:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fc;
  --line: #e5e9f2;
  --line-strong: #d5dcea;
  --fg: #1c2433;
  --lead: #3a4560;
  --dim: #6b7793;
  --acc: #2563eb;
  --acc-soft: #eaf1ff;
  --code-bg: #f4f6fb;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--acc); text-decoration: none; }
a:hover { text-decoration: underline; }

.top {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  padding: 13px 28px;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.brand { color: #101828; font-weight: 800; letter-spacing: .3px; font-size: 17px; }
.brand span { color: var(--acc); font-weight: 600; }

.topnav { display: flex; gap: 20px; font-size: 14px; }
.topnav a { color: var(--lead); }
.topnav a:hover { color: var(--acc); }

.layout {
  display: flex; gap: 40px;
  max-width: 1240px; margin: 0 auto; padding: 30px 28px 70px;
  align-items: flex-start;
}

.side {
  position: sticky; top: 70px;
  width: 220px; flex: 0 0 220px;
  max-height: calc(100vh - 96px); overflow: auto;
  padding-right: 6px;
  scrollbar-width: thin;
  scrollbar-color: #d7deea transparent;
  border-right: 1px solid var(--line);
}

.side .grp {
  margin: 20px 0 6px;
  font-size: 12px; letter-spacing: 1.6px;
  color: var(--dim); font-weight: 700;
}

.side ul { list-style: none; margin: 0; padding: 0; }
.side li { margin: 1px 0; }
.side li a {
  display: block; padding: 6px 10px; border-radius: 6px;
  color: var(--lead); font-size: 14.5px;
}
.side li a:hover { background: var(--bg-soft); text-decoration: none; }
.side li a.on {
  background: var(--acc-soft);
  color: #1746c4; font-weight: 700;
}

.doc {
  flex: 1 1 auto; min-width: 0;
  padding: 4px 0 10px;
  max-width: 860px;
}

.doc h1 {
  margin: 0 0 16px;
  font-size: 33px; line-height: 1.3; color: #101828;
  font-weight: 800;
}

.doc h2 {
  margin: 36px 0 12px; font-size: 22px; color: #101828;
  padding-bottom: 8px; border-bottom: 1px solid var(--line);
}

.doc h3 { margin: 24px 0 8px; font-size: 17.5px; color: #1c2433; }

.doc p { margin: 10px 0; color: var(--lead); }

.doc ul, .doc ol { padding-left: 22px; color: var(--lead); }
.doc li { margin: 4px 0; }
.doc li > strong { color: #101828; }

.doc code {
  background: var(--code-bg);
  border: 1px solid var(--line);
  color: #c7254e;
  padding: 1px 6px; border-radius: 5px;
  font-family: Consolas, "Cascadia Mono", monospace; font-size: 13.5px;
}

.doc pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 10px; padding: 14px 16px; overflow: auto;
}
.doc pre code { background: none; border: 0; color: #26304a; padding: 0; font-size: 13.5px; }

.doc blockquote {
  margin: 16px 0; padding: 10px 16px;
  border-left: 3px solid var(--acc);
  background: var(--acc-soft);
  color: #22406f; border-radius: 0 8px 8px 0;
}
.doc blockquote p { color: #22406f; margin: 4px 0; }

.doc table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14.5px; }
.doc th, .doc td { border: 1px solid var(--line-strong); padding: 9px 12px; text-align: left; }
.doc th { background: var(--bg-soft); color: #101828; font-weight: 700; }
.doc tr:nth-child(even) td { background: #fbfcfe; }

.doc img {
  display: block;
  max-width: 100%;
  max-height: 520px;
  width: auto;
  border-radius: 8px;
  margin: 16px auto;
  border: 1px solid var(--line);
  background: #fff;
}

.foot {
  margin-top: 48px; padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 13px; color: var(--dim);
}

@media (max-width: 900px) {
  .layout { flex-direction: column; }
  .side {
    position: static; width: 100%; flex: none;
    max-height: none; border-right: 0; border-bottom: 1px solid var(--line);
    padding-bottom: 12px;
  }
}

.side::-webkit-scrollbar { width: 6px; }
.side::-webkit-scrollbar-thumb { background: #d7deea; border-radius: 3px; }
.side::-webkit-scrollbar-track { background: transparent; }