/* LUXCAR landing page — HTML/CSS/JS thuần, không framework */

:root {
  --bg: #0b0b0f;
  --bg-2: #121218;
  --bg-3: #1a1a22;
  --line: rgba(255, 255, 255, .08);
  --line-2: rgba(255, 255, 255, .14);
  --text: #f4f4f6;
  --muted: #a3a3ad;
  --red: #e63529;
  --orange: #ec5e2c;
  --deep: #8a1e16;
  --grad: linear-gradient(135deg, #ff6a3d 0%, #e63529 55%, #b52a1d 100%);
  --radius: 18px;
  --radius-lg: 28px;
  --shadow: 0 30px 80px -30px rgba(0, 0, 0, .8);
  --container: 1180px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { line-height: 1.15; margin: 0 0 .5em; letter-spacing: -.02em; }
h2 { font-size: clamp(28px, 4vw, 44px); }
h3 { font-size: 19px; letter-spacing: -.01em; }
p { margin: 0 0 1em; }
button { font: inherit; color: inherit; cursor: pointer; }
:focus-visible { outline: 2px solid var(--orange); outline-offset: 3px; border-radius: 6px; }

.sprite { position: absolute; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  background: var(--red); color: #fff; padding: 10px 16px; border-radius: 10px;
}
.skip-link:focus { top: 12px; }

.container { width: min(100% - 40px, var(--container)); margin-inline: auto; }
.container.narrow { max-width: 820px; }
.ic { width: 20px; height: 20px; fill: currentColor; flex: none; }
.grad {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}

/* Nút */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 12px 20px; border-radius: 999px; font-weight: 600;
  border: 1px solid transparent; transition: transform .2s, box-shadow .2s, background .2s;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn-lg { padding: 16px 28px; font-size: 17px; }
.btn-sm { padding: 8px 16px; font-size: 15px; }
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 12px 30px -10px rgba(230, 53, 41, .7); }
.btn-primary:hover { box-shadow: 0 18px 40px -12px rgba(230, 53, 41, .9); }
.btn-ghost { border-color: var(--line-2); background: rgba(255, 255, 255, .04); }
.btn-ghost:hover { background: rgba(255, 255, 255, .09); }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase;
  color: var(--orange); margin-bottom: 14px;
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 4px rgba(236, 94, 44, .2); }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 11, 15, .72);
  -webkit-backdrop-filter: saturate(160%) blur(14px); backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .08em; }
.brand img { border-radius: 9px; }
.nav-menu { display: flex; align-items: center; gap: 26px; font-size: 15px; color: var(--muted); }
.nav-menu a:not(.btn):hover { color: var(--text); }
.nav-menu .btn { color: #fff; }
.nav-toggle {
  display: none; width: 44px; height: 44px; border: 1px solid var(--line-2); border-radius: 12px;
  background: transparent; position: relative;
}
.nav-toggle span { position: absolute; left: 12px; right: 12px; height: 2px; background: var(--text); transition: transform .25s; }
.nav-toggle span:first-child { top: 16px; }
.nav-toggle span:last-child { bottom: 16px; }
.nav-toggle[aria-expanded="true"] span:first-child { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child { transform: translateY(-4px) rotate(-45deg); }

/* Hero */
.hero { position: relative; padding: 72px 0 40px; overflow: hidden; }
.hero-glow {
  position: absolute; inset: -20% -10% auto; height: 760px; pointer-events: none;
  background:
    radial-gradient(600px 380px at 78% 30%, rgba(230, 53, 41, .28), transparent 70%),
    radial-gradient(500px 340px at 10% 10%, rgba(236, 94, 44, .14), transparent 70%);
}
.hero-grid { position: relative; display: grid; grid-template-columns: 1fr 1.25fr; gap: 56px; align-items: center; }
.hero h1 { font-size: clamp(36px, 5.2vw, 62px); font-weight: 800; }
.lead { font-size: 19px; color: var(--muted); max-width: 560px; }
.lead strong { color: var(--text); }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin: 28px 0 22px; }
.hero-points { list-style: none; display: flex; flex-wrap: wrap; gap: 10px 22px; padding: 0; margin: 0; font-size: 15px; color: var(--muted); }
.hero-points li { display: flex; align-items: center; gap: 6px; }
.hero-points .ic { width: 18px; height: 18px; color: #4ade80; }

.keyword-strip {
  position: relative; display: flex; flex-wrap: wrap; justify-content: center; gap: 10px;
  margin-top: 64px; padding-top: 28px; border-top: 1px solid var(--line);
}
.keyword-strip span {
  padding: 8px 16px; border-radius: 999px; font-size: 14px; color: var(--muted);
  border: 1px solid var(--line); background: rgba(255, 255, 255, .02);
}

/* ===== Khung màn hình xe chứa ảnh chụp thật ===== */
.hero-device, .theme-view { margin: 0; perspective: 1600px; }
.unit {
  padding: 12px; border-radius: 28px;
  background: linear-gradient(160deg, #2a2a30, #0d0d10 60%);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, .08);
}
.hero-device .unit { transform: rotateY(-8deg) rotateX(4deg); transition: transform .6s; }
.hero-device:hover .unit { transform: none; }
.shot { width: 100%; height: auto; aspect-ratio: 16 / 9; border-radius: 16px; background: #111114; }

/* Sections */
.section { padding: 110px 0; position: relative; }
.section-alt { background: linear-gradient(180deg, var(--bg-2), var(--bg)); border-block: 1px solid var(--line); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head p:not(.eyebrow) { color: var(--muted); font-size: 18px; }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature {
  padding: 28px; border-radius: var(--radius); background: var(--bg-2); border: 1px solid var(--line);
  transition: border-color .25s, transform .25s;
}
.feature:hover { border-color: rgba(236, 94, 44, .45); transform: translateY(-4px); }
.feature p { color: var(--muted); font-size: 16px; margin: 0; }
.f-ic {
  display: grid; place-items: center; width: 48px; height: 48px; border-radius: 14px; margin-bottom: 18px;
  background: linear-gradient(135deg, rgba(255, 106, 61, .18), rgba(230, 53, 41, .08));
  border: 1px solid rgba(236, 94, 44, .3); color: var(--orange);
}
.f-ic svg { width: 24px; height: 24px; fill: currentColor; }

.checks { list-style: none; padding: 0; margin: 22px 0 0; display: grid; gap: 12px; }
.checks li { display: flex; gap: 10px; align-items: flex-start; color: var(--muted); }
.checks .ic { color: var(--orange); margin-top: 3px; }

/* Ảnh chụp thực tế */
.shot-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.shot-item { margin: 0; }
.shot-item a {
  display: block; border-radius: 16px; overflow: hidden; border: 1px solid var(--line);
  background: #111114; box-shadow: 0 18px 40px -22px rgba(0, 0, 0, .9);
  transition: transform .25s, border-color .25s;
}
.shot-item a:hover { transform: translateY(-4px); border-color: rgba(236, 94, 44, .5); }
.shot-item img { width: 100%; height: auto; aspect-ratio: 16 / 9; }
.shot-item figcaption { display: flex; flex-direction: column; gap: 2px; padding: 12px 4px 0; }
.shot-item figcaption span { color: var(--muted); font-size: 15px; }

.lightbox {
  width: min(96vw, 1600px); max-width: none; max-height: 96vh; padding: 0; border: 0; border-radius: 18px;
  background: #0b0b0f; color: var(--text); overflow: visible;
}
.lightbox::backdrop { background: rgba(0, 0, 0, .82); backdrop-filter: blur(4px); }
.lightbox img { width: 100%; height: auto; max-height: calc(96vh - 52px); object-fit: contain; border-radius: 18px 18px 0 0; }
.lb-cap { margin: 0; padding: 14px 18px; font-size: 15px; color: var(--muted); }
.lb-close {
  position: absolute; top: -14px; right: -14px; width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid var(--line-2); background: #1d1d24; font-size: 24px; line-height: 1;
}

/* Chia màn hình */
.split-grid, .assist-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: 64px; align-items: center; }
.split-grid > div > p, .assist-grid > div > p { color: var(--muted); font-size: 18px; }
.layout-tabs { display: inline-flex; padding: 5px; gap: 4px; border-radius: 999px; background: var(--bg-3); border: 1px solid var(--line); margin-top: 8px; }
.layout-tabs button { border: 0; background: transparent; padding: 9px 18px; border-radius: 999px; font-size: 15px; color: var(--muted); }
.layout-tabs button[aria-selected="true"] { background: var(--grad); color: #fff; }

.layout-demo {
  display: grid; gap: 12px; padding: 14px; border-radius: var(--radius-lg); aspect-ratio: 16 / 9;
  background: #0d0d11; border: 1px solid var(--line); box-shadow: var(--shadow);
  grid-template-columns: 1fr 2fr 0fr; transition: grid-template-columns .5s cubic-bezier(.2, .8, .2, 1);
}
.layout-demo[data-layout="narrow"] { grid-template-columns: 2fr 1fr 0fr; }
.layout-demo[data-layout="three"] { grid-template-columns: 1fr 1fr 1fr; }
.ld-pane {
  min-width: 0; overflow: hidden; border-radius: 16px; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 10px; font-weight: 600; font-size: 15px;
  transition: opacity .4s;
}
.ld-pane svg { width: 40px; height: 40px; fill: currentColor; }
.ld-dash { background: linear-gradient(160deg, #1d1d24, #141419); border: 1px solid var(--line); align-items: stretch; padding: 16px; justify-content: flex-start; }
.ld-dash span { color: var(--muted); font-size: 13px; }
.ld-dash i { display: block; border-radius: 12px; background: rgba(255, 255, 255, .06); flex: 1; }
.ld-app1 { background: linear-gradient(160deg, #10351f, #0b2015); color: #4ade80; }
.ld-app2 { background: linear-gradient(160deg, #3a1110, #200a09); color: #ff6a5c; }
.layout-demo:not([data-layout="three"]) .ld-app2 { opacity: 0; }

.split-visual { position: relative; padding-bottom: 56px; }
.lp-inset {
  position: absolute; right: -12px; bottom: 0; width: 42%; margin: 0;
  border-radius: 16px; overflow: hidden; border: 1px solid var(--line-2);
  box-shadow: 0 24px 50px -16px rgba(0, 0, 0, .9);
}
.lp-inset img { width: 100%; height: auto; }
.lp-inset figcaption {
  position: absolute; left: 10px; bottom: 10px; padding: 4px 10px; border-radius: 999px;
  background: rgba(11, 11, 15, .8); font-size: 13px; font-weight: 600;
}

/* Trợ lý */
.assist-demo {
  position: relative; display: flex; flex-direction: column; gap: 12px; padding: 28px 28px 110px;
  border-radius: var(--radius-lg); background: var(--bg-2); border: 1px solid var(--line); box-shadow: var(--shadow);
}
.bubble { max-width: 78%; padding: 12px 16px; border-radius: 18px; font-size: 16px; display: flex; gap: 8px; align-items: center; }
.bubble svg { width: 18px; height: 18px; fill: currentColor; flex: none; }
.bubble.user { align-self: flex-end; background: var(--grad); color: #fff; border-bottom-right-radius: 6px; }
.bubble.bot { align-self: flex-start; background: var(--bg-3); border: 1px solid var(--line); border-bottom-left-radius: 6px; }
.mic-orb {
  position: absolute; left: 50%; bottom: 24px; transform: translateX(-50%);
  width: 64px; height: 64px; border-radius: 50%; display: grid; place-items: center;
  background: var(--grad); color: #fff; box-shadow: 0 10px 30px -8px rgba(230, 53, 41, .8);
}
.mic-orb svg { width: 28px; height: 28px; fill: currentColor; position: relative; z-index: 1; }
.mic-orb span { position: absolute; inset: 0; border-radius: 50%; border: 2px solid rgba(236, 94, 44, .6); animation: ring 2.4s ease-out infinite; }
.mic-orb span + span { animation-delay: 1.2s; }
@keyframes ring { from { transform: scale(1); opacity: 1; } to { transform: scale(1.9); opacity: 0; } }

/* Giao diện */
.theme-view { max-width: 964px; margin: 0 auto 32px; }
.theme-view .shot { transition: opacity .25s; }
.theme-view .shot.loading { opacity: .55; }
.theme-picker { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }
.theme-picker button {
  display: inline-flex; align-items: center; gap: 10px; padding: 8px 18px 8px 8px; border-radius: 999px;
  background: var(--bg-3); border: 1px solid var(--line); font-size: 15px; transition: border-color .2s, background .2s;
}
.theme-picker button span { width: 28px; height: 28px; border-radius: 50%; background: linear-gradient(135deg, var(--sw2), var(--sw)); border: 1px solid var(--line-2); }
.theme-picker button:hover { border-color: var(--line-2); }
.theme-picker button[aria-checked="true"] { border-color: var(--orange); background: rgba(236, 94, 44, .12); }
.theme-extra { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-top: 44px; }
.theme-extra div { padding: 20px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--bg-2); display: flex; flex-direction: column; gap: 4px; }
.theme-extra span { color: var(--muted); font-size: 15px; }

/* Cài đặt */
.steps { list-style: none; padding: 0; margin: 0 0 56px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: s; }
.steps li { padding: 28px; border-radius: var(--radius); background: var(--bg-2); border: 1px solid var(--line); }
.steps p { color: var(--muted); margin: 0; font-size: 16px; }
.num {
  display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; margin-bottom: 16px;
  background: var(--grad); font-weight: 800; color: #fff;
}
.editions { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; max-width: 920px; margin: 0 auto; }
.edition { position: relative; padding: 32px; border-radius: var(--radius-lg); background: var(--bg-2); border: 1px solid var(--line); }
.edition.featured { border-color: rgba(236, 94, 44, .5); background: linear-gradient(160deg, rgba(230, 53, 41, .12), var(--bg-2) 60%); }
.edition h3 { font-size: 24px; margin-bottom: 4px; }
.ed-sub { color: var(--muted); margin: 0; }
.badge {
  position: absolute; top: -13px; right: 24px; padding: 4px 12px; border-radius: 999px;
  background: var(--grad); color: #fff; font-size: 12px; font-weight: 700;
}

/* Hỏi đáp */
.faq { display: grid; gap: 12px; }
.faq details { border-radius: var(--radius); background: var(--bg-2); border: 1px solid var(--line); transition: border-color .2s; }
.faq details[open] { border-color: rgba(236, 94, 44, .4); }
.faq summary {
  list-style: none; cursor: pointer; padding: 20px 24px; font-weight: 600; font-size: 17px;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary svg { width: 22px; height: 22px; fill: var(--muted); flex: none; transition: transform .25s; }
.faq details[open] summary svg { transform: rotate(180deg); }
.faq details p { padding: 0 24px 20px; margin: 0; color: var(--muted); }

/* CTA */
.cta { padding-top: 90px; }
.cta-box {
  text-align: center; padding: 64px 32px; border-radius: 36px; position: relative; overflow: hidden;
  background:
    radial-gradient(600px 300px at 50% 0%, rgba(230, 53, 41, .35), transparent 70%),
    linear-gradient(180deg, var(--bg-3), var(--bg-2));
  border: 1px solid rgba(236, 94, 44, .3);
}
.cta-box img { margin: 0 auto 22px; border-radius: 22px; box-shadow: 0 20px 50px -15px rgba(230, 53, 41, .7); }
.cta-box > p { color: var(--muted); }
.cta-box b { color: var(--text); }
.cta-buttons { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; margin-top: 28px; }
.cta-note { margin: 22px auto 0; max-width: 620px; font-size: 14px; }
.cta-note:empty { display: none; }

/* Footer */
.site-footer { padding: 56px 0 28px; border-top: 1px solid var(--line); }
.footer-grid { display: flex; justify-content: space-between; gap: 32px; flex-wrap: wrap; }
.footer-grid p { color: var(--muted); max-width: 360px; margin-top: 12px; font-size: 15px; }
.footer-grid nav { display: flex; flex-wrap: wrap; gap: 12px 26px; color: var(--muted); font-size: 15px; align-content: flex-start; }
.footer-grid nav a:hover { color: var(--text); }
.copyright { margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--line); color: #6b6b75; font-size: 13px; }

/* Hiện dần khi cuộn (chỉ khi JS chạy) */
.js .reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s ease; }
.js .reveal.in { opacity: 1; transform: none; }

/* Responsive */
@media (max-width: 1080px) {
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }
  .hero-copy { text-align: center; }
  .lead { margin-inline: auto; }
  .hero-cta, .hero-points { justify-content: center; }
  .unit { transform: none; }
  .feature-grid, .shot-grid { grid-template-columns: repeat(2, 1fr); }
  .theme-extra { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .nav-toggle { display: block; }
  .nav-menu {
    position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 0;
    padding: 12px 20px 20px; background: rgba(11, 11, 15, .97); border-bottom: 1px solid var(--line);
    display: none;
  }
  .nav-menu.open { display: flex; }
  .nav-menu a:not(.btn) { padding: 14px 4px; border-bottom: 1px solid var(--line); font-size: 17px; }
  .nav-menu .btn { margin-top: 16px; }
  .split-grid, .assist-grid { grid-template-columns: 1fr; gap: 40px; }
  .assist-grid .assist-demo { order: 2; }
  .steps { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .section { padding: 76px 0; }
  .hero { padding-top: 44px; }
  .unit { padding: 7px; border-radius: 18px; }
  .shot { border-radius: 12px; }
  .feature-grid, .theme-extra, .editions { grid-template-columns: 1fr; }
  /* Ảnh thực tế: dải vuốt ngang thay vì 8 ảnh xếp dọc */
  .shot-grid {
    grid-template-columns: none; grid-auto-flow: column; grid-auto-columns: 84%; gap: 14px;
    overflow-x: auto; scroll-snap-type: x mandatory; scrollbar-width: none;
    margin-inline: -20px; padding: 0 20px 8px; scroll-padding-inline: 20px;
  }
  .shot-grid::-webkit-scrollbar { display: none; }
  .shot-item { scroll-snap-align: start; }
  .js .shot-grid .reveal { opacity: 1; transform: none; }
  .lp-inset { right: 0; width: 56%; }
  .theme-picker { gap: 8px; }
  .theme-picker button { padding: 6px 14px 6px 6px; font-size: 14px; gap: 8px; }
  .btn-lg { width: 100%; }
  .layout-tabs { display: flex; }
  .layout-tabs button { flex: 1; padding: 9px 8px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .js .reveal { opacity: 1; transform: none; }
}