:root {
  --bg: #f4f6f9;
  --bg-2: #eef1f6;
  --panel: #ffffff;
  --panel-2: #f8fafc;
  --line: #e5e9f0;
  --line-2: #d7dde8;
  --text: #141b2a;
  --muted: #5c6b82;
  --muted-2: #8a97a8;
  --cyan: #2563eb;
  --accent: #1d4ed8;
  --amber: #b45309;
  --danger: #dc2626;
  --radius: 10px;
  --maxw: 1120px;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Courier New", monospace;
  --sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

/* 顶部导航 */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 26px;
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  width: 30px; height: 30px;
  border-radius: 7px;
  display: grid; place-items: center;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
  color: #fff;
  background: var(--cyan);
}
.brand-name { font-weight: 600; letter-spacing: .2px; font-size: 15px; }
.brand-name small { color: var(--muted-2); font-weight: 400; margin-left: 6px; font-size: 11px; letter-spacing: .6px; }

.nav-links { display: flex; gap: 22px; margin-left: auto; align-items: center; }
.nav-links a { color: var(--muted); font-size: 14px; transition: color .15s; }
.nav-links a:hover, .nav-links a.active { color: var(--text); }

.hero-offer {
  display: inline-flex; align-items: center; gap: 18px;
  margin-top: 32px;
  padding: 13px 24px;
  background: var(--panel);
  border: 1px solid var(--line-2);
  border-radius: 10px;
}
.hero-offer .offer-price { font-size: 18px; font-weight: 700; color: var(--cyan); }
.hero-offer .offer-sep { width: 1px; height: 22px; background: var(--line-2); }
.hero-offer .offer-q { font-size: 14px; color: var(--muted); }
.hero-offer .offer-q b { color: var(--text); font-family: var(--mono); font-weight: 600; }

.nav-toggle { display: none; background: none; border: 0; color: var(--text); font-size: 22px; cursor: pointer; }

/* 主容器 */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }

/* Hero */
.hero { padding: 88px 0 56px; text-align: center; }
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 12px; color: var(--muted);
  border: 1px solid var(--line-2); background: var(--panel);
  padding: 5px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero-eyebrow .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--cyan); }

.hero h1 {
  font-size: clamp(32px, 5.4vw, 52px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -.5px;
  margin-bottom: 18px;
}
.hero h1 .accent { color: var(--cyan); }

.hero-sub {
  color: var(--muted);
  font-size: clamp(15px, 2vw, 17px);
  max-width: 620px;
  margin: 0 auto 30px;
}

.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 22px; border-radius: 8px;
  font-size: 14px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer;
  transition: background .12s, border-color .12s, color .12s;
}
.btn-primary { color: #fff; background: var(--cyan); }
.btn-primary:hover { background: var(--accent); }
.btn-ghost { color: var(--cyan); background: var(--panel); border-color: var(--line-2); }
.btn-ghost:hover { border-color: var(--cyan); }

/* 区块 */
.section { padding: 64px 0; }
.section-head { text-align: center; margin-bottom: 40px; }
.section-head h2 { font-size: clamp(22px, 3vw, 30px); font-weight: 700; letter-spacing: -.3px; }
.section-head p { color: var(--muted); margin-top: 10px; max-width: 560px; margin-left: auto; margin-right: auto; }

/* 功能卡片 */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 22px;
  transition: border-color .15s;
}
.card:hover { border-color: var(--line-2); }
.card-icon {
  width: 40px; height: 40px; border-radius: 8px;
  display: grid; place-items: center; margin-bottom: 16px;
  font-size: 18px;
  background: #eef4ff;
  color: var(--cyan);
}
.card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 13.5px; }
.card ul { list-style: none; margin-top: 12px; }
.card ul li { color: var(--muted); font-size: 13px; padding-left: 16px; position: relative; margin-top: 6px; }
.card ul li::before { content: "—"; position: absolute; left: 0; color: var(--line-2); }

/* 特性双栏 */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.split .txt h2 { font-size: 26px; font-weight: 700; margin-bottom: 14px; }
.split .txt p { color: var(--muted); margin-bottom: 12px; font-size: 14px; }
.split .code {
  background: var(--panel-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px;
  font-family: var(--mono); font-size: 12.5px; line-height: 1.8;
  overflow: auto;
}

/* 步骤 */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.step { padding: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.step-num { font-family: var(--mono); color: var(--cyan); font-size: 13px; font-weight: 700; }
.step h4 { margin: 8px 0 6px; font-size: 15px; }
.step p { color: var(--muted); font-size: 13px; }

/* 页脚 */
.footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--muted-2); font-size: 13px; background: var(--panel); }
.footer-inner { display: flex; justify-content: space-between; gap: 18px; flex-wrap: wrap; }
.footer a { color: var(--muted); }
.footer a:hover { color: var(--text); }
/* 免责声明与备案信息各占一整行，原有的左右两栏布局不受影响 */
.footer-disclaimer { flex-basis: 100%; color: var(--muted-2); font-size: 12px; line-height: 1.8; border-top: 1px solid var(--line); padding-top: 14px; }
.footer-meta { flex-basis: 100%; display: flex; flex-wrap: wrap; gap: 16px; font-size: 12px; color: var(--muted-2); }
.footer-meta span:empty { display: none; }

/* 产品介绍页布局 */
.doc-wrap { display: grid; grid-template-columns: 230px 1fr; gap: 40px; padding: 44px 0 72px; }
.doc-side { position: sticky; top: 84px; align-self: start; }
.doc-side .group { margin-bottom: 22px; }
.doc-side .group h4 { font-size: 12px; letter-spacing: 1px; color: var(--muted-2); margin-bottom: 8px; }
.doc-side a { display: block; padding: 6px 12px; border-radius: 7px; color: var(--muted); font-size: 14px; border-left: 2px solid transparent; }
.doc-side a:hover { color: var(--text); }
.doc-side a.active { color: var(--cyan); border-left-color: var(--cyan); background: #eef4ff; }
.doc-main { min-width: 0; }
.doc-main h1 { font-size: 30px; font-weight: 700; margin-bottom: 6px; }
.doc-main .lead { color: var(--muted); font-size: 15px; margin-bottom: 36px; }
.doc-main h2 { font-size: 22px; font-weight: 700; margin: 42px 0 14px; padding-top: 18px; border-top: 1px solid var(--line); }
.doc-main h2:first-of-type { border-top: 0; padding-top: 0; margin-top: 0; }
.doc-main h3 { font-size: 17px; font-weight: 600; margin: 24px 0 10px; color: var(--cyan); }
.doc-main p { color: var(--muted); margin-bottom: 14px; }
.doc-main ul, .doc-main ol { color: var(--muted); padding-left: 22px; margin-bottom: 14px; }
.doc-main li { margin-top: 7px; }
.doc-main strong { color: var(--text); }
.doc-main code {
  font-family: var(--mono); font-size: 13px;
  background: #eef4ff; color: var(--cyan);
  padding: 2px 7px; border-radius: 6px;
}
.doc-main pre {
  background: var(--panel-2); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px; overflow: auto;
  font-family: var(--mono); font-size: 13px; line-height: 1.8; margin: 16px 0;
  color: #24324a;
}
.doc-main table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14px; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.doc-main th, .doc-main td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
.doc-main th { color: var(--muted-2); font-weight: 500; font-size: 13px; background: var(--panel-2); }
.doc-main td { color: var(--text); }

/* 徽章 */
.tag { display: inline-block; padding: 3px 10px; border-radius: 6px; font-size: 12px; font-family: var(--mono); }
.tag-ok { color: var(--accent); background: #eef4ff; border: 1px solid #cddbfc; }
.tag-warn { color: var(--amber); background: #fdf3e2; border: 1px solid #f3d9a8; }

/* 响应式 */
@media (max-width: 920px) {
  .cards { grid-template-columns: 1fr 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .split { grid-template-columns: 1fr; }
  .doc-wrap { grid-template-columns: 1fr; }
  .doc-side { position: static; display: none; }
}
@media (max-width: 620px) {
  .cards { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-toggle { display: block; margin-left: auto; }
  .nav-links.open { display: flex; flex-direction: column; position: absolute; top: 60px; left: 0; right: 0; background: var(--panel); border-bottom: 1px solid var(--line); padding: 16px 22px; gap: 14px; }
  .hero { padding: 60px 0 36px; }
}

.reveal { opacity: 0; transform: translateY(14px); transition: opacity .45s ease, transform .45s ease; }
.reveal.in { opacity: 1; transform: none; }