/*
 * 公开内容站的样式：单文件、无外部依赖、无字体请求。
 * 目标是首屏快、可读性好、在手机上不横向滚动——Core Web Vitals 与「内容可读」
 * 对搜索排名和 AI 摘要都有直接影响。
 */
:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --text: #14203a;
  --muted: #5b6b88;
  --line: #e2e8f2;
  --brand: #1089d3;
  --brand-dark: #0b6ea9;
  --accent: #0f9d76;
  --warn: #b45309;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 32, 58, 0.06), 0 12px 32px -18px rgba(20, 32, 58, 0.35);
  --maxw: 1080px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
main { overflow-wrap: anywhere; }
a:focus-visible, summary:focus-visible { outline: 2px solid var(--brand-dark); outline-offset: 3px; }
img { max-width: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Source Han Sans SC", sans-serif;
}
a { color: var(--brand-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

header.site {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--line);
}
header.site .bar { display: flex; align-items: center; gap: 18px; min-height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); flex: 0 0 auto; }
.brand img { width: 26px; height: 26px; border-radius: 7px; }
.brand small { color: var(--muted); font-weight: 500; font-size: 12px; }
nav.top { display: flex; flex-wrap: wrap; gap: 4px 14px; margin-left: auto; font-size: 14px; }
nav.top a { color: var(--muted); padding: 4px 0; }
nav.top a[aria-current="page"] { color: var(--text); font-weight: 600; }
.btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 9px 16px; border-radius: 10px;
  background: var(--brand); color: #fff !important; font-weight: 600; font-size: 14px;
  border: 1px solid transparent; text-decoration: none !important; white-space: nowrap;
}
.btn:hover { background: var(--brand-dark); }
.btn.ghost { background: transparent; color: var(--text) !important; border-color: var(--line); }
header.site .btn { flex: 0 0 auto; }

main { padding: 34px 0 60px; }
.crumbs { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.crumbs a { color: var(--muted); }
.hero {
  background: linear-gradient(140deg, #eaf4fd 0%, #f7fbff 45%, #eefaf5 100%);
  border: 1px solid var(--line); border-radius: 20px; padding: 30px 28px; margin-bottom: 26px;
}
h1 { font-size: clamp(26px, 4.2vw, 38px); line-height: 1.3; margin: 0 0 14px; letter-spacing: -0.4px; }
h2 { font-size: clamp(20px, 2.8vw, 25px); line-height: 1.4; margin: 36px 0 12px; }
h3 { font-size: 17px; margin: 24px 0 8px; }
p { margin: 0 0 14px; }
.lead { font-size: 17px; color: #29364f; }
.meta { font-size: 13px; color: var(--muted); display: flex; flex-wrap: wrap; gap: 8px 16px; margin-top: 14px; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }

.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr)); margin: 18px 0; }
.grid .card h3 { margin-top: 0; }
.grid .card p { margin-bottom: 8px; color: #2c3a56; font-size: 15px; }
.grid .card .more { font-size: 14px; font-weight: 600; }

ul, ol { margin: 0 0 14px; padding-left: 22px; }
li { margin-bottom: 6px; }
ul.tight li, ol.tight li { margin-bottom: 2px; }
table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 15px; background: var(--surface); }
caption { text-align: left; color: var(--muted); font-size: 13px; padding: 0 0 6px; }
th, td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
th { background: #f2f6fc; font-weight: 600; }
.table-scroll { overflow-x: auto; }
code { background: #eef2f8; border-radius: 5px; padding: 1px 5px; font-size: 0.92em; }

.note {
  border-left: 3px solid var(--brand); background: #eef7fe; border-radius: 10px;
  padding: 12px 16px; margin: 16px 0; font-size: 15px;
}
.note.warn { border-color: var(--warn); background: #fff7ed; }
.quote { border-left: 3px solid var(--line); color: var(--muted); padding: 4px 16px; margin: 16px 0; }
.quote cite { display: block; font-size: 13px; font-style: normal; margin-top: 6px; }

.facts { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); margin: 18px 0; }
.facts div { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; }
.facts b { display: block; font-size: 19px; }
.facts span { font-size: 13px; color: var(--muted); }

.steps { counter-reset: step; list-style: none; padding-left: 0; }
.steps > li { counter-increment: step; position: relative; padding-left: 42px; margin-bottom: 14px; }
.steps > li::before {
  content: counter(step); position: absolute; left: 0; top: 1px;
  width: 28px; height: 28px; border-radius: 50%; background: var(--brand); color: #fff;
  display: grid; place-items: center; font-size: 14px; font-weight: 700;
}
.steps b { display: block; }

details.faq { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 12px 16px; margin-bottom: 10px; }
details.faq summary { cursor: pointer; font-weight: 600; }
details.faq[open] summary { margin-bottom: 8px; }
details.faq p:last-child { margin-bottom: 0; }

/* 可直接引用的结论：给人和机器一个「一句话一条事实」的可摘取区块 */
.keyfacts {
  background: #f0fbf6; border: 1px solid #cdeadf; border-radius: 14px;
  padding: 18px 22px; margin: 26px 0;
}
.keyfacts h2 { margin: 0 0 10px; font-size: 17px; color: #0b6b52; }
.keyfacts ul { margin: 0; padding-left: 20px; }
.keyfacts li { margin-bottom: 8px; }

/* 术语表：定义用词典型排版，便于机器识别「术语 → 定义」 */
dl.terms { margin: 18px 0; background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 8px 22px; }
dl.terms dt { font-weight: 700; margin-top: 14px; }
dl.terms dd { margin: 4px 0 0; color: #2c3a56; }
dl.terms dt:target, dl.terms dt:target + dd { background: #fff9e6; }

/* 更新日志：时间线比纯列表更能让「最近更新了什么」一眼看清 */
ol.timeline { list-style: none; padding-left: 0; margin: 18px 0; border-left: 2px solid var(--line); }
ol.timeline li { position: relative; padding: 0 0 16px 20px; margin: 0; }
ol.timeline li::before {
  content: ""; position: absolute; left: -7px; top: 7px; width: 10px; height: 10px;
  border-radius: 50%; background: var(--brand);
}
ol.timeline time { display: block; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }

ul.sources { font-size: 14px; color: var(--muted); }

.cta {
  background: linear-gradient(135deg, #0e76b8, #0f9d76); color: #fff;
  border-radius: 18px; padding: 24px 26px; margin: 30px 0;
}
.cta h2, .cta h3 { color: #fff; margin-top: 0; }
.cta p { color: rgba(255, 255, 255, 0.92); }
.cta .btn { background: #fff; color: var(--brand-dark) !important; }
.cta .btn.ghost { background: transparent; color: #fff !important; border-color: rgba(255, 255, 255, 0.6); }

.related { margin-top: 34px; }
.toc { margin: 22px 0 6px; }
.toc h2 { margin-top: 0; font-size: 18px; }
.toc ul { list-style: none; padding-left: 0; display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }
.toc li { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; margin: 0; }
.toc li a { font-weight: 600; }
.toc li span { display: block; color: var(--muted); font-size: 13px; line-height: 1.6; }
.related ul { list-style: none; padding-left: 0; display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); }
.related li { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; margin: 0; }
.related li a { font-weight: 600; }
.related li span { display: block; color: var(--muted); font-size: 13px; line-height: 1.6; }

footer.site { border-top: 1px solid var(--line); background: var(--surface); padding: 30px 0 40px; font-size: 14px; color: var(--muted); }
footer.site .cols { display: grid; gap: 20px; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); }
footer.site h3 { font-size: 14px; color: var(--text); margin: 0 0 8px; }
footer.site ul { list-style: none; padding: 0; margin: 0; }
footer.site li { margin-bottom: 4px; }
footer.site .legal { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--line); font-size: 13px; }

@media (max-width: 720px) {
  header.site .bar { flex-wrap: wrap; padding-top: 8px; padding-bottom: 8px; gap: 8px 12px; }
  .brand { flex-wrap: wrap; gap: 4px 8px; }
  nav.top { margin-left: 0; width: 100%; order: 3; }
  .hero { padding: 22px 18px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }