/* ========================================
   AutoVocab Landing Page — Design Tokens & Styles
   ======================================== */

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

:root {
  /* Fonts */
  --font-heading: 'Inter', -apple-system, sans-serif;
  --font-body: 'Inter', -apple-system, sans-serif;

  /* Accent */
  --accent: #4F46E5;
  --accent-hover: #4338CA;
  --accent-light: #E0E7FF;
  --accent-warm: #F59E0B;
  --accent-warm-light: #FEF3C7;

  /* Status */
  --success: #16A34A;
  --error: #DC2626;
  --warning: #EA580C;
  --info: #2563EB;

  /* Neutral */
  --text-primary: #111827;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;
  --bg: #F8FAFC;
  --card-bg: #FFFFFF;
  --border: #E2E8F0;

  /* Spacing */
  --section-py: 96px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --card-padding: 28px 24px;
  --gap: 20px;

  /* Radius */
  --radius-btn: 8px;
  --radius-card: 12px;
  --radius-card-lg: 16px;
  --radius-badge: 20px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);

  /* Layout */
  --max-width: 1100px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-weight: 400;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========================================
   1. NAVBAR — Frosted Glass + CTA
   ======================================== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--card-bg);
  transition: background 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}
.navbar.scrolled {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.5);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
/* Logo — stylized A */
.logo {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 0;
}
.logo-a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  font-size: 18px;
  font-weight: 800;
  margin-right: 2px;
  letter-spacing: 0;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-primary);
  transition: color 0.2s;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
  transition: width 0.25s ease;
}
.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
}
/* CTA state — appears when scrolled past hero */
.nav-links a.nav-cta-link {
  transition: all 0.3s ease;
}
.navbar.past-hero .nav-links a.nav-cta-link {
  color: var(--accent);
  border: 1.5px solid var(--accent);
  padding: 6px 16px;
  border-radius: var(--radius-btn);
  font-weight: 600;
}
.navbar.past-hero .nav-links a.nav-cta-link::after {
  display: none;
}
.navbar.past-hero .nav-links a.nav-cta-link:hover {
  background: var(--accent);
  color: #fff;
  animation: none;
}

/* Dùng thử — slide in mượt khi hero CTA chìm dưới navbar.
   Element luôn render (để transition); ẩn = max-width 0 + margin-left -28px (huỷ flex gap). */
.nav-links a.nav-cta-trial {
  max-width: 0;
  padding-left: 0;
  padding-right: 0;
  margin-left: -28px;
  border-width: 0;
  opacity: 0;
  overflow: hidden;
  white-space: nowrap;
  pointer-events: none;
  transition:
    max-width 0.5s ease,
    padding 0.45s ease,
    margin-left 0.5s ease,
    border-width 0.3s ease,
    opacity 0.4s ease 0.1s,
    background 0.2s ease,
    color 0.2s ease;
}
.navbar.past-hero .nav-links a.nav-cta-trial {
  max-width: 200px;
  padding: 6px 16px;
  margin-left: 0;
  border-width: 1.5px;
  opacity: 1;
  pointer-events: auto;
  animation: ctaPulse 2.5s ease-in-out 0.55s infinite;
}
@keyframes ctaPulse {
  0% { box-shadow: 0 0 0 0 rgba(79,70,229,0.35); }
  70% { box-shadow: 0 0 0 7px rgba(79,70,229,0); }
  100% { box-shadow: 0 0 0 0 rgba(79,70,229,0); }
}
/* Hamburger — animates to X */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 36px;
  height: 36px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
  transform-origin: center;
}
.navbar.mobile-open .hamburger span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.navbar.mobile-open .hamburger span:nth-child(2) {
  opacity: 0;
}
.navbar.mobile-open .hamburger span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}
/* Mobile overlay backdrop */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  top: 64px;
  background: rgba(0,0,0,0.3);
  z-index: 99;
}
.navbar.mobile-open .nav-overlay {
  display: block;
}

/* ========================================
   2. HERO
   ======================================== */
.hero {
  text-align: center;
  padding: 100px 0 80px;
  background: linear-gradient(180deg, #EDEFFF 0%, #F4F0FF 40%, var(--bg) 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -180px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(79,70,229,0.06) 0%, transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute;
  bottom: -80px;
  left: -120px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(124,58,237,0.05) 0%, transparent 70%);
  pointer-events: none;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  background: rgba(79,70,229,0.08);
  border: 1px solid rgba(79,70,229,0.15);
  padding: 8px 20px;
  border-radius: var(--radius-badge);
  margin-bottom: 32px;
  letter-spacing: 0.04em;
  cursor: default;
  transition: all 0.25s ease;
}
.hero-badge:hover {
  background: rgba(79,70,229,0.14);
  border-color: rgba(79,70,229,0.3);
  box-shadow: 0 3px 6px rgba(79,70,229,0.4);
}
.badge-icon {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(42px, 7vw, 58px);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 28px;
  letter-spacing: -0.03em;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(135deg, var(--accent), #7C3AED);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 20px;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 40px;
  line-height: 1.7;
}
/* -- Hero Mockup (CSS-only Google Sheet simulation) -- */
.hero-mockup {
  max-width: 800px;
  margin: 0 auto 48px;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(79,70,229,0.12), 0 1px 3px rgba(0,0,0,0.08);
  border: 1px solid rgba(79,70,229,0.12);
  text-align: left;
  position: relative;
}
.mockup-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  background: #F1F5F9;
  border-bottom: 1px solid var(--border);
}
.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #CBD5E1;
}
.mockup-dot:nth-child(1) { background: #FCA5A5; }
.mockup-dot:nth-child(2) { background: #FCD34D; }
.mockup-dot:nth-child(3) { background: #86EFAC; }
.mockup-title {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  margin-left: 8px;
  flex: 1;
}
.mockup-status {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.mockup-status.visible {
  visibility: visible;
  opacity: 1;
}
.mockup-status .dot {
  display: inline-block;
  animation: dotBounce 1.2s ease-in-out infinite;
}
.mockup-status .dot:nth-child(2) { animation-delay: 0.15s; }
.mockup-status .dot:nth-child(3) { animation-delay: 0.3s; }
@keyframes dotBounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-4px); }
}
.mockup-sheet {
  background: #fff;
}
.mockup-row {
  display: grid;
  grid-template-columns: 30px 115px 120px 50px 180px 90px 1fr;
  border-bottom: 1px solid #E5E7EB;
}
.mockup-cell {
  padding: 8px 10px;
  font-size: 12px;
  border-right: 1px solid #F1F5F9;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  line-height: 1.4;
}
.mockup-header {
  background: #F8FAFC;
}
.mockup-header .mockup-cell {
  font-weight: 700;
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 6px 10px;
}
.mockup-data .cell-word {
  font-weight: 600;
  color: var(--accent);
}
.mockup-data .cell-pron {
  font-style: italic;
  color: var(--text-muted);
}
.mockup-data .cell-pos {
  color: #7C3AED;
  font-weight: 600;
  font-style: italic;
}
.mockup-data .cell-mean {
  color: var(--text-primary);
  font-weight: 500;
}

/* Typing cursor */
.mockup-typing {
  display: inline-block;
  overflow: hidden;
  white-space: nowrap;
  border-right: 2px solid var(--accent);
  width: 0;
  transition: none;
}
@keyframes blink {
  50% { border-color: transparent; }
}

/* AI fill — JS adds this class */
.mockup-cell-hidden {
  opacity: 0;
}
.mockup-cell-fill {
  animation: aiFill 0.35s ease forwards;
}
@keyframes aiFill {
  0% { opacity: 0; transform: translateY(4px); }
  100% { opacity: 1; transform: translateY(0); }
}
.btn-primary {
  display: inline-block;
  padding: 14px 36px;
  background: var(--accent);
  color: #fff;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 4px 14px rgba(79,70,229,0.3);
}
.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(79,70,229,0.4);
}
.btn-outline {
  display: inline-block;
  padding: 14px 36px;
  background: transparent;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(79,70,229,0.04);
}

.btn-secondary {
  display: inline-block;
  padding: 14px 32px;
  background: transparent;
  color: var(--accent);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  border: 1.5px solid var(--accent);
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}
.btn-secondary:hover {
  background: var(--accent);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(79,70,229,0.25);
}

.hero-cta {
  display: inline-flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}
.hero-cta .btn-primary,
.hero-cta .btn-secondary {
  text-decoration: none;
}
@media (max-width: 480px) {
  .hero-cta {
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }
  .hero-cta .btn-primary,
  .hero-cta .btn-secondary {
    text-align: center;
  }
}

/* ========================================
   3. FEATURES
   ======================================== */
.features {
  padding: var(--section-py) 0;
}
.section-title {
  font-family: var(--font-heading);
  font-size: 32px;
  font-weight: 800;
  text-align: center;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.section-subtitle {
  font-size: 17px;
  font-weight: 500;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 48px;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--gap);
}
.feature-card {
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-card-lg);
  padding: var(--card-padding);
  box-shadow: 0 1px 4px rgba(0,0,0,0.1);
  transition: var(--transition);
}
.feature-card:hover {
  box-shadow: 0 4px 8px rgba(79,70,229,0.65);
}
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-card);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 16px;
  background: var(--accent-light);
  color: var(--accent);
}
.feature-card h3 {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ========================================
   4. HOW IT WORKS
   ======================================== */
.how-section {
  padding: var(--section-py) 0;
  text-align: center;
}
.steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
  max-width: 900px;
  margin: 0 auto;
}
.step {
  text-align: center;
  flex: 1;
  position: relative;
  padding: 0 24px;
}
.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 20px;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  box-shadow: 0 4px 12px rgba(79,70,229,0.25);
  position: relative;
  z-index: 1;
}
.step:not(:last-child)::after {
  content: '';
  position: absolute;
  top: 24px;
  left: calc(50% + 32px);
  right: calc(-50% + 32px);
  height: 3px;
  background: var(--accent);
  opacity: 0.35;
  border-radius: 2px;
}
.step h4 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
}
.step p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 220px;
  margin: 0 auto;
}

/* ========================================
   5. PRICING — Mode-first tabs (pricing.html)
   ======================================== */
.pricing {
  padding: var(--section-py) 0;
}
.mode-tabs {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.mode-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 16px 24px;
  background: var(--card-bg);
  border: 2px solid var(--border);
  border-radius: var(--radius-card);
  cursor: pointer;
  transition: var(--transition, all 0.3s ease);
  font-family: var(--font-body);
  position: relative;
  min-width: 160px;
}
.mode-tab:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}
.mode-tab.active {
  border-color: var(--accent);
  background: var(--accent-light);
  box-shadow: var(--shadow-md);
}
.mode-tab-icon { font-size: 28px; }
.mode-tab-name { font-size: 15px; font-weight: 700; color: var(--text-primary); }
.mode-tab-desc { font-size: 12px; color: var(--text-secondary); }
.mode-tab-badge {
  position: absolute;
  top: -10px;
  right: -8px;
  background: var(--accent);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-badge);
}
.mode-description {
  text-align: center;
  margin-bottom: 32px;
}
.mode-description p {
  font-size: 15px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}
.plan-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  max-width: 720px;
  margin: 0 auto 32px;
}
.plan-card {
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-card-lg);
  padding: 32px 24px;
  text-align: center;
  position: relative;
  transition: var(--transition, all 0.3s ease);
}
.plan-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.plan-card.recommended {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
  transform: scale(1.04);
  background: linear-gradient(180deg, #FAFAFF 0%, #fff 100%);
}
.plan-card.recommended:hover {
  transform: scale(1.04) translateY(-4px);
}
.plan-badge {
  position: absolute;
  top: -11px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 14px;
  border-radius: var(--radius-badge);
  white-space: nowrap;
}
.plan-card h4 {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
  margin-top: 4px;
}
.plan-price {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
}
.plan-price-value {
  font-size: 36px;
  font-weight: 700;
  color: var(--accent);
}
.plan-price-unit {
  font-size: 16px;
  color: var(--text-muted);
}
.plan-per {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.plan-savings {
  display: inline-block;
  background: var(--accent-warm-light);
  color: #92400E;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: var(--radius-badge);
  margin-bottom: 16px;
}
.plan-card .btn-primary,
.plan-card .btn-outline {
  width: 100%;
  padding: 12px 24px;
  display: block;
}
.plan-card .btn-outline {
  background: transparent;
  color: var(--accent);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  border: 1.5px solid var(--accent);
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: all 0.2s ease;
}
.plan-card .btn-outline:hover {
  background: var(--accent-light);
}
.mode-features {
  max-width: 480px;
  margin: 0 auto;
  text-align: center;
}
.mode-features h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.mode-features ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}
.mode-features li {
  font-size: 14px;
  padding: 6px 14px;
  border-radius: var(--radius-badge);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.mode-features li.included {
  background: #DCFCE7;
  color: #15803D;
}
.mode-features li.excluded {
  background: #F3F4F6;
  color: var(--text-muted);
  text-decoration: line-through;
}

/* ========================================
   6. PRICING PREVIEW (index.html mini section)
   ======================================== */
.pricing-preview {
  padding: var(--section-py) 0;
}
.pricing-mini-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
  max-width: 800px;
  margin: 0 auto;
}
.pricing-mini-card {
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-card-lg);
  padding: var(--card-padding);
  text-align: center;
  transition: var(--transition);
}
.pricing-mini-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.pricing-mini-card.highlight {
  border-color: var(--accent);
}
.pricing-mini-card h4 {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px;
}
.pricing-mini-price {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}
.pricing-mini-per {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
}
.pricing-mini-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 20px;
}
.pricing-mini-card .btn-primary,
.pricing-mini-card .btn-outline {
  width: 100%;
  padding: 10px 20px;
  display: block;
  font-size: 15px;
}
.pricing-detail-link {
  display: block;
  text-align: center;
  margin-top: 32px;
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  transition: color 0.2s;
}
.pricing-detail-link:hover {
  color: var(--accent-hover);
}

/* ========================================
   7. FAQ
   ======================================== */
.faq {
  padding: var(--section-py) 0;
}
.faq-list {
  max-width: 700px;
  margin: 0 auto;
}
.faq-item {
  border-bottom: 1px solid var(--border);
}
.faq-item:first-child {
  border-top: 1px solid var(--border);
}
.faq-question {
  width: 100%;
  padding: 20px 0;
  background: none;
  border: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  gap: 16px;
}
.faq-question:hover {
  color: var(--accent);
}
.faq-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
  color: var(--text-muted);
}
.faq-item.open .faq-icon {
  transform: rotate(180deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1), padding 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}
.faq-answer-inner {
  padding: 0 0 20px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ========================================
   8. FOOTER
   ======================================== */
.site-footer {
  background: var(--text-primary);
  color: #fff;
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
}
.footer-brand .logo {
  color: #fff;
  font-size: 22px;
  display: inline-flex;
  margin-bottom: 8px;
}
.footer-brand .logo-a {
  background: rgba(255,255,255,0.2);
  font-size: 16px;
  width: 26px;
  height: 26px;
}
.footer-brand p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}
.footer-links h4,
.footer-contact h4 {
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
  color: var(--text-muted);
}
.footer-links a {
  display: block;
  font-size: 15px;
  color: rgba(255,255,255,0.8);
  padding: 4px 0;
  transition: color 0.2s;
}
.footer-links a:hover {
  color: #fff;
}
.footer-contact p,
.footer-contact a {
  font-size: 14px;
  color: rgba(255,255,255,0.8);
  line-height: 1.8;
}
.footer-contact a:hover {
  color: #fff;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 20px 0;
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
}

/* ========================================
   RESPONSIVE — Tablet < 768px
   ======================================== */
@media (max-width: 768px) {
  :root {
    --section-py: 56px;
  }

  /* Navbar mobile */
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--card-bg);
    flex-direction: column;
    padding: 16px 24px;
    gap: 0;
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--border);
  }
  .nav-links a {
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
  }
  .nav-links a:last-child {
    border-bottom: none;
  }
  .navbar.past-hero .nav-links a.nav-cta-link {
    border: none;
    padding: 12px 0;
    border-radius: 0;
  }
  /* Mobile: Dùng thử always visible inside hamburger menu, no scroll animation */
  .nav-links a.nav-cta-trial,
  .navbar.past-hero .nav-links a.nav-cta-trial {
    opacity: 1;
    max-width: none;
    padding: 12px 0;
    margin: 0;
    border: 0;
    border-bottom: 1px solid var(--border);
    animation: none;
    pointer-events: auto;
    color: var(--accent);
    font-weight: 600;
  }
  .navbar.mobile-open .nav-links {
    display: flex;
  }
  .hamburger {
    display: flex;
  }

  /* Hero */
  .hero {
    padding: 60px 0 48px;
  }
  .hero h1 {
    font-size: 32px;
  }
  .hero p {
    font-size: 16px;
  }

  /* Mockup — hide less important columns on tablet */
  .mockup-row {
    grid-template-columns: 36px 90px 100px 50px 1fr;
  }
  .cell-mean,
  .cell-ex {
    display: none;
  }

  /* Features */
  .features-grid {
    grid-template-columns: 1fr;
  }

  /* Steps */
  .steps {
    flex-direction: column;
    gap: 24px;
  }
  .step:not(:last-child)::after {
    display: none;
  }

  /* Pricing page */
  .mode-tabs {
    flex-direction: column;
    align-items: center;
  }
  .mode-tab {
    width: 100%;
    max-width: 300px;
    flex-direction: row;
    gap: 12px;
    padding: 12px 16px;
  }
  .plan-grid {
    grid-template-columns: 1fr;
    max-width: 320px;
    margin-left: auto;
    margin-right: auto;
  }
  .plan-card.recommended {
    transform: none;
  }

  /* Mini pricing */
  .pricing-mini-grid {
    grid-template-columns: 1fr;
    max-width: 320px;
    margin-left: auto;
    margin-right: auto;
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* ========================================
   RESPONSIVE — Small phone < 480px
   ======================================== */
@media (max-width: 480px) {
  :root {
    --section-py: 40px;
  }

  .hero {
    padding: 48px 0 40px;
  }
  .hero h1 {
    font-size: 28px;
  }
  .hero p {
    font-size: 15px;
  }
  /* Mockup — minimal on small phone */
  .mockup-row {
    grid-template-columns: 30px 80px 90px 1fr;
  }
  .cell-pos,
  .cell-mean,
  .cell-ex {
    display: none;
  }
  .mockup-cell {
    padding: 6px 8px;
    font-size: 11px;
  }

  .pricing-mini-card {
    padding: 20px 16px;
  }
}

/* ========================================
   SCROLL ANIMATIONS
   ======================================== */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }

/* ========================================
   DECORATIVE — section dividers
   ======================================== */
.features,
.how-section {
  position: relative;
}
.features::before,
.how-section::before {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
  margin: 0 auto 24px;
  opacity: 0.5;
}

/* ========================================
   ENHANCED — card & interactive polish
   ======================================== */
.feature-card {
  backdrop-filter: blur(4px);
}