:root {
  --ink: #1a2332;
  --muted: #5a6a7e;
  --line: #e5e9f0;
  --bg: #ffffff;
  --soft: #f6f8fb;
  --accent: #2456e0;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.7; font-size: 17px;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }
.site-header { border-bottom: 1px solid var(--line); background: var(--bg); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.logo { font-weight: 800; font-size: 19px; color: var(--ink); text-decoration: none; }
.logo span { color: var(--accent); }
.site-header nav a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 15px; }
.site-header nav a:hover { color: var(--accent); }
main { padding: 36px 20px 60px; }
.updated { color: var(--muted); font-size: 14px; margin-bottom: 8px; }
h1 { font-size: 34px; line-height: 1.25; margin-bottom: 14px; letter-spacing: -0.02em; }
h2 { font-size: 24px; margin: 36px 0 12px; letter-spacing: -0.01em; }
h3 { font-size: 18px; margin: 22px 0 8px; }
p { margin-bottom: 14px; }
.lede { font-size: 19px; color: #2c3a4f; }
ul { margin: 0 0 14px 22px; }
li { margin-bottom: 8px; }
code { background: var(--soft); padding: 2px 6px; border-radius: 4px; font-size: 0.9em; }
a { color: var(--accent); }
.toc { background: var(--soft); border: 1px solid var(--line); border-radius: 10px; padding: 16px 20px; margin: 22px 0; display: flex; flex-direction: column; }
.toc strong { margin-bottom: 6px; font-size: 14px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }
.toc a { text-decoration: none; padding: 2px 0; }
.table-wrap { overflow-x: auto; margin: 16px 0; }
table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; }
th { background: var(--soft); }
.related h2 { margin-top: 48px; }
.card { display: block; border: 1px solid var(--line); border-radius: 10px; padding: 14px 18px; margin-bottom: 10px; text-decoration: none; color: var(--ink); }
.card:hover { border-color: var(--accent); }
.card span { display: block; font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--accent); margin-bottom: 2px; }
.site-footer { border-top: 1px solid var(--line); padding: 24px 0; color: var(--muted); font-size: 14px; }
.note { background: #fff8e8; border: 1px solid #f0dfb2; border-radius: 8px; padding: 12px 16px; margin: 16px 0; font-size: 15px; }
@media (max-width: 600px) {
  h1 { font-size: 27px; }
  .site-header nav a { margin-left: 10px; font-size: 13px; }
}