:root {
  color-scheme: light;
  --ink: #17171d;
  --muted: #5e616e;
  --brand: #2563eb;
  --soft: #eff4ff;
  --border: #d3e0f5;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Inter, Arial, sans-serif;
  line-height: 1.62;
}
main {
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 20px 56px;
}
h1 {
  margin: 0 0 8px;
  color: var(--brand);
  font-size: clamp(30px, 6vw, 44px);
  line-height: 1.1;
}
h2 {
  margin: 32px 0 10px;
  font-size: 22px;
  line-height: 1.25;
}
h3 {
  margin: 22px 0 8px;
  font-size: 18px;
  line-height: 1.3;
}
p, li { font-size: 16px; }
a { color: var(--brand); }
.muted { color: var(--muted); }
.summary, .box {
  margin: 24px 0;
  padding: 18px;
  border: 1px solid var(--border);
  background: var(--soft);
  border-radius: 10px;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 15px;
}
th, td {
  border: 1px solid var(--border);
  padding: 10px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--soft); }
ul, ol { padding-left: 22px; }
code {
  background: #f7f7f8;
  border: 1px solid #ececef;
  border-radius: 5px;
  padding: 2px 5px;
}