:root {
  --bg: #f6f7f9; --surface: #ffffff; --text: #15181d; --muted: #5b6472; --border: #d9dee6;
  --accent: #0b5fff; --accent-ink: #ffffff; --accent-soft: #e8efff;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 8px 24px rgba(16, 24, 40, 0.06);
  --radius: 12px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Inter, Helvetica, Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1216; --surface: #171b21; --text: #e7eaee; --muted: #9aa4b2; --border: #2a313b;
    --accent: #6ea0ff; --accent-ink: #0b1020; --accent-soft: #1b2638;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.35);
  }
}
:root[data-theme="dark"] {
  --bg: #0f1216; --surface: #171b21; --text: #e7eaee; --muted: #9aa4b2; --border: #2a313b;
  --accent: #6ea0ff; --accent-ink: #0b1020; --accent-soft: #1b2638;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.35);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; font-family: var(--font); font-size: 16px; line-height: 1.55; color: var(--text); background: var(--bg); }
a { color: var(--accent); }
h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5rem; }
h1 { font-size: clamp(1.7rem, 4vw, 2.4rem); }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.05rem; }
p { margin: 0 0 0.9rem; }
.muted { color: var(--muted); }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }
.site-header { border-bottom: 1px solid var(--border); background: var(--surface); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 60px; flex-wrap: wrap; }
.brand { font-weight: 700; text-decoration: none; color: var(--text); font-size: 1.1rem; letter-spacing: -0.01em; }
.brand span { color: var(--accent); }
.nav { display: flex; align-items: center; gap: 4px 16px; flex-wrap: wrap; }
.nav a { color: var(--muted); text-decoration: none; font-size: 0.95rem; }
.nav a[aria-current="page"] { color: var(--text); font-weight: 600; }
.theme-toggle { border: 1px solid var(--border); background: var(--surface); color: var(--text); border-radius: 999px; padding: 4px 10px; font: inherit; font-size: 0.85rem; cursor: pointer; }
main { padding: 32px 0 48px; }
.hero { padding: 24px 16px 8px; }
.hero p { font-size: 1.1rem; max-width: 60ch; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; margin: 24px 0; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 8px; }
.card .for { font-size: 0.85rem; color: var(--muted); }
.card .platform { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
.card a.cta { margin-top: auto; display: inline-block; text-decoration: none; font-weight: 600; }
.card a.cta[aria-disabled="true"] { color: var(--muted); font-weight: 500; cursor: default; }
.principles { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin: 24px 0; }
.principles ul { margin: 8px 0 0; padding-left: 20px; }
.prose { max-width: 72ch; }
.prose h2 { margin-top: 2rem; padding-top: 1rem; border-top: 1px solid var(--border); }
.prose h3 { margin-top: 1.25rem; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin-bottom: 0.35rem; }
.prose table { border-collapse: collapse; width: 100%; font-size: 0.95rem; margin: 8px 0 16px; }
.prose th, .prose td { text-align: left; border-bottom: 1px solid var(--border); padding: 8px 6px; vertical-align: top; }
.toc { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 18px; margin: 16px 0 24px; }
.toc ol { margin: 6px 0 0; padding-left: 20px; columns: 2; column-gap: 24px; }
.toc li { break-inside: avoid; }
.note { background: var(--accent-soft); border-left: 4px solid var(--accent); padding: 10px 14px; border-radius: 6px; margin: 12px 0 18px; }
.placeholder { background: #fff3bf; color: #4a3b00; padding: 0 4px; border-radius: 3px; }
:root[data-theme="dark"] .placeholder { background: #4a3b00; color: #ffe08a; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .placeholder { background: #4a3b00; color: #ffe08a; } }
.site-footer { border-top: 1px solid var(--border); background: var(--surface); padding: 20px 0 28px; font-size: 0.9rem; color: var(--muted); }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; }
.site-footer a { color: var(--muted); }
@media (max-width: 480px) { .toc ol { columns: 1; } .nav a { font-size: 0.9rem; } }