:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #536171;
  --line: #cbd5df;
  --surface: #ffffff;
  --background: #edf2f4;
  --blue: #005f73;
  --teal: #0a9396;
  --gold: #ca6702;
  --navy: #233b59;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

main {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 56px;
}

header {
  border-bottom: 4px solid var(--teal);
  padding: 0 0 22px;
}

h1, h2, h3 { line-height: 1.25; font-weight: 700; }
h1 { margin: 0; font-size: 32px; color: var(--navy); }
h2 { margin: 0 0 12px; font-size: 23px; color: var(--blue); }
h3 { margin: 18px 0 8px; font-size: 18px; }
p { margin: 8px 0; }

.lede { color: var(--muted); max-width: 850px; }
.tag {
  display: inline-block;
  color: #fff;
  background: var(--blue);
  font-size: 13px;
  line-height: 1;
  padding: 6px 9px;
  margin-bottom: 12px;
}

.quick-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.quick-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--blue);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.25;
  text-decoration: none;
}

.quick-nav a:hover { background: #dce8ed; color: var(--navy); }

section { margin-top: 28px; }
.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}
.card, .diagram {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 18px;
  border-radius: 6px;
}
.card h2 { font-size: 19px; }
.diagram { position: relative; overflow-x: auto; }
.diagram.mermaid svg {
  width: 100% !important;
  max-width: none !important;
  height: auto !important;
}

.diagram-zoom, .diagram-zoom-close {
  position: absolute;
  top: 12px;
  right: 12px;
  min-height: 34px;
  padding: 6px 10px;
  border: 1px solid var(--blue);
  border-radius: 6px;
  background: var(--surface);
  color: var(--blue);
  font: inherit;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
}

.diagram-zoom:hover, .diagram-zoom-close:hover { background: #dce8ed; }
.diagram-zoom-close { display: none; z-index: 1; }
.diagram-backdrop { display: none; }
.diagram-backdrop.active { display: block; position: fixed; top: 0; right: 0; bottom: 0; left: 0; z-index: 450; background: rgba(0, 0, 0, .7); }
body.diagram-expanded-open { overflow: hidden; }
.diagram.diagram-expanded {
  position: fixed;
  top: 16px;
  right: 16px;
  bottom: 16px;
  left: 16px;
  z-index: 500;
  margin: 0;
  max-width: none;
  padding: 60px 24px 24px;
  overflow: auto;
  box-shadow: 0 10px 30px rgba(0, 0, 0, .35);
}
.diagram.diagram-expanded .diagram-zoom { display: none; }
.diagram.diagram-expanded .diagram-zoom-close { display: inline-flex; align-items: center; }
.diagram.diagram-expanded svg { min-width: 1280px; }

a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--gold); }

table { border-collapse: collapse; width: 100%; background: var(--surface); }
th, td { border: 1px solid var(--line); padding: 10px; text-align: left; vertical-align: top; }
th { background: #dce8ed; color: #18354d; }
code { font-family: Consolas, monospace; font-size: .9em; color: #7c2d12; }

.notice {
  border-left: 5px solid var(--gold);
  padding: 10px 14px;
  background: #fff8e7;
}

footer { color: var(--muted); font-size: 14px; margin-top: 40px; }

@media (max-width: 780px) {
  main { width: min(100% - 24px, 1180px); padding-top: 20px; }
  h1 { font-size: 26px; }
  .grid { grid-template-columns: 1fr; }
  th, td { min-width: 135px; }
  .quick-nav { flex-wrap: nowrap; overflow-x: auto; }
  .quick-nav a { flex: 0 0 auto; }
  .diagram.mermaid { min-width: 760px; }
  .diagram.diagram-expanded { top: 8px; right: 8px; bottom: 8px; left: 8px; padding: 56px 12px 12px; }
  .diagram.diagram-expanded svg { min-width: 1100px; }
}