:root {
  --bg: #ffffff;
  --fg: #0f172a;
  --muted: #475569;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --card-bg: #f8fafc;
  --max: 760px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  font-size: 16px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

.site-header {
  max-width: var(--max);
  margin: 0 auto;
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border);
}

.brand { color: var(--fg); font-weight: 700; font-size: 20px; letter-spacing: -0.01em; }
.brand:hover { text-decoration: none; color: var(--fg); }

.site-nav { display: flex; gap: 20px; flex-wrap: wrap; }
.site-nav a { color: var(--muted); font-size: 15px; }
.site-nav a:hover { color: var(--accent); }

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 32px 24px 64px;
}

.hero h1 {
  font-size: 36px;
  line-height: 1.15;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
.hero .lede { color: var(--muted); font-size: 17px; margin: 0 0 32px; }

h1, h2, h3 { color: var(--fg); }
h2 { font-size: 20px; margin: 32px 0 12px; letter-spacing: -0.01em; }
h3 { font-size: 17px; margin: 24px 0 8px; }

.updated { color: var(--muted); font-size: 13px; margin-bottom: 32px; }

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px 28px;
  margin-top: 24px;
}

.card h2:first-child { margin-top: 0; }

.kv { display: grid; grid-template-columns: 160px 1fr; gap: 8px 24px; margin: 0; }
.kv dt { color: var(--muted); font-weight: 500; }
.kv dd { margin: 0; color: var(--fg); }

details {
  border-top: 1px solid var(--border);
  padding: 14px 0;
}
details:first-of-type { border-top: none; padding-top: 6px; }
summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--fg);
  list-style: none;
  padding: 4px 0;
  position: relative;
  padding-right: 24px;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  font-size: 18px;
  font-weight: 400;
}
details[open] summary::after { content: "−"; }
details p { margin: 12px 0 4px; color: var(--muted); }

.link-list { list-style: none; padding: 0; margin: 0; }
.link-list li { padding: 8px 0; border-top: 1px solid var(--border); }
.link-list li:first-child { border-top: none; }

ol, ul { padding-left: 20px; }
li { margin: 6px 0; }

.step-list { list-style: none; padding: 0; counter-reset: step; }
.step-list li {
  counter-increment: step;
  padding: 14px 0 14px 48px;
  position: relative;
  border-top: 1px solid var(--border);
}
.step-list li:first-child { border-top: none; }
.step-list li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 14px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.callout {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  padding: 14px 18px;
  margin: 20px 0;
  color: #1e3a8a;
  font-size: 15px;
}

.site-footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 32px 24px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.site-footer p { margin: 0; }

@media (max-width: 520px) {
  .kv { grid-template-columns: 1fr; gap: 2px; }
  .kv dt { margin-top: 8px; }
  .hero h1 { font-size: 30px; }
}