────────────────────────────── */
:root {
  --bg:        #ffffff;
  --bg-2:      #f8f9fb;
  --bg-3:      #f0f2f5;
  --bg-4:      #e8ebf0;
  --border:    #dde1e9;
  --border-lt: #c8cdd8;

  --text:      #1a1d23;
  --text-2:    #4a5060;
  --text-3:    #8a90a0;

  --amber:     #c87d18;
  --amber-lt:  #e8a030;
  --amber-dim: rgba(200, 125, 24, 0.08);

  --green:     #1e8a6e;
  --purple:    #7048b8;
  --red:       #c0392b;
  --red-dim:   rgba(192, 57, 43, 0.08);
  --green-dim: rgba(30, 138, 110, 0.08);

  --radius:    10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow:    0 2px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);

  --font-display: 'Cormorant Garamond', Georgia, serif;
  --font-ui:      'DM Sans', system-ui, sans-serif;
  --font-mono:    'DM Mono', monospace;

  --max-w:     1100px;
  --max-w-sm:  760px;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-ui);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; font-family: inherit; }

/* ── Typography ─────────────────────────────────────────────── */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); margin-bottom: 1rem; }
h3 { font-size: 1.4rem; margin: 1.8rem 0 0.75rem; color: var(--text); }
h4 { font-size: 1.1rem; margin-bottom: 0.5rem; }

p { color: var(--text-2); margin-bottom: 1rem; }
p.lead { font-size: 1.1rem; color: var(--text); line-height: 1.8; }

strong { color: var(--text); font-weight: 600; }

/* ── Site Header ────────────────────────────────────────────── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  height: 64px;
  display: flex;
  align-items: center;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 10px;
}

.site-logo .logo-car { font-size: 1.2rem; }
.site-logo .logo-text { color: var(--text); }
.site-logo .logo-accent { color: var(--amber); }

.header-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-nav a, .header-nav button {
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-2);
  border: none;
  background: transparent;
  transition: all 0.2s;
}

.header-nav a:hover, .header-nav button:hover {
  background: var(--bg-3);
  color: var(--text);
}

.header-nav .btn-reset {
  color: var(--red);
  font-size: 0.8rem;
  opacity: 0.6;
}
.header-nav .btn-reset:hover { opacity: 1; background: var(--red-dim); }

/* ── Page Wrapper ───────────────────────────────────────────── */
.page-wrap {
  padding-top: 64px;
  min-height: 100vh;
}

/* ── Read Progress Bar ──────────────────────────────────────── */
.read-progress-bar {
  position: fixed;
  top: 64px; left: 0;
  height: 3px;
  background: var(--amber);
  z-index: 99;
  transition: width 0.1s;
  width: 0;
}

/* ── Hero Section (Index) ───────────────────────────────────── */
.hero {
  position: relative;
  overflow: hidden;
  padding: 80px 24px 70px;
  text-align: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, rgba(200,125,24,0.06) 0%, transparent 70%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(112,72,184,0.04) 0%, transparent 60%);
}

.hero-grid-pattern {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(180,185,200,0.25) 1px, transparent 1px),
    linear-gradient(90deg, rgba(180,185,200,0.25) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 20%, transparent 80%);
}

.hero-inner {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--amber-dim);
  border: 1px solid rgba(232,160,48,0.3);
  color: var(--amber);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 28px;
}

.hero h1 {
  font-family: var(--font-display);
  color: var(--text);
  margin-bottom: 20px;
  font-weight: 700;
  font-style: italic;
}

.hero h1 em { font-style: italic; color: var(--amber); }

.hero p {
  font-size: 1.15rem;
  max-width: 560px;
  margin: 0 auto 40px;
  color: var(--text-2);
}

/* Overall Progress Bar */
.overall-progress-wrap {
  max-width: 440px;
  margin: 0 auto 48px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
}

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

.op-label { font-size: 0.85rem; font-weight: 600; color: var(--text-2); letter-spacing: 0.04em; text-transform: uppercase; }
.op-pct { font-family: var(--font-mono); font-size: 0.9rem; color: var(--amber); }

.progress-track {
  height: 8px;
  background: var(--bg-4);
  border-radius: 100px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--amber), var(--amber-lt));
  border-radius: 100px;
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  width: 0;
}

/* Stats Row */
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  margin-top: 20px;
}

.stat-item { text-align: center; }
.stat-num { display: block; font-family: var(--font-display); font-size: 1.6rem; font-weight: 700; color: var(--amber); }
.stat-lbl { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-3); }

/* ── Section Titles ─────────────────────────────────────────── */
.section {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 80px;
}

.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 32px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.section-header h2 {
  font-family: var(--font-display);
  font-size: 1.8rem;
  margin: 0;
}

.section-header span {
  font-size: 0.85rem;
  color: var(--text-3);
}

/* ── Course Cards (Index) ───────────────────────────────────── */
#course-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.course-card {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
  display: block;
  position: relative;
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-lt);
}

.course-card.done { border-color: rgba(76,175,147,0.3); }

.course-card-accent {
  height: 4px;
  width: 100%;
}

.course-card-body { padding: 28px 28px 24px; }

.course-icon {
  font-size: 2.2rem;
  margin-bottom: 16px;
  display: block;
}

.course-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 100px;
  border: 1px solid;
  margin-bottom: 14px;
}

.course-card h3 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  margin: 0 0 6px;
  color: var(--text);
}

.course-card p { font-size: 0.9rem; color: var(--text-2); margin-bottom: 16px; }

.card-meta {
  display: flex;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-3);
  margin-bottom: 20px;
}

.card-progress { display: flex; align-items: center; gap: 12px; }

.card-progress-bar {
  flex: 1;
  height: 5px;
  background: var(--bg-4);
  border-radius: 100px;
  overflow: hidden;
}

.card-progress-fill {
  height: 100%;
  border-radius: 100px;
  transition: width 0.6s ease;
}

.card-progress-label {
  font-size: 0.78rem;
  color: var(--text-3);
  font-family: var(--font-mono);
  white-space: nowrap;
}

/* ── How It Works ───────────────────────────────────────────── */
.how-it-works {
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 60px 24px;
  margin-bottom: 0;
}

.how-grid {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
  padding-top: 32px;
}

.how-item { text-align: center; }

.how-icon {
  width: 56px; height: 56px;
  background: var(--amber-dim);
  border: 1px solid rgba(232,160,48,0.2);
  border-radius: var(--radius-lg);
  font-size: 1.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.how-item h4 { font-size: 1rem; color: var(--text); margin-bottom: 8px; }
.how-item p  { font-size: 0.88rem; color: var(--text-2); }

/* ── Back Button ────────────────────────────────────────────── */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  color: var(--text-2);
  padding: 8px 0;
  margin-bottom: 24px;
  transition: color 0.2s;
}
.back-btn:hover { color: var(--amber); }

/* ── Course Hero (courses.html) ─────────────────────────────── */
.course-hero {
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  padding: 48px 24px 40px;
  position: relative;
  overflow: hidden;
}

.course-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 100% at 100% 50%, rgba(200,125,24,0.05) 0%, transparent 60%);
}

.course-hero-inner {
  position: relative;
  max-width: var(--max-w-sm);
  margin: 0 auto;
}

.course-hero-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 100px;
  border: 1px solid;
  margin-bottom: 16px;
}

.course-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 14px;
}

.hero-desc { font-size: 1rem; color: var(--text-2); margin-bottom: 20px; }

.hero-meta {
  display: flex;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-3);
  margin-bottom: 24px;
}

.hero-progress { display: flex; align-items: center; gap: 14px; }

.hero-progress-bar {
  flex: 1;
  max-width: 260px;
  height: 6px;
  background: var(--bg-4);
  border-radius: 100px;
  overflow: hidden;
}

.hero-progress-fill {
  height: 100%;
  border-radius: 100px;
  transition: width 0.8s ease;
  width: 0;
}

#hero-pct { font-size: 0.85rem; color: var(--text-2); font-family: var(--font-mono); }

/* ── Lesson List ────────────────────────────────────────────── */
.course-content {
  max-width: var(--max-w-sm);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.lesson-list-title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: 16px;
  color: var(--text-2);
  font-style: italic;
}

#lesson-list { display: flex; flex-direction: column; gap: 10px; }

.lesson-item {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px 20px;
  transition: all 0.2s;
}

.lesson-item:hover {
  background: var(--bg-3);
  border-color: var(--border-lt);
  transform: translateX(4px);
}

.lesson-item.done {
  border-color: rgba(76,175,147,0.25);
  background: rgba(76,175,147,0.04);
}

.lesson-item.quiz-item {
  border-style: dashed;
  margin-top: 8px;
}

.lesson-num {
  width: 36px; height: 36px;
  min-width: 36px;
  background: var(--bg-4);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-2);
}

.lesson-item.done .lesson-num {
  background: var(--green-dim);
  color: var(--green);
}

.lesson-info { flex: 1; }
.lesson-title { display: block; font-size: 0.97rem; font-weight: 500; color: var(--text); margin-bottom: 3px; }
.lesson-dur { font-size: 0.8rem; color: var(--text-3); }
.lesson-arrow { color: var(--text-3); font-size: 1.1rem; }

.review-tag {
  font-size: 0.75rem;
  background: var(--green-dim);
  color: var(--green);
  padding: 3px 10px;
  border-radius: 100px;
  font-weight: 500;
}

/* ── Lesson Layout ──────────────────────────────────────────── */
.lesson-page {
  display: grid;
  grid-template-columns: 1fr 280px;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px 24px 100px;
  gap: 40px;
  align-items: start;
}

.lesson-main { min-width: 0; }

/* Lesson nav bar */
#lesson-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 64px;
  z-index: 50;
  gap: 16px;
}

.lesson-nav-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  text-align: center;
}

.lesson-nav-title {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
  max-width: 300px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ── Lesson Content Styles ──────────────────────────────────── */
#lesson-content {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px 44px;
  line-height: 1.8;
}

#lesson-content h2 {
  font-size: 2rem;
  margin-bottom: 20px;
  color: var(--text);
}

#lesson-content h3 {
  font-size: 1.3rem;
  color: var(--text);
  margin: 2rem 0 1rem;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

#lesson-content h4 { color: var(--text); }
#lesson-content p  { color: var(--text-2); }

.info-box {
  display: flex;
  gap: 16px;
  background: var(--amber-dim);
  border: 1px solid rgba(232,160,48,0.25);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  margin: 24px 0;
  align-items: flex-start;
}

.info-icon { font-size: 1.3rem; flex-shrink: 0; line-height: 1; margin-top: 2px; }
.info-box p { color: var(--text); margin: 0; }

.question-card {
  display: flex;
  gap: 16px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  margin: 12px 0;
  align-items: flex-start;
}

.q-number {
  width: 32px; height: 32px;
  min-width: 32px;
  background: var(--amber-dim);
  color: var(--amber);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  font-family: var(--font-mono);
  margin-top: 2px;
}

.q-content h4 { color: var(--text); margin-bottom: 6px; }
.q-content p  { margin: 0; font-size: 0.93rem; }

.tip-box {
  background: var(--bg-3);
  border-left: 3px solid var(--amber);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  padding: 20px 24px;
  margin: 28px 0;
}

.tip-box h4 { color: var(--amber); margin-bottom: 8px; }
.tip-box p  { margin: 0; font-size: 0.93rem; }

.rule-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.rule-card {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  text-align: center;
}

.rule-number {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--amber);
  margin-bottom: 10px;
  line-height: 1;
}

.rule-text { font-size: 0.83rem; color: var(--text-2); }

.cost-table {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 20px 0;
}

.cost-row {
  display: grid;
  grid-template-columns: 1fr auto;
  padding: 13px 20px;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border);
  gap: 16px;
  align-items: center;
}

.cost-row:last-child { border-bottom: none; }
.cost-row.header { background: var(--bg-3); font-size: 0.8rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-3); }
.cost-row.total { background: var(--amber-dim); font-weight: 600; color: var(--amber); }

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 20px 0;
}

.compare-col {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.compare-col h4 { margin-bottom: 14px; font-size: 1rem; }
.compare-col.new  h4 { color: var(--amber); }
.compare-col.used h4 { color: var(--green); }
.compare-col.cpo  h4 { color: var(--purple); }

.compare-col ul { list-style: none; padding: 0; }
.compare-col li { font-size: 0.85rem; color: var(--text-2); padding: 5px 0; border-bottom: 1px solid var(--border); }
.compare-col li:last-child { border: none; }

.styled-list { padding-left: 20px; margin: 12px 0; }
.styled-list li { color: var(--text-2); margin-bottom: 8px; font-size: 0.93rem; }
.styled-list li strong { color: var(--text); }

.car-type-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.car-type-card {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  transition: border-color 0.2s, transform 0.2s;
}

.car-type-card:hover { border-color: var(--border-lt); transform: translateY(-2px); }
.car-type-icon { font-size: 2rem; margin-bottom: 12px; display: block; }
.car-type-card h4 { font-size: 1rem; color: var(--text); margin-bottom: 8px; }
.car-type-card p  { font-size: 0.82rem; color: var(--text-2); margin-bottom: 12px; }

.type-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.type-tags span {
  font-size: 0.7rem;
  background: var(--bg-4);
  color: var(--text-3);
  padding: 3px 8px;
  border-radius: 100px;
  border: 1px solid var(--border);
}

.sticker-section {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  margin: 12px 0;
}

.sticker-label {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 8px;
}

.sticker-section p { font-size: 0.9rem; margin: 0; }

/* ── Lesson Sidebar ─────────────────────────────────────────── */
#lesson-sidebar {
  position: sticky;
  top: 120px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 24px;
}

.sidebar-section { margin-bottom: 24px; }
.sidebar-section:last-child { margin-bottom: 0; }

.sidebar-title {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 12px;
}

.sidebar-progress-wrap { display: flex; align-items: center; gap: 12px; font-size: 0.82rem; color: var(--text-2); font-family: var(--font-mono); }

.sidebar-progress-bar {
  flex: 1;
  height: 5px;
  background: var(--bg-4);
  border-radius: 100px;
  overflow: hidden;
}

.sidebar-progress-fill {
  height: 100%;
  border-radius: 100px;
  width: 0;
  transition: width 0.8s ease;
}

.sidebar-lesson {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: var(--radius);
  margin-bottom: 4px;
  transition: background 0.15s;
  font-size: 0.85rem;
  color: var(--text-2);
}

.sidebar-lesson:hover { background: var(--bg-3); color: var(--text); }
.sidebar-lesson.active { background: var(--amber-dim); color: var(--amber); }
.sidebar-lesson.done { color: var(--green); }

.sl-num { width: 20px; min-width: 20px; text-align: center; font-size: 0.78rem; font-weight: 600; }
.sl-title { flex: 1; line-height: 1.3; }

.btn-mark-complete {
  width: 100%;
  padding: 12px;
  border: 1px solid;
  border-radius: var(--radius-lg);
  background: transparent;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.2s;
  margin-top: 8px;
}

.btn-mark-complete:hover { opacity: 0.8; }
.btn-mark-complete.completed { opacity: 0.5; cursor: default; }

/* ── Lesson Footer ──────────────────────────────────────────── */
#lesson-footer {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(16px);
  border-top: 1px solid var(--border);
  padding: 14px 24px;
  z-index: 50;
  box-shadow: 0 -2px 12px rgba(0,0,0,0.06);
}

.lesson-footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.nav-btn {
  font-size: 0.85rem;
  color: var(--text-2);
  padding: 8px 0;
  transition: color 0.2s;
}
.nav-btn:hover { color: var(--amber); }

.btn-complete {
  padding: 11px 28px;
  border-radius: var(--radius-lg);
  border: none;
  color: #000;
  font-weight: 700;
  font-size: 0.9rem;
  transition: all 0.2s;
  white-space: nowrap;
}

.btn-complete:hover { transform: scale(1.03); }
.btn-complete.completed { opacity: 0.5; cursor: default; transform: none; }

/* ── Quiz Pages ─────────────────────────────────────────────── */
.quiz-page-wrap {
  max-width: 700px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.quiz-intro {
  text-align: center;
  padding: 40px 0;
}

.quiz-intro-icon { font-size: 3.5rem; margin-bottom: 20px; display: block; }

.quiz-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: 100px;
  border: 1px solid;
  margin-bottom: 20px;
}

.quiz-intro h1 { margin-bottom: 16px; }
.quiz-intro p { max-width: 480px; margin: 0 auto 24px; }

.prev-score {
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 14px 20px;
  font-size: 0.9rem;
  color: var(--text-2);
  margin-bottom: 24px;
  display: inline-block;
}

.quiz-rules {
  list-style: none;
  text-align: left;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  margin: 0 auto 32px;
  max-width: 400px;
}

.quiz-rules li { font-size: 0.9rem; color: var(--text-2); padding: 6px 0; border-bottom: 1px solid var(--border); }
.quiz-rules li:last-child { border: none; }

.btn-start {
  padding: 14px 40px;
  border-radius: var(--radius-lg);
  border: none;
  color: #000;
  font-weight: 700;
  font-size: 1rem;
  transition: all 0.2s;
  display: inline-block;
  margin-bottom: 16px;
}

.btn-start:hover { transform: scale(1.03); }

.back-link { display: block; font-size: 0.85rem; color: var(--text-3); margin-top: 12px; }
.back-link:hover { color: var(--text-2); }

.quiz-progress-row {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
  font-size: 0.82rem;
  color: var(--text-3);
}

.quiz-progress-bar {
  flex: 1;
  height: 4px;
  background: var(--bg-4);
  border-radius: 100px;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  border-radius: 100px;
  transition: width 0.5s ease;
}

.quiz-q-card {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 36px;
}

.quiz-q-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.quiz-q-text {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--text);
  margin-bottom: 28px;
  line-height: 1.4;
}

.quiz-options { display: flex; flex-direction: column; gap: 12px; margin-bottom: 20px; }

.quiz-option {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  text-align: left;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  font-size: 0.93rem;
  color: var(--text-2);
  transition: all 0.2s;
  width: 100%;
}

.quiz-option:hover:not(:disabled) {
  background: var(--bg-4);
  border-color: var(--border-lt);
  color: var(--text);
}

.quiz-option.correct  { background: var(--green-dim); border-color: rgba(76,175,147,0.5); color: var(--green); }
.quiz-option.wrong    { background: var(--red-dim); border-color: rgba(224,86,86,0.4); color: var(--red); }
.quiz-option:disabled { cursor: default; }

.opt-letter {
  width: 26px; height: 26px;
  min-width: 26px;
  background: var(--bg-4);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.78rem;
  font-family: var(--font-mono);
}

.feedback-box {
  border-radius: var(--radius-lg);
  padding: 16px 20px;
  margin-top: 4px;
  animation: fadeIn 0.3s ease;
}

.feedback-box.correct { background: var(--green-dim); border: 1px solid rgba(76,175,147,0.3); }
.feedback-box.wrong   { background: var(--red-dim); border: 1px solid rgba(224,86,86,0.3); }
.feedback-box strong  { display: block; margin-bottom: 6px; }
.feedback-box p       { margin: 0; font-size: 0.88rem; }
.feedback-box.correct strong { color: var(--green); }
.feedback-box.wrong   strong { color: var(--red); }

.quiz-next { text-align: right; margin-top: 20px; }

.btn-next-q {
  padding: 12px 28px;
  border-radius: var(--radius-lg);
  border: none;
  color: #000;
  font-weight: 700;
  font-size: 0.9rem;
  transition: all 0.2s;
}

.btn-next-q:hover { transform: scale(1.03); }

/* Quiz Results */
.quiz-results { text-align: center; padding: 40px 0; }
.result-emoji { font-size: 4rem; margin-bottom: 20px; display: block; animation: bounceIn 0.6s ease; }

.result-score-circle {
  width: 120px; height: 120px;
  border-radius: 50%;
  border: 4px solid;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 24px auto;
  flex-direction: row;
}

.score-big { font-family: var(--font-display); font-size: 3rem; font-weight: 700; color: var(--text); line-height: 1; }
.score-denom { font-family: var(--font-display); font-size: 1.4rem; color: var(--text-3); align-self: flex-end; margin-bottom: 10px; }

.result-pct { font-size: 1.3rem; font-weight: 700; margin-bottom: 12px; }

.result-breakdown {
  text-align: left;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 28px 0;
}

.result-q {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 16px;
  font-size: 0.85rem;
  color: var(--text-2);
  border-bottom: 1px solid var(--border);
}

.result-q:last-child { border: none; }
.result-q.correct { color: var(--green); }
.result-q.wrong   { color: var(--red); }

.result-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 12px;
}

.btn-retake {
  padding: 12px 24px;
  border-radius: var(--radius-lg);
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-weight: 500;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-block;
}

.btn-retake:hover { background: var(--bg-4); color: var(--text); }

.btn-next-course {
  padding: 12px 24px;
  border-radius: var(--radius-lg);
  border: none;
  color: #000;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-block;
}

.btn-next-course:hover { transform: scale(1.03); }

/* ── Toast Notification ─────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  border: 1px solid rgba(0,0,0,0.1);
  border-radius: 100px;
  padding: 12px 24px;
  font-size: 0.88rem;
  font-weight: 500;
  color: #fff;
  z-index: 999;
  opacity: 0;
  transition: all 0.3s;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow);
}

.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast-success { background: var(--green); }

.site-footer {
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  padding: 28px 24px;
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-3);
}

/* ── Animations ─────────────────────────────────────────────── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes bounceIn {
  0%   { transform: scale(0.5); opacity: 0; }
  70%  { transform: scale(1.1); }
  100% { transform: scale(1); opacity: 1; }
}

.animated {
  animation: fadeIn 0.6s ease both;
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 768px) {
  .lesson-page {
    grid-template-columns: 1fr;
    padding: 20px 16px 120px;
  }

  #lesson-sidebar { display: none; }

  #lesson-content { padding: 24px 20px; }

  .comparison-grid { grid-template-columns: 1fr; }

  .rule-grid { grid-template-columns: 1fr; }

  .how-grid { grid-template-columns: 1fr 1fr; }

  #course-cards { grid-template-columns: 1fr; }

  .hero-stats { gap: 20px; }

  .lesson-footer-inner { flex-direction: column; gap: 10px; }

  .footer-prev, .footer-next { display: none; }

  .btn-complete { width: 100%; }

  #lesson-nav { padding: 10px 16px; }

  .lesson-nav-title { max-width: 180px; }

  .quiz-q-card { padding: 24px 20px; }

  .cost-row { grid-template-columns: 1fr; gap: 4px; }
}

@media (max-width: 480px) {
  .hero { padding: 40px 16px 40px; }
  .hero-stats { flex-direction: column; gap: 16px; }
  .how-grid { grid-template-columns: 1fr; }
}