:root {
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --display: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --max: 980px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
main { flex: 1; width: min(var(--max), calc(100% - 40px)); margin: 0 auto; padding: 32px 0 64px; }

.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 5;
}
.brand {
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink);
  text-decoration: none;
  font-size: 18px;
}
.brand:hover { text-decoration: none; color: var(--accent); }
nav { display: flex; flex-wrap: wrap; gap: 8px 18px; }
nav a { color: var(--muted); text-decoration: none; font-size: 14px; }
nav a:hover, nav a.active { color: var(--ink); text-decoration: none; }

.foot {
  border-top: 1px solid var(--line);
  padding: 24px 20px 36px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}
.foot p { margin: 4px 0; }
.muted { color: var(--muted); }

h1, h2, h3 { font-family: var(--display); line-height: 1.25; }
h1 { font-size: 36px; margin: 0 0 12px; letter-spacing: -0.03em; }
h2 { font-size: 22px; margin: 36px 0 12px; }
p.lead { font-size: 18px; color: var(--muted); margin: 0 0 28px; max-width: 42em; }

.hero { padding: 24px 0 12px; }
.row { display: flex; flex-wrap: wrap; gap: 12px; margin: 24px 0; }
.btn {
  display: inline-block;
  padding: 10px 16px;
  border-radius: 6px;
  background: var(--accent);
  color: var(--btn-ink);
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; filter: brightness(1.08); }
.btn.ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }
.card {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
  padding: 16px 18px;
}
.card h3 { margin: 0 0 8px; font-size: 16px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }

.list { list-style: none; padding: 0; margin: 0; }
.list li { border-bottom: 1px solid var(--line); padding: 14px 0; }
.list a.title { color: var(--ink); font-weight: 650; font-size: 18px; }
.meta { font-size: 13px; color: var(--muted); margin-top: 4px; }

.prose h2:first-child { margin-top: 0; }
.prose code {
  font-family: Consolas, "Sarasa Mono SC", monospace;
  font-size: 0.92em;
  background: var(--surface);
  padding: 1px 5px;
  border-radius: 4px;
}
.prose pre {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 14px;
  overflow: auto;
  border-radius: 8px;
}
.prose pre code { background: none; padding: 0; }
.prose ul { padding-left: 1.2em; }

table.plain { width: 100%; border-collapse: collapse; font-size: 14px; }
table.plain th, table.plain td {
  text-align: left;
  padding: 10px 8px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
table.plain th { color: var(--muted); font-weight: 600; }

.note {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 12px 14px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--muted);
}

@media (max-width: 640px) {
  h1 { font-size: 28px; }
  .top { flex-direction: column; align-items: flex-start; }
}