:root {
  --bg: #ffffff;
  --surface: #f6faf8;
  --text: #0f172a;
  --muted: #475569;
  --border: #dde7e2;
  --brand: #0d6e4f;
  --brand-light: #16a34a;
  --brand-ink: #ffffff;
  --tint: #e6f7f1;
  --radius: 16px;
  --max: 1080px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    --bg: #0b1210;
    --surface: #111b17;
    --text: #e8f1ed;
    --muted: #9fb3aa;
    --border: #22332c;
    --brand: #34d399;
    --brand-light: #10b981;
    --brand-ink: #04281c;
    --tint: #12251e;
  }
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) .brand img,
  :root:not([data-theme='light']) .hero-art img,
  :root:not([data-theme='light']) footer.site img { background: #fff; border-radius: 12px; padding: 4px 8px; }
  :root:not([data-theme='light']) .hero-art img { padding: 16px; border-radius: 28px; }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; }
a { color: var(--brand); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--brand-light); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--brand); color: var(--brand-ink); padding: 8px 14px; border-radius: 8px; z-index: 10; }
.skip:focus { left: 8px; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }

header.site { border-bottom: 1px solid var(--border); background: var(--bg); position: sticky; top: 0; z-index: 5; }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 64px; }
.brand img { display: block; height: 34px; width: auto; }
nav.primary { display: flex; flex-wrap: wrap; gap: 4px 20px; font-size: 15px; }
nav.primary a { color: var(--text); text-decoration: none; padding: 6px 0; }
nav.primary a:hover, nav.primary a[aria-current='page'] { color: var(--brand); }

.btn { display: inline-block; background: var(--brand); color: var(--brand-ink); padding: 12px 22px; border-radius: 999px; font-weight: 700; text-decoration: none; }
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn.ghost { background: transparent; color: var(--brand); border: 2px solid var(--brand); }
.badge { display: inline-block; font-size: 13px; font-weight: 700; padding: 4px 12px; border-radius: 999px; background: var(--tint); color: var(--brand); }

.hero { padding: 72px 0 56px; background: linear-gradient(180deg, var(--tint), var(--bg)); }
.hero .wrap { display: grid; gap: 40px; align-items: center; grid-template-columns: 1.2fr 1fr; }
.hero h1 { font-size: clamp(2rem, 5vw, 3.2rem); line-height: 1.1; margin: 14px 0; letter-spacing: -0.02em; }
.hero p.lead { font-size: 1.15rem; color: var(--muted); max-width: 34em; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.hero-art { display: flex; justify-content: center; }
.hero-art img { width: min(100%, 360px); }

section { padding: 56px 0; }
section.alt { background: var(--surface); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2rem); letter-spacing: -0.01em; margin: 0 0 12px; line-height: 1.2; }
.sub { color: var(--muted); max-width: 44em; margin: 0 0 32px; }
.grid { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; }
section.alt .card { background: var(--bg); }
.card h3 { margin: 0 0 6px; font-size: 1.05rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.95rem; }
.ticks { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.ticks li { padding-left: 28px; position: relative; }
.ticks li::before { content: '✓'; position: absolute; left: 0; color: var(--brand); font-weight: 800; }
.note { font-size: 0.9rem; color: var(--muted); }

.doc { padding: 48px 0 72px; }
.doc .wrap { max-width: 760px; }
.doc h1 { font-size: clamp(1.9rem, 4vw, 2.5rem); line-height: 1.15; margin: 0 0 8px; letter-spacing: -0.02em; }
.doc .meta { color: var(--muted); font-size: 0.95rem; margin-bottom: 28px; }
.doc h2 { font-size: 1.35rem; margin: 40px 0 10px; }
.doc h3 { font-size: 1.05rem; margin: 24px 0 6px; }
.doc ul, .doc ol { padding-left: 22px; }
.doc li { margin: 4px 0; }
.doc table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 0.95rem; }
.doc th, .doc td { text-align: left; vertical-align: top; padding: 10px 12px; border: 1px solid var(--border); }
.doc th { background: var(--surface); }
.callout { background: var(--tint); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 20px; margin: 20px 0; }
.toc { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 22px; margin-bottom: 8px; font-size: 0.95rem; }
.toc ol { columns: 2; column-gap: 28px; margin: 6px 0; }

footer.site { border-top: 1px solid var(--border); background: var(--surface); padding: 36px 0; font-size: 0.92rem; color: var(--muted); }
footer.site .wrap { display: grid; gap: 24px; grid-template-columns: 1.4fr 1fr 1fr; }
footer.site h2 { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text); margin: 0 0 8px; }
footer.site ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
footer.site a { color: var(--muted); }
footer.site a:hover { color: var(--brand); }
footer.site .legal { grid-column: 1 / -1; border-top: 1px solid var(--border); padding-top: 16px; }

@media (max-width: 760px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .hero-art { order: -1; }
  .hero-art img { width: 160px; }
  footer.site .wrap { grid-template-columns: 1fr; }
  .toc ol { columns: 1; }
  header.site .wrap { flex-wrap: wrap; padding-top: 10px; padding-bottom: 10px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }