/* ==========================================================================
   Luztrend — Design System
   Product: AI hardware box with on-device agent + cloud-model intelligence
   ========================================================================== */

:root {
  /* Palette */
  --bg: #ffffff;
  --bg-soft: #f5f6fa;
  --ink: #0d1220;
  --ink-soft: #3c4557;
  --muted: #69718a;
  --line: #e6e8f0;
  --line-strong: #d5d8e5;

  --brand: #4f46e5;
  --brand-2: #7c3aed;
  --accent: #06b6d4;

  --dark: #0b1020;
  --dark-2: #111839;
  --dark-ink: #e8ecf8;
  --dark-muted: #9aa4c4;

  --gradient: linear-gradient(120deg, #4f46e5 0%, #7c3aed 52%, #06b6d4 120%);
  --gradient-soft: linear-gradient(120deg, #eef0ff 0%, #f3eefe 50%, #e6f9fd 100%);

  --success: #10b981;
  --warn: #f59e0b;

  /* Type */
  --font-sans: "Inter", "SF Pro Display", -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC",
    "Microsoft YaHei", sans-serif;
  --font-display: "Space Grotesk", var(--font-sans);

  /* Metrics */
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --shadow-sm: 0 1px 2px rgba(13, 18, 32, 0.06);
  --shadow: 0 8px 30px rgba(13, 18, 32, 0.08);
  --shadow-lg: 0 24px 60px rgba(13, 18, 32, 0.14);
  --shadow-glow: 0 0 0 1px rgba(79, 70, 229, 0.12),
    0 18px 50px rgba(79, 70, 229, 0.25);

  --container: 1180px;
  --header-h: 100px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.15; margin: 0; letter-spacing: -0.02em; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
ul { margin: 0; padding: 0; list-style: none; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: 96px 0; }
.section--soft { background: var(--bg-soft); }
.section--dark { background: var(--dark); color: var(--dark-ink); }

/* ---------- Utility ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--brand);
}
.eyebrow::before {
  content: ""; width: 22px; height: 2px; border-radius: 2px;
  background: var(--gradient);
}
.section-head { max-width: 720px; margin: 0 auto 56px; text-align: center; }
.section-head h2 { font-size: clamp(28px, 4vw, 42px); margin: 14px 0 16px; }
.section-head p { color: var(--muted); font-size: 18px; }
.section--dark .section-head p { color: var(--dark-muted); }

.grad-text {
  background: var(--gradient);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 24px; border-radius: 999px; font-weight: 600; font-size: 15px;
  cursor: pointer; border: 1px solid transparent; transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn--primary { background: var(--gradient); color: #fff; box-shadow: var(--shadow-glow); }
.btn--primary:hover { transform: translateY(-2px); }
.btn--ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn--ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn--on-dark { background: #fff; color: var(--dark); }
.btn--on-dark:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(255,255,255,.15); }
.btn--lg { padding: 16px 32px; font-size: 16px; }
.btn--block { width: 100%; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  height: var(--header-h);
  background: rgba(255,255,255,0.82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav {
  height: var(--header-h); display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 700; font-size: 19px; letter-spacing: -0.02em; }
.brand .logo {
  width: 34px; height: 34px; border-radius: 10px; background: var(--gradient);
  display: grid; place-items: center; color: #fff; font-size: 16px; box-shadow: var(--shadow-glow);
}
.logo-img { height: 64px; width: auto; display: block; }
.site-footer .brand .logo-img { display: none; }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a { padding: 8px 14px; border-radius: 999px; font-size: 14.5px; font-weight: 500; color: var(--ink-soft); transition: background .15s, color .15s; }
.nav-links a:hover, .nav-links a.active { background: var(--bg-soft); color: var(--ink); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.cart-badge {
  position: relative; width: 40px; height: 40px; border-radius: 50%;
  display: grid; place-items: center; border: 1px solid var(--line-strong); background: #fff; cursor: pointer;
}
.cart-badge .count {
  position: absolute; top: -4px; right: -4px; min-width: 18px; height: 18px; padding: 0 4px;
  border-radius: 9px; background: var(--gradient); color: #fff; font-size: 11px; font-weight: 700;
  display: grid; place-items: center;
}
.nav-toggle { display: none; width: 40px; height: 40px; border-radius: 10px; border: 1px solid var(--line-strong); background: #fff; cursor: pointer; font-size: 18px; }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background:
    radial-gradient(1100px 500px at 78% -10%, rgba(124, 58, 237, 0.16), transparent 60%),
    radial-gradient(900px 500px at 8% 110%, rgba(6, 182, 212, 0.14), transparent 60%),
    var(--bg);
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 48px; align-items: center; padding: 72px 0 88px; }
.hero h1 { font-size: clamp(34px, 5vw, 58px); margin: 18px 0 22px; }
.hero .lead { font-size: 19px; color: var(--muted); max-width: 540px; }
.hero-cta { display: flex; gap: 14px; margin: 30px 0 22px; flex-wrap: wrap; }
.hero-proof { display: flex; gap: 22px; flex-wrap: wrap; color: var(--muted); font-size: 14px; }
.hero-proof span { display: flex; align-items: center; gap: 7px; }
.hero-proof b { color: var(--ink); }

/* Device illustration */
.hero-visual { position: relative; display: grid; place-items: center; }
.device {
  width: min(420px, 90%); aspect-ratio: 1; border-radius: 34px;
  background: var(--gradient-soft);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-lg);
  display: grid; place-items: center; position: relative;
}
.orbit { position: absolute; inset: 0; border-radius: 34px; }
.orbit::before, .orbit::after {
  content: ""; position: absolute; border-radius: 50%;
  border: 1.5px dashed rgba(79, 70, 229, 0.35);
  animation: spin 30s linear infinite;
}
.orbit::before { inset: -26px; }
.orbit::after { inset: 12px; border-color: rgba(6, 182, 212, 0.35); animation-duration: 22s; animation-direction: reverse; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Cards ---------- */
.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--line-strong); }
.card .icon {
  width: 48px; height: 48px; border-radius: 13px; background: var(--gradient-soft);
  display: grid; place-items: center; font-size: 22px; margin-bottom: 18px;
  box-shadow: inset 0 0 0 1px rgba(79,70,229,.08);
}
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

/* ---------- Steps ---------- */
.steps { counter-reset: step; }
.step { position: relative; padding: 30px; }
.step .num {
  width: 42px; height: 42px; border-radius: 12px; background: var(--gradient);
  color: #fff; font-weight: 700; font-size: 18px; display: grid; place-items: center; margin-bottom: 18px;
}

/* ---------- Specs / table ---------- */
.spec-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.spec-row { display: flex; padding: 16px 22px; gap: 16px; }
.spec-row:nth-child(odd) { background: var(--bg-soft); }
.spec-row .k { flex: 0 0 160px; font-weight: 600; color: var(--ink); }
.spec-row .v { color: var(--muted); }

/* ---------- Model logos ---------- */
.model-row { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.model-chip {
  display: inline-flex; align-items: center; gap: 9px; padding: 11px 18px;
  border: 1px solid var(--line-strong); border-radius: 999px; background: #fff;
  font-weight: 600; font-size: 14px; color: var(--ink-soft);
}
.model-chip .dot { width: 9px; height: 9px; border-radius: 50%; }

/* ---------- Use cases / tabs ---------- */
.tabs { display: flex; gap: 8px; justify-content: center; margin-bottom: 40px; background: var(--bg-soft); padding: 6px; border-radius: 999px; width: fit-content; margin-inline: auto; }
.tab { padding: 10px 22px; border-radius: 999px; font-weight: 600; font-size: 14.5px; cursor: pointer; border: none; background: transparent; color: var(--muted); transition: all .15s; }
.tab.active { background: #fff; color: var(--ink); box-shadow: var(--shadow-sm); }
.tab-panel { display: none; }
.tab-panel.active { display: grid; animation: fade .25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; } }

/* ---------- Pricing ---------- */
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; align-items: stretch; }
.price-card { position: relative; display: flex; flex-direction: column; padding: 34px 30px; }
.price-card.featured { border-color: var(--brand); box-shadow: var(--shadow-glow); transform: translateY(-8px); }
.price-card .tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--gradient); color: #fff; font-size: 12px; font-weight: 700;
  padding: 5px 14px; border-radius: 999px; letter-spacing: .04em;
}
.price-card .name { font-size: 15px; font-weight: 600; color: var(--muted); }
.price-card .amount { font-size: 44px; font-weight: 700; font-family: var(--font-display); margin: 10px 0 4px; }
.price-card .amount small { font-size: 16px; font-weight: 500; color: var(--muted); }
.price-card .desc { color: var(--muted); font-size: 14.5px; margin-bottom: 22px; }
.price-card .features { flex: 1; display: flex; flex-direction: column; gap: 12px; margin-bottom: 26px; }
.price-card .features li { display: flex; gap: 10px; font-size: 14.5px; color: var(--ink-soft); }
.price-card .features li::before { content: "✓"; color: var(--brand); font-weight: 700; }
.price-card .btn { margin-top: auto; }

/* ---------- FAQ ---------- */
.faq { max-width: 780px; margin: 0 auto; }
.faq-item { border: 1px solid var(--line); border-radius: var(--radius); margin-bottom: 14px; overflow: hidden; background: #fff; }
.faq-q { width: 100%; display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 20px 24px; background: none; border: none; cursor: pointer; font-size: 16.5px; font-weight: 600; font-family: var(--font-sans); text-align: left; color: var(--ink); }
.faq-q .plus { font-size: 22px; color: var(--brand); transition: transform .2s; flex: 0 0 auto; }
.faq-item.open .plus { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.faq-a p { padding: 0 24px 22px; color: var(--muted); }

/* ---------- CTA band ---------- */
.cta-band { text-align: center; padding: 90px 0; }
.cta-band h2 { font-size: clamp(28px, 4vw, 44px); margin: 14px 0 18px; }
.cta-band p { color: var(--muted); font-size: 18px; max-width: 560px; margin: 0 auto 30px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--dark); color: var(--dark-muted); padding: 70px 0 30px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 50px; }
.site-footer .brand { color: #fff; margin-bottom: 16px; }
.site-footer h4 { color: #fff; font-size: 13px; text-transform: uppercase; letter-spacing: .1em; margin-bottom: 18px; font-family: var(--font-sans); }
.footer-col a { display: block; padding: 6px 0; color: var(--dark-muted); transition: color .15s; }
.footer-col a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding-top: 26px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px; color: #6b7593; }

/* ---------- Product page ---------- */
.page-hero { background: var(--dark); color: var(--dark-ink); padding: 80px 0; }
.page-hero .section-head { text-align: left; margin: 0; }
.page-hero .section-head p { color: var(--dark-muted); }
.breadcrumb { font-size: 13px; color: var(--dark-muted); margin-bottom: 20px; }
.breadcrumb a:hover { color: #fff; }

/* ---------- Checkout ---------- */
.checkout-grid { display: grid; grid-template-columns: 1.25fr 0.75fr; gap: 40px; align-items: start; }
.panel { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 32px; }
.panel h2 { font-size: 22px; margin-bottom: 24px; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 13.5px; font-weight: 600; margin-bottom: 7px; color: var(--ink-soft); }
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
  font-size: 15px; font-family: inherit; background: #fff; transition: border-color .15s, box-shadow .15s;
}
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px rgba(79,70,229,.12); }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.pay-option {
  display: flex; align-items: center; gap: 14px; padding: 16px 18px; border: 1px solid var(--line-strong);
  border-radius: var(--radius); cursor: pointer; margin-bottom: 12px; transition: border-color .15s, background .15s;
}
.pay-option:hover { border-color: var(--brand); }
.pay-option input { accent-color: var(--brand); width: 18px; height: 18px; }
.pay-option .pay-name { font-weight: 600; font-size: 15px; }
.pay-option .pay-note { font-size: 13px; color: var(--muted); }
.order-summary { position: sticky; top: calc(var(--header-h) + 20px); }
.order-line { display: flex; justify-content: space-between; padding: 10px 0; font-size: 15px; color: var(--ink-soft); }
.order-line.total { border-top: 1px solid var(--line); margin-top: 10px; padding-top: 16px; font-weight: 700; color: var(--ink); font-size: 18px; }
.notice {
  display: flex; gap: 10px; align-items: flex-start; padding: 14px 16px; border-radius: var(--radius-sm);
  background: #fffbeb; border: 1px solid #fde68a; color: #92400e; font-size: 13.5px; margin-bottom: 18px;
}

/* ---------- Toast ---------- */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%) translateY(20px);
  background: var(--dark); color: #fff; padding: 13px 22px; border-radius: 999px; font-size: 14.5px;
  opacity: 0; pointer-events: none; transition: all .3s; z-index: 200; box-shadow: var(--shadow-lg);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; padding: 48px 0 64px; }
  .hero-visual { order: -1; }
  .grid-3, .grid-4, .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .checkout-grid, .footer-grid { grid-template-columns: 1fr; }
  .order-summary { position: static; }
  .nav-links {
    position: fixed; top: var(--header-h); left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 4px; padding: 16px 24px;
    background: #fff; border-bottom: 1px solid var(--line); display: none;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: grid; }
}
@media (max-width: 600px) {
  :root { --header-h: 72px; }
  .logo-img { height: 42px; }
  .section { padding: 64px 0; }
  .grid-3, .grid-4, .grid-2, .pricing-grid, .field-row { grid-template-columns: 1fr; }
  .spec-list { grid-template-columns: 1fr; }
  .spec-row { flex-direction: column; gap: 4px; }
  .spec-row .k { flex: none; }
  .price-card.featured { transform: none; }
  .btn--lg { width: 100%; }
}