/* Age Tabs, Vocab, 5 Steps, Stories, Redesigned Pricing + Buy CTA & Web Checkout Modal (< 120 LOC) */
.age-tabs { display: flex; justify-content: center; gap: 12px; margin-bottom: 24px; flex-wrap: wrap; }
.age-tab { padding: 11px 22px; border-radius: 999px; border: 2px solid var(--border); background: var(--bg-alt); color: var(--ink-soft); font-family: inherit; font-size: 0.96rem; font-weight: 800; cursor: pointer; white-space: nowrap; transition: all 0.15s ease; }
.age-tab.active { background: var(--primary); color: #FFFFFF; border-color: var(--primary); box-shadow: 0 6px 18px rgba(217, 107, 39, 0.22); }
.age-showcase { display: grid; grid-template-columns: 1fr 1.15fr; gap: 28px; background: var(--bg-alt); border: 2px solid var(--border); border-radius: var(--radius-lg); padding: 24px; align-items: center; }
.age-scene-img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border-radius: var(--radius-md); border: 1.5px solid var(--border); display: block; }
.age-meta-badge { display: inline-block; background: var(--green-soft); color: var(--green); font-weight: 800; font-size: 0.8rem; padding: 5px 12px; border-radius: 999px; margin-bottom: 8px; width: fit-content; }
.age-quote-box { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-md); padding: 16px; margin: 12px 0; }

.vocab-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 22px; }
.vocab-card { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-md); padding: 16px; display: flex; gap: 14px; align-items: flex-start; }
.vocab-thumb { width: 78px; height: 78px; border-radius: 12px; object-fit: cover; flex-shrink: 0; border: 1px solid var(--border); }
.vocab-info h4 { font-size: 1.12rem; font-weight: 800; color: var(--primary); }
.vocab-info .vocab-vi { font-size: 0.86rem; font-weight: 700; color: var(--ink); margin-bottom: 6px; }

.steps-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.step-card { background: var(--bg-alt); border: 1.5px solid var(--border); border-radius: var(--radius-md); padding: 20px 16px; text-align: center; }
.step-num { width: 36px; height: 36px; border-radius: 50%; background: var(--primary); color: #FFFFFF; font-weight: 800; display: inline-flex; align-items: center; justify-content: center; margin-bottom: 10px; }
.step-card h3 { font-size: 1rem; font-weight: 800; margin-bottom: 6px; }
.step-card p { font-size: 0.88rem; color: var(--ink-soft); }

.story-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.story-card { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; display: flex; flex-direction: column; }
.story-card-img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; display: block; border-bottom: 1px solid var(--border); }
.story-card-body { padding: 20px; display: flex; flex-direction: column; gap: 8px; flex: 1; }

/* Redesigned Pricing Cards with Clean Stacked Rows, Prominent Discounts & Full-Width CTA Buy Buttons */
.pricing-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; align-items: stretch; }
.price-card { background: var(--bg-alt); border: 2px solid var(--border); border-radius: var(--radius-lg); padding: 22px 18px; display: flex; flex-direction: column; justify-content: space-between; position: relative; transition: transform 0.15s ease; }
.price-card.featured { background: #FFFBF2; border: 2.5px solid var(--primary); box-shadow: 0 16px 36px rgba(217, 107, 39, 0.14); }
.price-card.lifetime-card { background: #F7FBF8; border: 2px solid #8CC5A6; }

.price-top-badges { display: flex; align-items: center; justify-content: space-between; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.discount-ribbon { display: inline-block; background: #D94E1F; color: #FFFFFF; font-weight: 800; font-size: 0.76rem; padding: 4px 10px; border-radius: 999px; letter-spacing: 0.02em; text-transform: uppercase; box-shadow: 0 4px 10px rgba(217, 78, 31, 0.25); }
.discount-ribbon.green-ribbon { background: var(--green); box-shadow: 0 4px 10px rgba(45, 106, 79, 0.22); }

.price-title { font-size: 1.2rem; font-weight: 800; color: var(--ink); margin-bottom: 8px; }
.price-old-row { min-height: 26px; display: flex; align-items: center; gap: 8px; margin-bottom: 2px; flex-wrap: wrap; }
.price-strike { text-decoration: line-through; color: var(--ink-muted); font-size: 0.9rem; font-weight: 700; }
.price-save-tag { font-size: 0.76rem; font-weight: 800; color: #B84218; background: #FFE6D9; padding: 2px 8px; border-radius: 6px; }

.price-main-row { display: flex; align-items: baseline; gap: 4px; margin-bottom: 6px; }
.price-amount { font-size: 1.95rem; font-weight: 800; color: var(--ink); line-height: 1.1; letter-spacing: -0.02em; }
.price-unit { font-size: 0.92rem; font-weight: 700; color: var(--ink-soft); }

.price-sub-line { display: block; font-size: 0.85rem; font-weight: 700; color: var(--primary); background: var(--primary-soft); padding: 6px 10px; border-radius: 8px; margin-bottom: 14px; line-height: 1.35; }
.price-card:not(.featured):not(.lifetime-card) .price-sub-line { color: var(--ink-soft); background: #F3E9D8; }
.price-card.lifetime-card .price-sub-line { color: var(--green); background: var(--green-soft); }

.price-features { list-style: none; display: grid; gap: 8px; margin: 0 0 16px; padding-top: 12px; border-top: 1px dashed var(--border); font-size: 0.86rem; color: var(--ink-soft); }
.price-features li { display: flex; align-items: flex-start; gap: 8px; line-height: 1.45; }
.price-features li strong { color: var(--ink); }
.price-check { color: var(--green); font-weight: 900; flex-shrink: 0; }

.price-cta-wrap { margin-top: auto; padding-top: 14px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 6px; text-align: center; }
.price-cta-btn { width: 100%; justify-content: center; padding: 12px 14px; font-size: 0.92rem; font-weight: 800; }
.btn-green { background: var(--green); color: #FFFFFF; box-shadow: 0 6px 16px rgba(45, 106, 79, 0.25); border: none; }
.btn-green:hover { background: #23533D; transform: translateY(-1px); }
.price-cta-note { font-size: 0.74rem; color: var(--ink-muted); font-weight: 600; line-height: 1.3; }

.app-sync-banner { margin-top: 22px; background: var(--bg-alt); border: 1.5px solid var(--border); border-radius: var(--radius-md); padding: 16px 20px; display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* Web Direct Checkout Modal (VietQR / International Card + App Sync) */
.checkout-modal { position: fixed; inset: 0; background: rgba(44, 30, 22, 0.65); backdrop-filter: blur(4px); z-index: 200; display: none; align-items: center; justify-content: center; padding: 16px; overflow-y: auto; }
.checkout-modal.open { display: flex; }
.checkout-dialog { background: var(--surface); border: 2px solid var(--border); border-radius: var(--radius-lg); max-width: 540px; width: 100%; padding: 24px 22px; position: relative; box-shadow: 0 24px 56px rgba(44, 30, 22, 0.28); }
.modal-close { position: absolute; top: 14px; right: 16px; background: var(--bg-alt); border: 1.5px solid var(--border); width: 34px; height: 34px; border-radius: 50%; font-weight: 800; cursor: pointer; }
.checkout-form { display: grid; gap: 12px; margin-top: 12px; }
.checkout-input { width: 100%; padding: 11px 14px; border-radius: 12px; border: 1.5px solid var(--border); font-family: inherit; font-size: 0.95rem; }
.qr-box { display: grid; grid-template-columns: 150px 1fr; gap: 14px; align-items: center; background: #FFFFFF; border: 1.5px solid var(--border); border-radius: 14px; padding: 12px; margin-top: 10px; }
.qr-box img { width: 150px; height: auto; border-radius: 8px; display: block; border: 1px solid var(--border); }

.faq-list { max-width: 820px; margin: 0 auto; display: grid; gap: 12px; }
.faq-list details { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-md); padding: 16px 20px; }
.faq-list summary { font-weight: 800; cursor: pointer; }
.faq-list details p { margin-top: 10px; color: var(--ink-soft); }
.site-footer { padding: 36px 0 48px; border-top: 1px solid var(--border); text-align: center; color: var(--ink-soft); font-size: 0.9rem; }

@media (max-width: 1120px) {
  .nav-links { gap: 11px; }
  .nav-links a { font-size: 0.84rem; }
  .brand-sub { display: none; }
}
@media (max-width: 1040px) { .pricing-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 960px) {
  .hero-grid, .age-showcase, .story-grid { grid-template-columns: 1fr; }
  .vocab-grid, .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
}
@media (max-width: 580px) {
  .vocab-grid, .pricing-grid, .steps-grid, .qr-box { grid-template-columns: 1fr; }
}