:root {
  color-scheme: light;
  --bg: #f7f8fb;
  --paper: #ffffff;
  --text: #172033;
  --muted: #667085;
  --line: #e6eaf2;
  --accent: #2563eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 12% 0%, rgba(37, 99, 235, 0.09), transparent 32rem),
    linear-gradient(180deg, #fbfcff 0%, var(--bg) 100%);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
}

.page {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0 64px;
}

.brand {
  color: var(--muted);
  font-size: 14px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.paper {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: 0 24px 70px rgba(23, 32, 51, 0.08);
  padding: clamp(28px, 5vw, 56px);
}

h1 {
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1.15;
  margin: 0 0 24px;
  letter-spacing: -0.04em;
}

h2 {
  border-top: 1px solid var(--line);
  font-size: 22px;
  margin: 36px 0 12px;
  padding-top: 28px;
}

h3 {
  font-size: 18px;
  margin: 28px 0 8px;
}

p {
  margin: 12px 0;
}

ul {
  padding-left: 1.3em;
}

li {
  margin: 6px 0;
}

code {
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  color: #0f172a;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  padding: 0.12em 0.4em;
}

a {
  color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

.footer {
  color: var(--muted);
  font-size: 14px;
  margin-top: 24px;
  text-align: center;
}

@media (max-width: 640px) {
  .page {
    width: min(100% - 20px, 920px);
    padding: 20px 0 36px;
  }

  .paper {
    border-radius: 22px;
  }
}