:root {
  --bg: #f6f8fa; --card: #ffffff; --ink: #0b1220; --muted: #5b6577; --line: #e3e8ef;
  --accent: #059669; --accent-ink: #ffffff; --accent-soft: #d1fae5; --warn: #b45309; --warn-bg: #fef3c7;
  --alt: #eef2f6; --term: #0b1220; --shadow: 0 6px 24px rgba(15, 23, 42, .08);
  --radius: 16px;
}
:root[data-theme="dark"] {
  --bg: #0b1220; --card: #131c2e; --ink: #e8edf5; --muted: #98a4b8; --line: #243049;
  --accent: #34d399; --accent-ink: #052e1f; --accent-soft: #0f3d2e; --warn: #fbbf24; --warn-bg: #3a2c0a;
  --alt: #0f1828; --term: #060b16; --shadow: 0 6px 24px rgba(0, 0, 0, .4);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1220; --card: #131c2e; --ink: #e8edf5; --muted: #98a4b8; --line: #243049;
    --accent: #34d399; --accent-ink: #052e1f; --accent-soft: #0f3d2e; --warn: #fbbf24; --warn-bg: #3a2c0a;
    --alt: #0f1828; --term: #060b16; --shadow: 0 6px 24px rgba(0, 0, 0, .4);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--ink); }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-underline-offset: 3px; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .5em; }
h1 { font-size: clamp(1.8rem, 5vw, 2.8rem); }
h2 { font-size: clamp(1.4rem, 3.5vw, 1.9rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1em; }
.muted { color: var(--muted); } .small { font-size: .875rem; } .mt { margin-top: 2.5rem; } .grow { flex: 1; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.skip { position: absolute; left: -999px; } .skip:focus { left: 8px; top: 8px; background: var(--card); padding: 8px 12px; z-index: 99; }
.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.narrow { max-width: 820px; }
.section { padding: 40px 0; } .section.alt { background: var(--alt); }
.section-title { text-align: center; margin-bottom: 1.2em; }
.section-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.section-head .section-title { text-align: left; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: .8rem; font-weight: 700; color: var(--accent); margin-bottom: .6em; }
.lead { font-size: 1.1rem; }
.big { font-size: 2.2rem; margin-bottom: .2em; }
.prose h3 { margin-top: 1.4em; } .prose ul { padding-left: 1.3em; } .prose li { margin: .3em 0; }
.prose blockquote { margin: 1em 0; padding: .6em 1em; border-left: 4px solid var(--accent); background: var(--accent-soft); border-radius: 8px; }
.prose blockquote p { margin: 0; }
code { background: var(--alt); padding: .1em .35em; border-radius: 6px; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-size: 1.15rem; }
.brand-text b { color: var(--accent); }
.nav { display: flex; gap: 4px; }
.nav a { padding: 10px 12px; border-radius: 10px; text-decoration: none; color: var(--ink); font-weight: 500; min-height: 44px; display: inline-flex; align-items: center; }
.nav a:hover, .nav a.active { background: var(--accent-soft); color: var(--accent); }
.header-actions { display: flex; gap: 6px; align-items: center; }
.icon-btn { position: relative; min-width: 44px; min-height: 44px; border: 1px solid var(--line); background: var(--card); color: var(--ink); border-radius: 12px; font-size: 1.1rem; cursor: pointer; display: inline-flex; align-items: center; justify-content: center; text-decoration: none; }
.badge { position: absolute; top: -6px; right: -6px; background: var(--accent); color: var(--accent-ink); font-size: .72rem; font-weight: 700; min-width: 20px; height: 20px; border-radius: 10px; display: grid; place-items: center; padding: 0 5px; }
.badge[hidden] { display: none; }
.hamburger { display: none; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 44px; padding: 0 18px; border-radius: 12px; border: 2px solid var(--accent); background: var(--accent); color: var(--accent-ink); font: inherit; font-weight: 700; cursor: pointer; text-decoration: none; transition: transform .1s, filter .15s; }
.btn:hover { filter: brightness(1.08); } .btn:active { transform: scale(.97); }
.btn-ghost { background: transparent; color: var(--accent); }
.btn-lg { min-height: 52px; padding: 0 26px; font-size: 1.05rem; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

/* Cards */
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.pad { padding: 20px; }
.grid-3 { display: grid; gap: 16px; grid-template-columns: repeat(3, 1fr); }
.grid-cards { display: grid; gap: 20px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.grid-cards [hidden] { display: none; }
.service-card { display: flex; flex-direction: column; }
.card-img { position: relative; display: block; }
.card-img img { width: 100%; aspect-ratio: 8 / 5; object-fit: cover; }
.card-body { padding: 16px; display: flex; flex-direction: column; gap: 4px; flex: 1; }
.card-body h3 a { color: var(--ink); text-decoration: none; }
.card-meta { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; margin-top: auto; }
.card-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.card-actions .btn { flex: 1; }
.price { font-size: 1.25rem; font-weight: 800; color: var(--accent); }
.price.big { font-size: 2.2rem; }
.old { text-decoration: line-through; color: var(--muted); }
.chip { display: inline-block; font-size: .75rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); }
.card-img .chip { position: absolute; top: 10px; left: 10px; background: rgba(11, 18, 32, .75); color: #fff; }
.chip.save { background: var(--warn-bg); color: var(--warn); }

/* Hero */
.hero { padding: 56px 0 40px; background: radial-gradient(900px 400px at 85% 0%, var(--accent-soft), transparent 70%); }
.hero-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 32px; align-items: center; }
.hero h1 { font-size: clamp(2.2rem, 6vw, 3.6rem); }
.grad { background: linear-gradient(90deg, var(--accent), #0ea5e9); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 8px; }
.terminal { background: var(--term); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; border: 1px solid var(--line); }
.term-bar { display: flex; align-items: center; gap: 7px; padding: 10px 14px; background: #1b2438; color: #8b97ad; font-size: .8rem; }
.term-bar i { width: 11px; height: 11px; border-radius: 50%; background: #ef4444; } .term-bar i:nth-child(2) { background: #f59e0b; } .term-bar i:nth-child(3) { background: #22c55e; }
.term-bar span { margin-left: auto; }
.term-out { margin: 0; padding: 18px; min-height: 230px; color: #34d399; font: 15px/1.6 ui-monospace, Consolas, monospace; white-space: pre-wrap; }

.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.steps li { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 12px; text-align: center; font-weight: 700; position: relative; }
.steps li b { display: grid; place-items: center; width: 40px; height: 40px; margin: 0 auto 8px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); }
.steps li:not(:last-child)::after { content: "→"; position: absolute; right: -14px; top: 50%; color: var(--muted); z-index: 1; }
.pack-teaser { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: center; }
.pack-teaser img { border-radius: var(--radius); box-shadow: var(--shadow); }

/* Filters */
.filters { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 8px; align-items: center; }
.filters input, .filters select, .form input, .form select, .form textarea, .coupon input, .form-row input { min-height: 44px; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; width: 100%; }
.filters input[type=search] { flex: 1 1 260px; width: auto; }
.filters select { width: auto; }
.chips { display: flex; gap: 6px; flex-wrap: wrap; }
.chip-btn { min-height: 44px; padding: 0 16px; border-radius: 999px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; cursor: pointer; }
.chip-btn.active { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 700; }
.empty { padding: 24px; text-align: center; }

/* Detail */
.detail { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; align-items: center; margin-bottom: 24px; }
.detail-media img { border-radius: var(--radius); box-shadow: var(--shadow); width: 100%; }
.big-meta { margin: 8px 0 12px; justify-content: flex-start; gap: 14px; }
.reviews { display: grid; gap: 12px; margin-bottom: 32px; }
.review { margin: 0; } .review blockquote { margin: .4em 0; } .stars { color: #f59e0b; letter-spacing: 2px; }
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.compare .best { border: 2px solid var(--accent); }
.tbl { width: 100%; border-collapse: collapse; } .tbl td { padding: 8px 0; border-bottom: 1px solid var(--line); } .tbl .r { text-align: right; } .tbl .total td { font-weight: 800; border-bottom: 0; }

/* Find your fix */
.fix-card { margin-top: 12px; }
.progress { height: 8px; background: var(--alt); border-radius: 999px; overflow: hidden; margin-bottom: 14px; }
#fix-bar { height: 100%; width: 33%; background: var(--accent); transition: width .3s; }
.opts { display: grid; gap: 10px; margin: 14px 0 18px; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.opt { min-height: 56px; padding: 10px 14px; text-align: left; border: 2px solid var(--line); background: var(--card); color: var(--ink); border-radius: 14px; font: inherit; font-weight: 600; cursor: pointer; transition: border-color .15s, transform .1s; }
.opt:hover { border-color: var(--accent); transform: translateY(-2px); }
.result-list { display: grid; gap: 12px; margin: 14px 0; }
.result-item { display: flex; gap: 16px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.result-item .card-actions { margin: 0; }
.check { display: flex; gap: 10px; align-items: center; min-height: 44px; cursor: pointer; }
.check input { width: 22px; height: 22px; accent-color: var(--accent); }

/* Cart */
.demo-banner { background: var(--warn-bg); color: var(--warn); border: 1px dashed var(--warn); border-radius: 12px; padding: 10px 14px; font-weight: 700; margin-bottom: 16px; }
.demo-banner.small { font-size: .85rem; font-weight: 600; margin: 4px 0 12px; }
.cart-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 20px; align-items: start; }
.cart-list { display: grid; gap: 10px; }
.cart-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.qty { display: flex; align-items: center; gap: 4px; }
.qty button { width: 44px; height: 44px; border-radius: 12px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font-size: 1.2rem; cursor: pointer; }
.qty span { min-width: 28px; text-align: center; font-weight: 700; }
.line-total { font-weight: 800; min-width: 90px; text-align: right; }
.summary { position: sticky; top: 80px; }
.coupon { display: flex; gap: 8px; } .coupon input { text-transform: uppercase; }
.sum-line { display: flex; justify-content: space-between; padding: 6px 0; } .sum-line.total { font-size: 1.3rem; font-weight: 800; border-top: 1px solid var(--line); margin-top: 6px; padding-top: 12px; }
.form { display: grid; gap: 12px; margin-top: 12px; } .form label { display: grid; gap: 4px; font-weight: 600; font-size: .9rem; }
fieldset.pay { border: 1px solid var(--line); border-radius: 12px; padding: 8px 12px; } .pay legend { font-weight: 700; padding: 0 6px; }
.pay .check { font-weight: 500; }
.fake-qr { margin: 8px auto; width: 150px; height: 150px; background: repeating-conic-gradient(#0b1220 0 25%, #fff 0 50%) 0 0 / 30px 30px; border: 6px solid #fff; border-radius: 8px; display: grid; place-items: center; color: #fff; text-align: center; }
.fake-qr div { background: #0b1220; padding: 4px 10px; border-radius: 6px; font-weight: 800; } .fake-qr small { background: #0b1220; font-size: .65rem; padding: 2px 6px; }
.empty-cart, .success { text-align: center; padding: 40px 20px; }
.order-code { font-size: 2.4rem; font-weight: 900; letter-spacing: .06em; color: var(--accent); margin: 0 0 8px; }
.form-row { display: flex; gap: 10px; }

/* Timeline */
.timeline { list-style: none; padding: 0; margin: 20px 0; display: grid; gap: 18px; }
.timeline li { display: flex; align-items: center; gap: 12px; color: var(--muted); font-weight: 600; }
.timeline li span { width: 22px; height: 22px; border-radius: 50%; border: 3px solid var(--line); background: var(--card); }
.timeline li.done { color: var(--ink); } .timeline li.done span { background: var(--accent); border-color: var(--accent); }
.timeline li.now { color: var(--accent); } .timeline li.now span { border-color: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }

/* About / Contact / FAQ */
.team { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; }
.member { text-align: center; } .avatar { width: 72px; height: 72px; border-radius: 50%; margin: 0 auto 10px; display: grid; place-items: center; font-size: 1.8rem; font-weight: 800; background: linear-gradient(135deg, var(--accent), #0ea5e9); color: #fff; }
.role { color: var(--accent); font-weight: 700; font-size: .9rem; }
.ai-list { padding-left: 1.2em; } .ai-list li { margin: .5em 0; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; align-items: start; }
.contact-list { list-style: none; padding: 0; display: grid; gap: 14px; } .contact-list li { display: grid; grid-template-columns: auto 1fr; gap: 4px 10px; } .contact-list b { grid-column: 2; } .contact-list span { grid-column: 2; color: var(--muted); }
.ok { color: var(--accent); font-weight: 700; }
.faq { display: grid; gap: 10px; } .faq summary { cursor: pointer; font-weight: 700; min-height: 44px; display: flex; align-items: center; } .faq details p { margin: .5em 0 0; color: var(--muted); }

/* Footer, toast */
.site-footer { margin-top: 40px; border-top: 1px solid var(--line); background: var(--alt); padding: 32px 0 20px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 24px; }
.footer-grid h4 { margin: 0 0 8px; } .footer-grid a, .footer-grid span { display: block; color: var(--muted); text-decoration: none; padding: 4px 0; font-size: .95rem; }
.footer-grid a { min-height: 32px; } .demo-note { margin-top: 20px; font-size: .85rem; color: var(--muted); border-top: 1px solid var(--line); padding-top: 14px; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 30px); background: var(--ink); color: var(--bg); padding: 12px 20px; border-radius: 999px; font-weight: 600; opacity: 0; pointer-events: none; transition: .25s; z-index: 100; max-width: 90vw; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* Mobile */
@media (max-width: 860px) {
  .hamburger { display: inline-flex; }
  .nav { display: none; position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; background: var(--bg); border-bottom: 1px solid var(--line); padding: 8px 16px 16px; }
  .nav.open { display: flex; }
  .hero-grid, .pack-teaser, .detail, .contact-grid, .cart-grid, .compare { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }
  .steps { grid-template-columns: repeat(2, 1fr); } .steps li::after { display: none; }
  .footer-grid { grid-template-columns: 1fr; }
  .summary { position: static; }
  .section { padding: 28px 0; }
}
@media (max-width: 420px) {
  .brand-text { font-size: 1rem; } .cart-row { flex-direction: column; align-items: stretch; } .line-total { text-align: left; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }

/* Sửa sau khi test mobile */
.form label.check { display: flex; font-weight: 500; font-size: 1rem; }
.card-body h3 a { display: block; padding: 12px 0; margin: -12px 0; }
.footer-grid a { min-height: 44px; display: flex; align-items: center; }
.section-head a, .muted[href] { display: inline-flex; align-items: center; min-height: 44px; }
.brand { min-height: 44px; }
@media (max-width: 420px) {
  .cart-row { flex-direction: row; align-items: center; }
  .cart-row .grow { flex-basis: 100%; }
  .line-total { text-align: right; margin-left: auto; }
}
.check input { flex: none; }
#quiz-go { margin-top: 10px; } #quiz-out { margin-top: 12px; }