:root {
  color-scheme: light;
  --ink: #182033;
  --muted: #526078;
  --paper: #ffffff;
  --surface: #f4f7fb;
  --line: #dbe3ef;
  --accent: #185abc;
  --accent-soft: #e8f0fe;
  --warning: #fff7e0;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--surface);
  font-family: Inter, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.65;
}

a { color: var(--accent); }

.shell {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

header, main, footer {
  background: var(--paper);
  border: 1px solid var(--line);
}

header {
  padding: 34px 42px 28px;
  border-radius: 16px 16px 0 0;
}

main { padding: 12px 42px 34px; }

footer {
  padding: 20px 42px;
  border-radius: 0 0 16px 16px;
  color: var(--muted);
  font-size: .92rem;
}

h1, h2, h3 { line-height: 1.25; }
h1 { margin: 0 0 8px; font-size: clamp(2rem, 5vw, 3rem); letter-spacing: -.03em; }
h2 { margin-top: 38px; padding-top: 4px; }
h3 { margin-bottom: 6px; }
p, li { max-width: 72ch; }

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: .83rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.lead { color: var(--muted); font-size: 1.1rem; }

.notice {
  margin: 26px 0;
  padding: 16px 18px;
  background: var(--warning);
  border-left: 4px solid #d49b00;
}

.lang {
  padding: 26px 0 8px;
  border-top: 1px solid var(--line);
}

.lang:first-child { border-top: 0; padding-top: 8px; }

.tag {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 8px;
  color: #174ea6;
  background: var(--accent-soft);
  border-radius: 999px;
  font-size: .76rem;
  font-weight: 700;
  vertical-align: middle;
}

code {
  padding: .08em .28em;
  background: #eef2f7;
  border-radius: 4px;
  font-family: ui-monospace, Consolas, monospace;
  font-size: .9em;
}

@media (max-width: 600px) {
  .shell { width: min(100% - 20px, 900px); margin: 10px auto; }
  header, main, footer { padding-left: 22px; padding-right: 22px; }
  header { border-radius: 12px 12px 0 0; }
  footer { border-radius: 0 0 12px 12px; }
}