/* =========================================================
   EBOOK STORE — GLOBAL STYLESHEET
   ========================================================= */

:root {
  /* Colors */
  --color-primary: #2D6A4F;
  --color-primary-dark: #1B4332;
  --color-secondary: #52B788;
  --color-secondary-light: #D8F3DC;
  --color-bg: #F8FBF9;
  --color-bg-alt: #EFF7F2;
  --color-surface: #FFFFFF;
  --color-text: #2B2D42;
  --color-text-muted: #5C6270;
  --color-border: #E3ECE6;
  --color-highlight: #FFF3CD;
  --color-danger: #D64545;

  /* Typography */
  --font-base: 'Be Vietnam Pro', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --fs-body: 17px;
  --lh-body: 1.7;

  /* Radius & Shadow */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 2px 8px rgba(43, 45, 66, 0.06);
  --shadow-md: 0 8px 24px rgba(43, 45, 66, 0.10);
  --shadow-lg: 0 16px 40px rgba(43, 45, 66, 0.16);

  /* Layout */
  --container-width: 1160px;
  --transition: all 0.25s ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-base);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

ul { list-style: none; }

button { font-family: inherit; cursor: pointer; border: none; background: none; }

h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; color: var(--color-primary-dark); }

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

.section { padding: 64px 0; }

.section-title {
  font-size: clamp(24px, 3vw, 34px);
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 40px;
  font-size: 16px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 16px;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
}

.btn-secondary:hover {
  background: var(--color-secondary);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--color-border);
  color: var(--color-text);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-block { width: 100%; }
.btn-lg { padding: 16px 32px; font-size: 17px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(248, 251, 249, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--color-primary-dark);
}

.logo-mark {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  object-fit: contain;
  display: flex;
  align-items: center;
  justify-content: center;
}

.main-nav ul {
  display: flex;
  align-items: center;
  gap: 32px;
}

.main-nav a {
  font-weight: 500;
  color: var(--color-text);
  transition: var(--transition);
  padding: 6px 0;
  position: relative;
}

.main-nav a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: var(--transition);
}

.main-nav a:hover { color: var(--color-primary); }
.main-nav a:hover::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: 14px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  z-index: 101;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-cta { display: none; }

/* ---------- Hero ---------- */
.hero {
  padding: 80px 0 60px;
  background: radial-gradient(circle at top right, var(--color-secondary-light) 0%, var(--color-bg) 60%);
}

.hero .container {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-content { min-width: 0; }

.hero-eyebrow {
  display: inline-block;
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  font-weight: 600;
  font-size: 14px;
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
}

.hero h1 {
  font-size: clamp(30px, 4.2vw, 48px);
  margin-bottom: 18px;
}

.hero h1 span { color: var(--color-primary); }

.hero-desc {
  font-size: 18px;
  color: var(--color-text-muted);
  margin-bottom: 30px;
  max-width: 520px;
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 28px; }

.hero-stats { display: flex; gap: 32px; flex-wrap: wrap; }

.hero-stats div strong {
  display: block;
  font-size: 24px;
  color: var(--color-primary-dark);
}

.hero-stats div span { color: var(--color-text-muted); font-size: 14px; }

/* Search box */
.search-box {
  display: flex;
  align-items: center;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: 6px 6px 6px 18px;
  max-width: 480px;
  border: 1px solid var(--color-border);
}

.search-box input {
  flex: 1;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 15px;
  padding: 10px 0;
  background: transparent;
  color: var(--color-text);
}

.search-box button {
  background: var(--color-primary);
  color: #fff;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: var(--transition);
}

.search-box button:hover { background: var(--color-primary-dark); }

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-visual .card-stack {
  position: relative;
  width: 100%;
  max-width: 360px;
}

.hero-visual img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.floating-badge {
  position: absolute;
  bottom: -18px;
  left: -18px;
  background: var(--color-surface);
  padding: 14px 18px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 600;
}

.floating-badge .dot {
  width: 10px; height: 10px; border-radius: 50%; background: var(--color-secondary);
}

/* ---------- Book Grid / Cards ---------- */
.book-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.book-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  border: 1px solid var(--color-border);
}

.book-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-secondary);
}

.book-card-cover {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--color-bg-alt);
}

.book-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.book-card:hover .book-card-cover img { transform: scale(1.05); }

.book-card-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: var(--color-primary);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: 999px;
}

.book-card-body {
  padding: 18px 20px 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.book-card-category {
  display: inline-block;
  align-self: flex-start;
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}

.book-card-title {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--color-text);
}

.book-card-title a {
  color: inherit;
  transition: var(--transition);
}

.book-card-title a:hover {
  color: var(--color-primary);
}

.book-card-desc {
  color: var(--color-text-muted);
  font-size: 14.5px;
  margin-bottom: 16px;
  flex: 1;
}

.book-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.book-price {
  font-size: 19px;
  font-weight: 800;
  color: var(--color-primary);
}

.book-price small {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: line-through;
}

/* ---------- Why Us ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.feature-item {
  background: var(--color-surface);
  padding: 28px 24px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: var(--transition);
}

.feature-item:hover { box-shadow: var(--shadow-md); transform: translateY(-4px); }

.feature-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  border-radius: var(--radius-md);
  background: var(--color-secondary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
}

.feature-item h3 { font-size: 17px; margin-bottom: 8px; }
.feature-item p { color: var(--color-text-muted); font-size: 15px; }

/* ---------- Newsletter / CTA band ---------- */
.cta-band {
  background: linear-gradient(120deg, var(--color-primary), var(--color-primary-dark));
  border-radius: var(--radius-lg);
  padding: 48px;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.cta-band h2 { color: #fff; font-size: 26px; margin-bottom: 8px; }
.cta-band p { color: rgba(255,255,255,0.85); }
.cta-band .btn-secondary { background: #fff; color: var(--color-primary-dark); }
.cta-band .btn-secondary:hover { background: var(--color-secondary-light); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255,255,255,0.85);
  padding: 60px 0 24px;
  margin-top: 40px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.2fr;
  gap: 32px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.12);
}

.footer-brand .logo { color: #fff; margin-bottom: 14px; }
.footer-brand p { font-size: 14.5px; color: rgba(255,255,255,0.65); max-width: 320px; }

.footer-col h4 {
  color: #fff;
  font-size: 15px;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.footer-col ul li { margin-bottom: 10px; }
.footer-col a { color: rgba(255,255,255,0.7); font-size: 14.5px; transition: var(--transition); }
.footer-col a:hover { color: var(--color-secondary); }

.footer-bottom {
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13.5px;
  color: rgba(255,255,255,0.55);
}

/* =========================================================
   LANDING PAGE (Book detail / SEO article)
   ========================================================= */

.breadcrumb {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.breadcrumb a { color: var(--color-primary); }
.breadcrumb span { margin: 0 6px; }

.book-hero {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 48px;
  padding: 40px 0 60px;
  align-items: start;
}

.book-hero-info { min-width: 0; }

.book-hero-cover img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%;
}

.book-hero-info .category-tag {
  display: inline-block;
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  font-size: 13px;
  font-weight: 700;
  padding: 5px 12px;
  border-radius: 999px;
  margin-bottom: 14px;
}

.book-hero-info h1 {
  font-size: clamp(26px, 3.4vw, 38px);
  margin-bottom: 14px;
}

.book-hero-info .lead {
  font-size: 18px;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.book-meta-row {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 24px;
  font-size: 14.5px;
  color: var(--color-text-muted);
}

.book-meta-row strong { color: var(--color-text); }

.rating-stars { color: #F4A100; letter-spacing: 2px; }

.price-box {
  display: flex;
  align-items: center;
  gap: 18px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.price-box .price-now { font-size: 32px; font-weight: 800; color: var(--color-primary); }
.price-box .price-old { font-size: 16px; text-decoration: line-through; color: var(--color-text-muted); }
.price-box .price-save {
  background: var(--color-highlight);
  color: #8a6100;
  font-size: 12.5px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
}

.book-hero-info .btn-cta {
  padding: 18px 40px;
  font-size: 18px;
  white-space: normal;
}

.trust-badges {
  display: flex;
  gap: 18px;
  margin-top: 20px;
  flex-wrap: wrap;
  font-size: 13.5px;
  color: var(--color-text-muted);
}

.trust-badges div { display: flex; align-items: center; gap: 6px; }

/* Article content */
.article-content {
  max-width: 760px;
  margin: 0 auto;
  padding-bottom: 40px;
}

.article-content h2 {
  font-size: 26px;
  margin: 40px 0 16px;
}

.article-content h3 {
  font-size: 20px;
  margin: 28px 0 12px;
  color: var(--color-text);
}

.article-content p { margin-bottom: 18px; color: var(--color-text); }

.article-content ul, .article-content ol {
  margin: 0 0 20px 0;
  padding-left: 4px;
}

.article-content li {
  margin-bottom: 10px;
  padding-left: 28px;
  position: relative;
}

.article-content ul li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

.article-content ol { counter-reset: item; }
.article-content ol li { counter-increment: item; }
.article-content ol li::before {
  content: counter(item);
  position: absolute;
  left: 0;
  top: -1px;
  width: 20px;
  height: 20px;
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

blockquote {
  border-left: 4px solid var(--color-secondary);
  background: var(--color-bg-alt);
  padding: 18px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
  color: var(--color-primary-dark);
  margin: 24px 0;
  font-size: 17.5px;
}

.highlight-box {
  background: var(--color-highlight);
  border: 1px solid #F3D983;
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 24px 0;
}

.highlight-box strong { color: #8a6100; }

.toc-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin: 32px 0;
}

.toc-box h3 { margin-bottom: 14px; font-size: 17px; }
.toc-box ol { padding-left: 0; }
.toc-box li { padding-left: 32px; }
.toc-box a { color: var(--color-text); transition: var(--transition); }
.toc-box a:hover { color: var(--color-primary); }

/* CTA Section (bottom of landing page) */
.cta-final {
  text-align: center;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border-radius: var(--radius-lg);
  padding: 56px 32px;
  color: #fff;
  margin: 48px 0;
}

.cta-final h2 { color: #fff; font-size: 28px; margin-bottom: 12px; }
.cta-final p { color: rgba(255,255,255,0.85); max-width: 520px; margin: 0 auto 28px; }

.cta-final .btn-cta {
  background: #fff;
  color: var(--color-primary-dark);
  font-size: 18px;
  padding: 18px 44px;
  white-space: normal;
}

.cta-final .btn-cta:hover { background: var(--color-highlight); }

/* =========================================================
   MODAL — QR PAYMENT
   ========================================================= */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(27, 67, 50, 0.55);
  backdrop-filter: blur(3px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 1000;
}

.modal-overlay.active {
  display: flex;
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.modal-box {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  max-width: 460px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.25s ease;
  position: relative;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

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

.modal-header h3 { font-size: 19px; }

.modal-close {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: var(--transition);
}

.modal-close:hover { background: var(--color-border); color: var(--color-text); }

.modal-body { padding: 24px; }

.order-summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  margin-bottom: 20px;
}

.order-summary .book-name { font-weight: 600; font-size: 15px; }
.order-summary .book-price-tag { font-weight: 800; color: var(--color-primary); font-size: 18px; }

.qr-frame {
  display: flex;
  justify-content: center;
  margin-bottom: 20px;
}

.qr-frame img {
  width: 220px;
  height: 220px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 10px;
  background: #fff;
}

.transfer-info {
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  margin-bottom: 20px;
}

.transfer-info dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px 14px;
  font-size: 14.5px;
}

.transfer-info dt { color: var(--color-text-muted); }
.transfer-info dd { font-weight: 700; text-align: right; }
.transfer-info dd.copyable { display: flex; align-items: center; justify-content: flex-end; gap: 8px; }

.copy-btn {
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 6px;
  transition: var(--transition);
}

.copy-btn:hover { background: var(--color-secondary); color: #fff; }

.modal-note {
  font-size: 13.5px;
  color: var(--color-text-muted);
  background: var(--color-highlight);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
}

.modal-actions {
  display: flex;
  gap: 12px;
}

.modal-actions .btn { flex: 1; }

.modal-success {
  text-align: center;
  padding: 12px 0;
}

.modal-success .success-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--color-secondary-light);
  color: var(--color-primary);
  font-size: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.modal-success h3 { margin-bottom: 8px; }
.modal-success p { color: var(--color-text-muted); font-size: 14.5px; margin-bottom: 20px; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--color-primary-dark);
  color: #fff;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  font-size: 14.5px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  z-index: 1100;
}

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

/* =========================================================
   SALES PAGE EXTRAS (comparison table, value stack, FAQ)
   ========================================================= */

.stat-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--color-secondary-light);
  color: var(--color-primary-dark);
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 999px;
  margin-bottom: 24px;
  font-size: 15px;
}

.table-scroll {
  overflow-x: auto;
  margin: 24px 0 32px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 560px;
  background: var(--color-surface);
}

.compare-table th, .compare-table td {
  padding: 14px 18px;
  text-align: left;
  font-size: 14.5px;
  border-bottom: 1px solid var(--color-border);
}

.compare-table thead th {
  background: var(--color-primary);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}

.compare-table tbody tr:nth-child(even) { background: var(--color-bg-alt); }
.compare-table tbody tr:last-child td { border-bottom: none; }
.compare-table td:first-child { font-weight: 600; color: var(--color-text); }
.compare-table td:last-child { color: var(--color-primary-dark); font-weight: 700; }

.value-stack-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 26px 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}

.value-stack-card .value-tag {
  display: inline-block;
  background: var(--color-highlight);
  color: #8a6100;
  font-size: 12.5px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 14px;
}

.value-stack-card h3 { font-size: 17px; margin-bottom: 16px; }

.value-stack-card ul { margin: 0; }

.value-stack-card li {
  padding-left: 28px;
  position: relative;
  margin-bottom: 12px;
  font-size: 15.5px;
  color: var(--color-text);
}

.value-stack-card li:last-child { margin-bottom: 0; }

.value-stack-card li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

.value-stack-card li strong { color: var(--color-primary-dark); }

.value-total {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: 26px 28px;
  text-align: center;
  margin-top: 12px;
}

.value-total .old {
  text-decoration: line-through;
  color: var(--color-text-muted);
  font-size: 16px;
  margin-right: 12px;
}

.value-total .new {
  font-size: 28px;
  font-weight: 800;
  color: var(--color-primary);
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  background: var(--color-surface);
}

.faq-item summary {
  padding: 16px 20px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  color: var(--color-text);
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: '+';
  font-size: 20px;
  line-height: 1;
  color: var(--color-primary);
  transition: var(--transition);
  flex-shrink: 0;
}

.faq-item[open] summary::after { transform: rotate(45deg); }

.faq-item .faq-answer {
  padding: 0 20px 18px;
  color: var(--color-text-muted);
  font-size: 15px;
  line-height: 1.7;
}

/* =========================================================
   CHECKOUT PAGE (standalone /thanh-toan/)
   ========================================================= */

.checkout-page {
  padding: 56px 0 90px;
  min-height: 60vh;
}

.checkout-card {
  max-width: 700px;
  margin: 0 auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 32px;
}

.checkout-card#stepQr {
  max-width: 900px;
}

.checkout-card h1 {
  font-size: 22px;
  text-align: center;
  margin-bottom: 24px;
}

.checkout-narrow {
  max-width: 420px;
  margin: 0 auto;
}

/* Step 2 — QR trái, thông tin phải */
.checkout-qr-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 32px;
  align-items: start;
}

.checkout-qr-col {
  position: sticky;
  top: 96px;
}

.checkout-qr-col .qr-frame { margin-bottom: 0; }
.checkout-qr-col .qr-frame img { width: 100%; height: auto; }

.checkout-info-col .order-summary { margin-bottom: 20px; }
.checkout-info-col .transfer-info { margin-bottom: 20px; }
.checkout-info-col .modal-note { margin-bottom: 20px; }

.checkout-product {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  margin-bottom: 24px;
}

.checkout-product img {
  width: 56px;
  height: 74px;
  object-fit: cover;
  border-radius: 8px;
  flex-shrink: 0;
}

.checkout-product .info strong {
  display: block;
  font-size: 15px;
  margin-bottom: 4px;
  color: var(--color-text);
}

.checkout-product .info .price {
  color: var(--color-primary);
  font-weight: 800;
  font-size: 17px;
}

.email-form label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 14.5px;
}

.email-form input[type="email"] {
  width: 100%;
  padding: 14px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text);
  margin-bottom: 6px;
  transition: var(--transition);
}

.email-form input[type="email"]:focus {
  outline: none;
  border-color: var(--color-secondary);
  box-shadow: 0 0 0 3px rgba(82, 183, 136, 0.18);
}

.field-hint {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 18px;
}

.field-error {
  color: var(--color-danger);
  font-size: 13.5px;
  margin: -2px 0 14px;
  display: none;
}

.field-error.show { display: block; }

.checkout-back {
  display: inline-block;
  margin-top: 14px;
  font-size: 14px;
  color: var(--color-text-muted);
  text-align: center;
  width: 100%;
}

.checkout-back:hover { color: var(--color-primary); }

.checkout-state {
  text-align: center;
  padding: 90px 20px;
}

.checkout-state .icon {
  font-size: 48px;
  margin-bottom: 18px;
}

.checkout-state h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.checkout-state p {
  color: var(--color-text-muted);
  max-width: 420px;
  margin: 0 auto 24px;
}

/* =========================================================
   RESPONSIVE
   ========================================================= */

@media (max-width: 960px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero-visual { order: -1; max-width: 320px; margin: 0 auto; }
  .book-hero { grid-template-columns: 1fr; }
  .book-hero-cover { max-width: 300px; margin: 0 auto; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .book-grid { grid-template-columns: repeat(2, 1fr); }

  .header-actions .btn { display: none; }
  .nav-toggle { display: flex; }

  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    padding: 12px 20px 20px;
  }

  .main-nav.nav-open { display: block; }

  .main-nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .main-nav a { display: block; padding: 12px 4px; }
  .main-nav a::after { display: none; }

  .nav-cta {
    display: block;
    margin-top: 10px;
    padding-top: 14px;
    border-top: 1px solid var(--color-border);
  }
}

@media (max-width: 768px) {
  .section { padding: 48px 0; }
  .cta-band { flex-direction: column; text-align: center; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

@media (max-width: 680px) {
  .checkout-qr-layout { grid-template-columns: 1fr; gap: 24px; }
  .checkout-qr-col { position: static; max-width: 220px; margin: 0 auto; }
}

@media (max-width: 520px) {
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-stats { justify-content: space-between; }
  .price-box { flex-direction: column; align-items: flex-start; }
  .modal-actions { flex-direction: column; }
  .book-grid { grid-template-columns: 1fr; gap: 16px; }
  .checkout-card { padding: 22px; }
}