/* PDGait 官网样式 —— 无外部依赖，纯静态 */
:root {
  --teal: #1BA3A9;
  --teal-dark: #12838A;
  --teal-light: #E6F6F6;
  --ink: #0F2A2E;
  --ink-2: #37585D;
  --muted: #6B858A;
  --line: #DCE8E9;
  --bg: #F7FAFA;
  --white: #FFFFFF;
  --warm: #F89E4E;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 42, 46, .07);
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--teal-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ---------- 顶栏 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(247, 250, 250, .86);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 24px;
  height: 64px; display: flex; align-items: center; gap: 28px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--ink); letter-spacing: .2px; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.brand:hover { text-decoration: none; }
.brand small { display: block; font-weight: 400; font-size: 11px; color: var(--muted); letter-spacing: .6px; line-height: 1.2; }
.nav-links { display: flex; gap: 22px; margin-left: auto; align-items: center; }
.nav-links a { color: var(--ink-2); font-size: 14.5px; }
.nav-links a:hover { color: var(--teal-dark); text-decoration: none; }
.nav-links a.active { color: var(--teal-dark); font-weight: 600; }
.nav-cta {
  background: var(--teal); color: #fff !important; padding: 8px 18px;
  border-radius: 999px; font-size: 14px; font-weight: 600;
}
.nav-cta:hover { background: var(--teal-dark); text-decoration: none; }
.nav-toggle { display: none; background: none; border: 0; font-size: 22px; color: var(--ink); cursor: pointer; }

/* ---------- Hero ---------- */
.hero {
  background:
    radial-gradient(900px 420px at 80% -10%, rgba(68, 190, 181, .22), transparent 60%),
    linear-gradient(160deg, #0C2A2E 0%, #10383C 55%, #145055 100%);
  color: #fff; overflow: hidden;
}
.hero-inner {
  max-width: var(--max); margin: 0 auto; padding: 84px 24px 76px;
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: center;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12.5px; letter-spacing: 1.6px; text-transform: uppercase;
  color: #8FDCD8; margin-bottom: 18px;
}
.eyebrow::before { content: ""; width: 22px; height: 1px; background: #8FDCD8; }
.hero h1 { font-size: 46px; line-height: 1.22; margin: 0 0 20px; letter-spacing: -.5px; font-weight: 700; }
.hero h1 em { font-style: normal; color: #6FD3CF; }
.hero p.lead { font-size: 17.5px; color: #C9E4E3; margin: 0 0 30px; max-width: 560px; }
.btn-row { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 999px; font-weight: 600; font-size: 15px;
  transition: transform .15s ease, background .15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--teal); color: #fff; }
.btn-primary:hover { background: #22b6bc; }
.btn-ghost { border: 1px solid rgba(255,255,255,.28); color: #EAF7F6; }
.btn-ghost:hover { background: rgba(255,255,255,.08); }
.hero-note { margin-top: 18px; font-size: 12.5px; color: #8FB3B4; }
.hero-note strong { color: #B9DCDA; font-weight: 600; }

/* Hero 右侧示意卡 */
.device {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 22px; padding: 22px;
  box-shadow: 0 30px 60px rgba(0,0,0,.25);
  backdrop-filter: blur(6px);
}
.device-head { display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: #9FC9C8; margin-bottom: 16px; letter-spacing: .4px; }
.dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: #57E0B5; margin-right: 6px; box-shadow: 0 0 0 3px rgba(87,224,181,.16); }
.device-num { font-size: 40px; font-weight: 700; letter-spacing: -1px; }
.device-num span { font-size: 15px; color: #9FC9C8; font-weight: 400; margin-left: 4px; }
.device-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 18px; }
.device-cell { background: rgba(255,255,255,.05); border-radius: 12px; padding: 12px 14px; }
.device-cell b { display: block; font-size: 19px; font-weight: 600; }
.device-cell i { font-style: normal; font-size: 11.5px; color: #9FC9C8; }
.spark { margin-top: 16px; height: 56px; width: 100%; }

/* ---------- 通用区块 ---------- */
.section { padding: 76px 0; }
.section.alt { background: var(--white); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head h2 { font-size: 31px; line-height: 1.35; margin: 0 0 12px; letter-spacing: -.3px; }
.section-head p { margin: 0; color: var(--muted); font-size: 16px; }
.kicker { font-size: 12.5px; letter-spacing: 1.6px; text-transform: uppercase; color: var(--teal-dark); font-weight: 700; margin-bottom: 10px; }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.card {
  background: var(--white); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
}
.card h3 { margin: 14px 0 8px; font-size: 19px; }
.card p { margin: 0; color: var(--ink-2); font-size: 14.5px; }
.icon {
  width: 42px; height: 42px; border-radius: 12px; background: var(--teal-light);
  display: flex; align-items: center; justify-content: center; color: var(--teal-dark);
  font-size: 20px; font-weight: 700;
}

.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.stat { text-align: center; padding: 24px 12px; }
.stat b { display: block; font-size: 32px; color: var(--teal-dark); letter-spacing: -1px; line-height: 1.2; }
.stat span { font-size: 13px; color: var(--muted); }

.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; counter-reset: step; }
.flow-item { position: relative; background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.flow-item::before {
  counter-increment: step; content: "0" counter(step);
  font-size: 12px; font-weight: 700; color: var(--teal); letter-spacing: 1px;
}
.flow-item h3 { font-size: 16px; margin: 6px 0 6px; }
.flow-item p { margin: 0; font-size: 13.5px; color: var(--muted); }

/* 指标表 */
.metric-table { width: 100%; border-collapse: collapse; background: var(--white); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.metric-table th, .metric-table td { text-align: left; padding: 14px 18px; border-bottom: 1px solid var(--line); font-size: 14.5px; vertical-align: top; }
.metric-table th { background: var(--teal-light); color: var(--ink); font-size: 13px; letter-spacing: .4px; }
.metric-table tr:last-child td { border-bottom: 0; }
.metric-table td:first-child { font-weight: 600; white-space: nowrap; }
.metric-table td:nth-child(2) { color: var(--muted); font-family: ui-monospace, "SFMono-Regular", Consolas, monospace; font-size: 13px; }

/* 提示条 */
.callout {
  border-left: 3px solid var(--teal); background: var(--teal-light);
  padding: 16px 20px; border-radius: 0 10px 10px 0; color: var(--ink-2); font-size: 14.5px;
}
.callout.warn { border-left-color: var(--warm); background: #FFF4E8; }
.callout strong { color: var(--ink); }

/* CTA */
.cta {
  background: linear-gradient(135deg, #10383C, #145055);
  color: #fff; border-radius: 22px; padding: 52px; text-align: center;
}
.cta h2 { margin: 0 0 12px; font-size: 30px; }
.cta p { margin: 0 auto 26px; color: #C9E4E3; max-width: 560px; }

/* 页脚 */
.footer { border-top: 1px solid var(--line); background: var(--white); padding: 48px 0 34px; margin-top: 20px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px; }
.footer h4 { font-size: 13px; letter-spacing: .6px; color: var(--muted); margin: 0 0 14px; font-weight: 600; }
.footer a { display: block; color: var(--ink-2); font-size: 14px; margin-bottom: 9px; }
.footer p { color: var(--muted); font-size: 13px; margin: 14px 0 0; }
.footer-bottom { border-top: 1px solid var(--line); margin-top: 34px; padding-top: 22px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: 12.5px; }

/* 内容页 */
.page-head { padding: 64px 0 40px; background: linear-gradient(180deg, var(--teal-light), var(--bg)); border-bottom: 1px solid var(--line); }
.page-head h1 { font-size: 38px; margin: 0 0 12px; letter-spacing: -.5px; }
.page-head p { margin: 0; color: var(--ink-2); max-width: 680px; }
.prose { max-width: 820px; }
.prose h2 { font-size: 23px; margin: 44px 0 12px; }
.prose h3 { font-size: 18px; margin: 28px 0 8px; }
.prose p, .prose li { color: var(--ink-2); font-size: 15.5px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin-bottom: 8px; }
.prose .meta { color: var(--muted); font-size: 13px; }

/* 下载页 */
.download-card { display: grid; grid-template-columns: 1.3fr .7fr; gap: 32px; align-items: center; }
.download-card .version { font-size: 13px; color: var(--muted); letter-spacing: .3px; }
.download-card h2 { font-size: 28px; margin: 6px 0 10px; }
.meta-list { list-style: none; padding: 0; margin: 18px 0 0; }
.meta-list li { display: flex; justify-content: space-between; border-bottom: 1px dashed var(--line); padding: 9px 0; font-size: 14px; color: var(--ink-2); }
.meta-list li span:last-child { color: var(--ink); font-family: ui-monospace, Consolas, monospace; font-size: 13px; }

/* 响应式 */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; padding: 60px 24px; }
  .hero h1 { font-size: 34px; }
  .grid-3, .grid-2, .flow, .stats { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .download-card { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: var(--white); border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: flex-start; padding: 16px 24px; gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 8px 0; width: 100%; }
  .nav-toggle { display: block; margin-left: auto; }
  .hero h1 { font-size: 29px; }
  .grid-3, .grid-2, .flow, .stats, .footer-grid { grid-template-columns: 1fr; }
  .section { padding: 54px 0; }
  .cta { padding: 34px 22px; }
  .cta h2 { font-size: 24px; }
  .page-head h1 { font-size: 29px; }
  .metric-table th:nth-child(2), .metric-table td:nth-child(2) { display: none; }
}