/* ============================================================
   Ai8 Studio 官网  —— 静态样式（参照 aionui.com 设计体系）
   主色：橙色 #ff7028  |  字体：系统 sans-serif
   ============================================================ */

:root {
  --primary: #ff7028;
  --primary-hover: #f65f14;
  --primary-soft: #fff0e6;
  --primary-deep: #ff5a13;
  --bg: #ffffff;
  --bg-alt: #faf9f7;
  --ink: #1c1c1e;
  --ink-soft: #5c5c66;
  --muted: #8a8a93;
  --line: #ececef;
  --card: #ffffff;
  --radius: 14px;
  --nav-h: 64px;
  --maxw: 1180px;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 16px 44px rgba(0, 0, 0, 0.12);
}

html[data-dark="true"] {
  --bg: #0f1013;
  --bg-alt: #141519;
  --card: #1a1b20;
  --ink: #f4f4f5;
  --ink-soft: #b7b7c0;
  --muted: #7f7f88;
  --line: #292a31;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 16px 44px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }

body {
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color .3s, color .3s;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  height: 44px; padding: 0 22px; border-radius: 999px;
  font-size: 15px; font-weight: 600; border: 1px solid transparent;
  transition: transform .15s, background-color .2s, box-shadow .2s, color .2s;
  white-space: nowrap;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 8px 20px rgba(255,112,40,.3); }
.btn-primary:hover { background: var(--primary-hover); transform: translateY(-2px); box-shadow: 0 12px 24px rgba(255,112,40,.38); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
.btn lg { height: 52px; padding: 0 30px; font-size: 16px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 100; height: var(--nav-h);
  background: rgba(255,255,255,0.82); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
html[data-dark="true"] .nav { background: rgba(15,16,19,0.82); }
.nav-inner { display: flex; align-items: center; gap: 18px; height: 100%; }
.nav-brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; letter-spacing: -.02em; }
.nav-logo { width: 28px; height: 28px; border-radius: 8px; background: linear-gradient(135deg,#ff7028,#ff9d3c); display: grid; place-items: center; color:#fff; font-weight: 900; }
.nav-links { display: flex; align-items: center; gap: 6px; margin: 0 auto; }
.nav-link { padding: 8px 14px; border-radius: 8px; font-size: 15px; color: var(--ink-soft); font-weight: 500; transition: color .2s, background-color .2s; }
.nav-link:hover { color: var(--ink); background: var(--bg-alt); }
.nav-right { display: flex; align-items: center; gap: 10px; }
.ghost-stars { display: inline-flex; align-items: center; gap: 6px; height: 34px; padding: 0 12px; border: 1px solid var(--line); border-radius: 999px; font-size: 13px; color: var(--ink-soft); }
.ghost-stars .dot { color: var(--primary); }
.lang {
  display: inline-flex; align-items: center; gap: 4px; height: 36px; padding: 0 10px;
  border: 1px solid var(--line); border-radius: 8px; font-size: 14px; color: var(--ink-soft); background: var(--bg);
}
.lang:hover { border-color: var(--primary); color: var(--primary); }

/* ---------- Mobile nav ---------- */
.nav-toggle { display: none; }
@media (max-width: 900px) {
  .nav-links { display: none; position: absolute; top: var(--nav-h); left: 0; right: 0; flex-direction: column; background: var(--bg); border-bottom: 1px solid var(--line); padding: 12px 20px; gap: 4px; }
  .nav-links.open { display: flex; }
  .nav-toggle { display: grid; place-items: center; width: 40px; height: 40px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); }
}

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; padding: 80px 0 60px; }
.hero-blobs { position: absolute; inset: 0; pointer-events: none; }
.hero-blobs::before, .hero-blobs::after { content: ""; position: absolute; border-radius: 50%; filter: blur(70px); opacity: .55; }
.hero-blobs::before { width: 460px; height: 460px; top: -120px; right: -60px; background: radial-gradient(circle,#ffd5b0,#ff702833 60%, transparent); }
.hero-blobs::after { width: 380px; height: 380px; bottom: -140px; left: -80px; background: radial-gradient(circle,#ffb27a,#ff9d3c26 60%, transparent); }
.hero-inner { position: relative; max-width: 860px; text-align: center; margin: 0 auto; }
.hero-badge { display: inline-flex; align-items: center; gap: 7px; height: 30px; padding: 0 13px; border-radius: 999px; background: var(--primary-soft); color: var(--primary); font-size: 13px; font-weight: 600; margin-bottom: 22px; }
.hero h1 { font-size: clamp(32px, 5.2vw, 60px); line-height: 1.08; letter-spacing: -.03em; font-weight: 800; }
.hero h1 .rotate { color: var(--primary); }
.hero-sub { max-width: 640px; margin: 22px auto 0; font-size: 18px; color: var(--ink-soft); }
.hero-cta { display: flex; gap: 14px; justify-content: center; margin-top: 34px; flex-wrap: wrap; }
.hero-note { margin-top: 18px; font-size: 13px; color: var(--muted); }

/* ---------- Section headers ---------- */
.section { padding: 90px 0; border-top: 1px solid var(--line); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 54px; }
.section-kicker { color: var(--primary); font-weight: 700; font-size: 14px; letter-spacing: .04em; text-transform: uppercase; }
.section h2 { font-size: clamp(26px, 3.6vw, 40px); line-height: 1.15; letter-spacing: -.02em; font-weight: 800; margin: 12px 0 16px; }
.section-sub { color: var(--ink-soft); font-size: 17px; }

/* ---------- Canvas / feature ---------- */
.feature { display: grid; grid-template-columns: 1.05fr .95fr; gap: 54px; align-items: center; }
.feature.rev { grid-template-columns: .95fr 1.05fr; }
.feature-media { position: relative; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); background: var(--bg-alt); }
.feature-media img { width: 100%; height: auto; }
.feature-media .winbar { display: flex; gap: 6px; padding: 12px 14px; background: var(--bg-alt); border-bottom: 1px solid var(--line); }
.feature-media .winbar span { width: 10px; height: 10px; border-radius: 50%; }
.feature-media .winbar span:nth-child(1){ background:#ff5f57; } .feature-media .winbar span:nth-child(2){ background:#febc2e; } .feature-media .winbar span:nth-child(3){ background:#28c840; }
.feature-copy h3 { font-size: 28px; font-weight: 800; letter-spacing: -.02em; }
.feature-copy p { margin-top: 14px; color: var(--ink-soft); font-size: 16px; }
.feature-list { list-style: none; margin-top: 22px; display: grid; gap: 12px; }
.feature-list li { display: flex; gap: 10px; align-items: flex-start; color: var(--ink); }
.feature-list li svg { flex: 0 0 20px; color: var(--primary); margin-top: 3px; }

/* ---------- People / profile cards ---------- */
.people { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 16px; }
.person { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); background: var(--card); transition: transform .2s, box-shadow .2s; }
.person:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.person img { aspect-ratio: 3/4; object-fit: cover; }
.person .cap { padding: 10px 12px; font-size: 13px; color: var(--ink-soft); }

/* ---------- Feature steps ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.step { border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 22px; background: var(--card); box-shadow: var(--shadow); transition: transform .2s, box-shadow .2s; }
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.step .num { width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; font-weight: 800; background: var(--primary-soft); color: var(--primary); }
.step h4 { margin: 16px 0 8px; font-size: 18px; }
.step p { color: var(--ink-soft); font-size: 15px; }

/* ---------- Models ---------- */
.models { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; }
.modal-card { border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; background: var(--card); box-shadow: var(--shadow); transition: transform .2s, box-shadow .2s; }
.modal-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.modal-card .type { display: inline-block; height: 24px; padding: 0 10px; border-radius: 999px; font-size: 12px; font-weight: 700; background: var(--primary-soft); color: var(--primary); }
.modal-card h4 { margin: 14px 0 6px; font-size: 17px; }
.modal-card p { color: var(--ink-soft); font-size: 14px; }

/* ---------- FAQ ---------- */
.faq { max-width: 760px; margin: 0 auto; display: grid; gap: 12px; }
.faq-item { border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); }
.faq-q { width: 100%; text-align: left; display: flex; justify-content: space-between; align-items: center; padding: 18px 20px; font-size: 16px; font-weight: 600; color: var(--ink); background: transparent; border: 0; }
.faq-q svg { transition: transform .25s; }
.faq-item.open .faq-q svg { transform: rotate(180deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.faq-item.open .faq-a { max-height: 400px; }
.faq-a-inner { padding: 0 20px 18px; color: var(--ink-soft); font-size: 15px; }

/* ---------- Download CTA ---------- */
.cta { padding: 90px 0; border-top: 1px solid var(--line); }
.cta-box { text-align: center; border-radius: 24px; padding: 60px 30px; background: linear-gradient(135deg, #fff0e6, #fff6ee); border: 1px solid var(--line); }
html[data-dark="true"] .cta-box { background: linear-gradient(135deg,#241812,#1a1b20); }
.cta-box h2 { font-size: clamp(28px, 4vw, 44px); font-weight: 800; letter-spacing: -.02em; }
.cta-box p { margin: 16px auto 0; max-width: 560px; color: var(--ink-soft); font-size: 17px; }
.cta-box .btn { margin-top: 28px; }
.cta-meta { margin-top: 18px; font-size: 13px; color: var(--muted); }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 56px 0 34px; background: var(--bg-alt); }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px; }
.footer h5 { font-size: 14px; font-weight: 700; margin-bottom: 14px; }
.footer li { list-style: none; margin-bottom: 10px; }
.footer li a { color: var(--ink-soft); font-size: 14px; }
.footer li a:hover { color: var(--primary); }
.footer-brand { font-weight: 800; font-size: 18px; display: flex; align-items: center; gap: 8px; margin-bottom: 12px; }
.footer p { color: var(--ink-soft); font-size: 14px; }
.footer-bottom { margin-top: 34px; padding-top: 20px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; font-size: 13px; color: var(--muted); }

/* ---------- Download page ---------- */
.dl-page { padding: 70px 0; }
.dl-card { max-width: 640px; margin: 0 auto; border: 1px solid var(--line); border-radius: 20px; padding: 40px 34px; text-align: center; background: var(--card); box-shadow: var(--shadow); }
.dl-card .icon { width: 58px; height: 58px; border-radius: 16px; background: linear-gradient(135deg,#ff7028,#ff9d3c); display: grid; place-items: center; color: #fff; margin: 0 auto 18px; }
.dl-card h1 { font-size: 26px; font-weight: 800; }
.dl-card .ver { display:inline-block; margin: 12px 0 18px; height: 26px; padding: 0 12px; border-radius: 999px; background: var(--primary-soft); color: var(--primary); font-weight: 700; font-size: 13px; }
.dl-card .btn { width: 100%; justify-content: center; height: 52px; font-size: 16px; }
.dl-meta { margin-top: 18px; font-size: 13px; color: var(--muted); display: grid; gap: 6px; }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .feature, .feature.rev { grid-template-columns: 1fr; gap: 28px; }
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero { padding: 50px 0 40px; }
  .section { padding: 60px 0; }
}
@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; }
  .container { padding: 0 18px; }
}