/* IAAI official site. Night-sky theme matching the app's default look. */
:root {
  --bg: #0b0d1a;
  --bg-2: #11142a;
  --surface: #161a33;
  --surface-2: #1d2242;
  --line: rgba(255, 255, 255, .09);
  --line-strong: rgba(255, 255, 255, .16);
  --text: #eef0fa;
  --text-2: #b8bdd6;
  --muted: #8a90ad;
  --gold: #f2c46d;
  --gold-soft: rgba(242, 196, 109, .12);
  --violet: #8b7bff;
  --violet-soft: rgba(139, 123, 255, .14);
  --radius: 18px;
  --max: 1120px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  font-size: 16px; line-height: 1.7;
}
a { color: var(--gold); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* Language: every bilingual block carries data-l; the inactive one is hidden. */
html[data-lang="zh"] [data-l="en"], html[data-lang="en"] [data-l="zh"] { display: none !important; }

.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 13, 26, .78); backdrop-filter: saturate(160%) blur(14px); -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; gap: 24px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 19px; letter-spacing: .5px; }
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.site-nav { display: flex; gap: 22px; margin-left: auto; }
.site-nav a { color: var(--text-2); font-size: 14px; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--text); text-decoration: none; }
.header-actions { display: flex; align-items: center; gap: 10px; }
.lang-toggle {
  background: none; border: 1px solid var(--line-strong); color: var(--text-2); border-radius: 999px;
  padding: 5px 12px; font: inherit; font-size: 13px; cursor: pointer;
}
.lang-toggle:hover { color: var(--text); border-color: var(--text-2); }
.menu-toggle { display: none; background: none; border: 0; color: var(--text); font-size: 22px; cursor: pointer; padding: 4px 6px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 22px; border-radius: 999px; font-weight: 600; font-size: 15px; border: 1px solid transparent;
  transition: transform .15s, background .15s, border-color .15s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--gold); color: #1b1608; }
.btn-primary:hover { background: #f6d18c; }
.btn-ghost { border-color: var(--line-strong); color: var(--text); }
.btn-ghost:hover { border-color: var(--text-2); }
.btn-sm { padding: 7px 16px; font-size: 14px; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 96px 0 88px; text-align: center; }
.hero::before {
  content: ''; position: absolute; inset: -40% -10% auto; height: 640px; pointer-events: none;
  background: radial-gradient(closest-side, rgba(139, 123, 255, .28), transparent 70%),
              radial-gradient(closest-side at 70% 60%, rgba(242, 196, 109, .14), transparent 70%);
}
.hero .stars { position: absolute; inset: 0; pointer-events: none; opacity: .55;
  background-image:
    radial-gradient(1px 1px at 12% 22%, #fff 50%, transparent 51%), radial-gradient(1px 1px at 28% 68%, #fff 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 44% 14%, #fff 50%, transparent 51%), radial-gradient(1px 1px at 63% 42%, #fff 50%, transparent 51%),
    radial-gradient(1px 1px at 78% 18%, #fff 50%, transparent 51%), radial-gradient(1.5px 1.5px at 88% 64%, #fff 50%, transparent 51%),
    radial-gradient(1px 1px at 8% 82%, #fff 50%, transparent 51%), radial-gradient(1px 1px at 52% 86%, #fff 50%, transparent 51%);
}
.hero .wrap { position: relative; }
.eyebrow { display: inline-block; color: var(--gold); background: var(--gold-soft); border: 1px solid rgba(242, 196, 109, .25);
  border-radius: 999px; padding: 4px 14px; font-size: 13px; letter-spacing: .5px; margin-bottom: 22px; }
.hero h1 { font-size: clamp(34px, 6vw, 60px); line-height: 1.15; margin: 0 0 20px; letter-spacing: -.5px; }
.hero h1 em { font-style: normal; background: linear-gradient(100deg, var(--gold), #ffe3a8 40%, var(--violet)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { color: var(--text-2); font-size: clamp(16px, 2.2vw, 19px); max-width: 680px; margin: 0 auto 34px; }
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-note { margin-top: 18px; color: var(--muted); font-size: 13px; }

/* Sections */
section.block { padding: 84px 0; border-top: 1px solid var(--line); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 48px; }
.section-head h2 { font-size: clamp(26px, 3.6vw, 36px); margin: 0 0 12px; line-height: 1.25; }
.section-head p { color: var(--text-2); margin: 0; }

.grid { display: grid; gap: 18px; }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.card h3 { margin: 14px 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--text-2); font-size: 15px; }
.icon { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: var(--violet-soft); color: var(--violet); }
.icon svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.icon.gold { background: var(--gold-soft); color: var(--gold); }

.steps { counter-reset: step; }
.steps .card { position: relative; padding-top: 30px; }
.steps .card::before { counter-increment: step; content: counter(step); position: absolute; top: -14px; left: 24px;
  width: 30px; height: 30px; border-radius: 50%; background: var(--gold); color: #1b1608; font-weight: 700; display: grid; place-items: center; font-size: 14px; }

/* Pricing */
.price-split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 18px; margin-bottom: 18px; }
.price-card h3 { margin-top: 0; }
.price-card ul { margin: 12px 0 0; padding-left: 20px; color: var(--text-2); font-size: 15px; }
.price-card li { margin: 4px 0; }
.big { font-size: 30px; font-weight: 700; color: var(--text); line-height: 1.2; }
.big small { font-size: 15px; color: var(--muted); font-weight: 500; }
.methods { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.methods span { border: 1px solid var(--line-strong); border-radius: 8px; padding: 3px 10px; font-size: 13px; color: var(--text-2); }
.plans { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.plan { display: flex; flex-direction: column; }
.plan .plan-name { font-weight: 700; font-size: 17px; }
.plan .plan-price { margin: 10px 0 2px; }
.plan .plan-day { color: var(--muted); font-size: 13px; }
.plan ul { list-style: none; padding: 0; margin: 16px 0 0; font-size: 14px; color: var(--text-2); }
.plan li { padding: 5px 0; border-top: 1px solid var(--line); display: flex; gap: 8px; }
.plan li.off { color: var(--muted); text-decoration: line-through; }
.plan li::before { content: '✓'; color: var(--gold); flex: none; }
.plan li.off::before { content: '–'; color: var(--muted); }
.plan.free { background: var(--bg-2); }
.plan-note, .fine { color: var(--muted); font-size: 13px; margin-top: 16px; }
.loading { color: var(--muted); font-size: 14px; }

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; }
.faq details { border-bottom: 1px solid var(--line); padding: 18px 4px; }
.faq summary { cursor: pointer; font-weight: 600; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; color: var(--gold); font-size: 20px; line-height: 1; }
.faq details[open] summary::after { content: '–'; }
.faq details p { color: var(--text-2); margin: 12px 0 0; }

.cta { text-align: center; }
.cta .card { padding: 48px 24px; background: linear-gradient(135deg, rgba(139, 123, 255, .18), rgba(242, 196, 109, .1)); border-color: var(--line-strong); }
.cta h2 { margin: 0 0 10px; font-size: clamp(24px, 3.4vw, 32px); }
.cta p { color: var(--text-2); margin: 0 0 26px; }

/* Legal pages */
.doc { padding: 64px 0 88px; }
.doc .wrap { max-width: 820px; }
.doc h1 { font-size: clamp(28px, 4vw, 38px); margin: 0 0 6px; }
.doc .updated { color: var(--muted); font-size: 14px; margin: 0 0 36px; }
.doc h2 { font-size: 20px; margin: 40px 0 12px; padding-top: 8px; }
.doc h3 { font-size: 16px; margin: 24px 0 8px; }
.doc p, .doc li { color: var(--text-2); }
.doc ul, .doc ol { padding-left: 22px; }
.doc li { margin: 6px 0; }
.doc strong { color: var(--text); }
.doc .summary { background: var(--surface); border: 1px solid var(--line); border-left: 3px solid var(--gold); border-radius: 12px; padding: 16px 20px; margin: 0 0 8px; }
.doc .summary p { margin: 0; }
.info-table { width: 100%; border-collapse: collapse; margin: 8px 0; }
.info-table th, .info-table td { text-align: left; vertical-align: top; padding: 12px 0; border-bottom: 1px solid var(--line); }
.info-table th { width: 34%; color: var(--muted); font-weight: 500; padding-right: 16px; }
.info-table td { color: var(--text); word-break: break-word; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); background: var(--bg-2); padding: 48px 0 36px; color: var(--muted); font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; }
.footer-grid h4 { color: var(--text); font-size: 14px; margin: 0 0 12px; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin: 6px 0; }
.footer-grid a { color: var(--text-2); }
.footer-company { line-height: 1.8; }
.footer-bottom { margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }

@media (max-width: 900px) {
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid > :first-child { grid-column: 1 / -1; }
}
@media (max-width: 720px) {
  .wrap { padding: 0 16px; }
  .menu-toggle { display: block; }
  .site-nav { display: none; position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: var(--bg-2); border-bottom: 1px solid var(--line); padding: 8px 16px; }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 12px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
  .site-nav a:last-child { border-bottom: 0; }
  .header-actions { margin-left: auto; }
  .header-actions .btn { display: none; }
  .grid-3, .grid-2, .price-split { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 60px; }
  section.block { padding: 60px 0; }
  .info-table th { width: 38%; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .btn { transition: none; } }