*, *::before, *::after { box-sizing: border-box; }
:root {
  --ink: #1b1f26; --ink-2: #475062; --line: #e3e7ef; --bg: #ffffff; --bg-soft: #f7f9fc;
  --accent: #1668c1; --accent-soft: #eaf2fd;
}
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px; line-height: 1.8;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }
header.site { border-bottom: 1px solid var(--line); background: var(--bg-soft); }
header.site .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px; padding: 14px 20px; }
.brand { font-weight: 600; color: var(--ink); text-decoration: none; letter-spacing: .01em; }
header nav { display: flex; flex-wrap: wrap; gap: 6px 16px; margin-left: auto; }
header nav a { color: var(--ink-2); text-decoration: none; font-size: 15px; }
header nav a:hover, header nav a.cur { color: var(--accent); }
main { padding: 40px 20px 56px; }
h1 { font-size: 30px; line-height: 1.35; margin: 0 0 18px; letter-spacing: .01em; text-wrap: balance; }
h2 { font-size: 21px; margin: 36px 0 10px; }
p, li, dd { color: var(--ink); }
p { margin: 0 0 16px; }
p.lead { font-size: 17px; color: var(--ink-2); border-left: 3px solid var(--accent); padding-left: 14px; }
a { color: var(--accent); text-underline-offset: 3px; }
ul, ol { padding-left: 22px; margin: 0 0 18px; }
li { margin-bottom: 8px; }
.cards { display: grid; gap: 14px; margin: 26px 0 8px; }
.card { display: block; border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; text-decoration: none; background: var(--bg); transition: border-color .15s ease, background .15s ease; }
.card:hover { border-color: var(--accent); background: var(--accent-soft); }
.card h2 { margin: 0 0 6px; font-size: 18px; color: var(--ink); text-wrap: balance; }
.card p { margin: 0; color: var(--ink-2); font-size: 15px; }
dt { font-weight: 600; margin-top: 18px; }
dd { margin: 4px 0 0; color: var(--ink-2); }
footer.site { border-top: 1px solid var(--line); background: var(--bg-soft); }
footer.site .wrap { padding: 22px 20px 34px; }
footer.site p { font-size: 14px; color: var(--ink-2); margin: 0 0 8px; }
.muted { color: #6b7385; }
table { width: 100%; border-collapse: collapse; margin: 0 0 18px; font-size: 15px; }
th, td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: var(--bg-soft); font-weight: 600; }
pre { background: var(--bg-soft); border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; overflow-x: auto; font-size: 14px; line-height: 1.6; margin: 0 0 16px; }
pre code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
@media (min-width: 720px) { .cards { grid-template-columns: repeat(3, 1fr); align-items: stretch; } h1 { font-size: 34px; } }