:root {
  --indigo: #6366f1;
  --indigo-600: #4f46e5;
  --violet: #8b5cf6;
  --cyan: #22d3ee;
  --ink: #111327;
  --text: #1f2430;
  --muted: #667085;
  --line: #e8eaf1;
  --bg: #ffffff;
  --bg-soft: #f7f8fc;
  --radius: 16px;
  --shadow: 0 10px 40px rgba(20,22,30,0.10);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; color: var(--text); background: var(--bg); -webkit-font-smoothing: antialiased; line-height: 1.6; }
a { color: inherit; text-decoration: none; }
h1,h2,h3 { margin: 0; line-height: 1.15; }
img { max-width: 100%; display: block; }
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 820px; }

/* nav */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 50; background: rgba(255,255,255,0.86); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.nav-inner { display: flex; align-items: center; gap: 28px; height: 64px; }
.brand { display: flex; align-items: center; gap: 8px; font-size: 17px; }
.brand-logo { font-size: 20px; }
.brand-sub { color: var(--muted); font-size: 13px; font-weight: 400; }
.nav-links { display: flex; gap: 22px; margin-left: auto; font-size: 14.5px; color: var(--muted); }
.nav-links a:hover { color: var(--indigo); }
.nav .btn-sm { margin-left: 8px; }
.nav-toggle { display: none; margin-left: auto; background: none; border: none; font-size: 20px; cursor: pointer; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; padding: 12px 22px; border-radius: 12px; font-size: 15px; font-weight: 600; border: 1px solid transparent; cursor: pointer; transition: transform .15s ease, box-shadow .15s ease, background .15s; }
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--indigo); color: #fff; box-shadow: 0 8px 24px rgba(99,102,241,0.35); }
.btn-primary:hover { background: var(--indigo-600); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--indigo); color: var(--indigo); }
.btn-outline { background: transparent; color: #fff; border-color: rgba(255,255,255,0.5); }
.btn-white { background: #fff; color: var(--indigo); }
.btn-sm { padding: 9px 16px; font-size: 14px; }
.btn-block { width: 100%; }

/* hero */
.hero { padding: 130px 0 70px; position: relative; overflow: hidden; background: var(--ink); color: #fff; }
.hero::before { content: ""; position: absolute; inset: 0; background: radial-gradient(700px 400px at 15% 20%, rgba(99,102,241,0.35), transparent 60%), radial-gradient(600px 400px at 90% 90%, rgba(34,211,238,0.20), transparent 60%); }
.hero-inner { position: relative; display: grid; grid-template-columns: 1fr 0.9fr; gap: 48px; align-items: center; }
.hero-text .eyebrow { color: #a5b0c8; font-size: 14px; letter-spacing: 0.2em; }
.hero-text h1 { font-size: 58px; font-weight: 800; letter-spacing: -0.02em; margin: 14px 0 18px; }
.hero-text .lead { color: #c9d2e3; font-size: 18px; max-width: 480px; }
.hero-cta { display: flex; gap: 12px; margin-top: 26px; flex-wrap: wrap; }
.hero-meta { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 26px; color: #a5b0c8; font-size: 13.5px; }
.hero-visual img { border-radius: 18px; box-shadow: 0 30px 80px rgba(0,0,0,0.45); transform: rotate(-2deg); }

/* sections */
.section { padding: 76px 0; }
.section.alt { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 44px; }
.sec-eyebrow { color: var(--indigo); font-weight: 700; font-size: 13px; letter-spacing: 0.15em; text-transform: uppercase; }
.section-head h2 { font-size: 34px; margin: 8px 0 10px; }
.section-head p { color: var(--muted); margin: 0; }

/* features */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card { padding: 22px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; transition: transform .18s, box-shadow .18s; }
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.card-ico { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 20px; background: var(--bg-soft); border: 1px solid var(--line); margin-bottom: 14px; }
.card h3 { font-size: 17px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14px; margin: 0; }
.card code { background: var(--bg-soft); padding: 1px 5px; border-radius: 5px; font-size: 12.5px; color: var(--indigo); }

/* pricing */
.pricing { align-items: stretch; }
.price-card { position: relative; padding: 26px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; display: flex; flex-direction: column; }
.price-card.popular { border: 2px solid var(--indigo); box-shadow: 0 20px 60px rgba(99,102,241,0.16); transform: translateY(-6px); }
.price-badge { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--indigo); color: #fff; padding: 4px 14px; border-radius: 20px; font-size: 12px; font-weight: 700; }
.price-name { font-size: 15px; font-weight: 700; color: var(--muted); }
.price-num { font-size: 42px; font-weight: 800; margin: 8px 0 2px; letter-spacing: -0.02em; }
.price-per { color: var(--muted); font-size: 13px; margin-bottom: 18px; }
.price-card ul { list-style: none; padding: 0; margin: 0 0 22px; flex: 1; }
.price-card li { padding: 7px 0; font-size: 14px; color: #333c48; border-bottom: 1px dashed var(--line); }
.price-card li::before { content: "✓ "; color: var(--indigo); font-weight: 700; }

/* changelog timeline */
.timeline { list-style: none; padding: 0; margin: 0; position: relative; }
.timeline::before { content: ""; position: absolute; left: 108px; top: 0; bottom: 0; width: 2px; background: var(--line); }
.tl { position: relative; padding: 0 0 26px 0; }
.tl-ver { position: absolute; left: 0; width: 96px; text-align: right; font-weight: 800; color: var(--indigo); font-size: 16px; }
.tl-date { position: absolute; left: 128px; top: 22px; color: var(--muted); font-size: 13px; }
.tl-body { margin-left: 160px; padding: 8px 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; font-size: 14.5px; }
.tl-body b { color: var(--ink); }

/* docs */
.code-demo { max-width: 760px; margin: 0 auto; border: 1px solid var(--line); border-radius: 14px; overflow: hidden; background: #0f1222; }
.code-head { display: flex; justify-content: space-between; align-items: center; padding: 12px 16px; background: rgba(255,255,255,0.06); color: #c9d2e3; font-size: 13px; }
.code-head button { background: rgba(255,255,255,0.12); border: none; color: #fff; padding: 5px 12px; border-radius: 8px; cursor: pointer; font-size: 12.5px; }
.code-demo pre { margin: 0; padding: 18px; overflow: auto; }
.code-demo code { color: #e2e8f0; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 13px; white-space: pre; }
.doc-links { text-align: center; margin-top: 18px; }
.doc-links .link { color: var(--indigo); font-weight: 600; }
.doc-links .link-sep { margin: 0 10px; color: var(--line); }

/* cta */
.cta { background: linear-gradient(120deg, var(--indigo), var(--violet)); color: #fff; padding: 70px 0; }
.cta-inner { text-align: center; }
.cta h2 { font-size: 32px; margin-bottom: 10px; }
.cta p { color: rgba(255,255,255,0.85); margin: 0 0 26px; }
.cta-btns { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* footer */
.footer { padding: 40px 0; background: var(--ink); color: #9aa4bd; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 20px; align-items: center; justify-content: space-between; font-size: 13.5px; }
.footer-brand { font-size: 15px; color: #e2e8f0; }
.footer-links { display: flex; gap: 18px; }
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: 12.5px; }

/* responsive */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; gap: 40px; }
  .hero-text .lead, .hero-meta { margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-text h1 { font-size: 44px; }
  .grid-3 { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .grid-3 { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav.open .nav-links { display: flex; position: absolute; top: 64px; left: 0; right: 0; flex-direction: column; background: #fff; padding: 16px 24px; border-bottom: 1px solid var(--line); }
  .nav-toggle { display: block; }
  .nav .btn-sm { display: none; }
  .hero-text h1 { font-size: 38px; }
  .hero { padding: 100px 0 50px; }
  .tl-ver { width: auto; position: static; display: block; text-align: left; margin-bottom: 4px; }
  .tl-date { position: static; margin-bottom: 4px; }
  .tl-body { margin-left: 0; }
  .timeline::before { display: none; }
}