/* 5′ to 3′ explained: show-notes site (tools/site/build.py) */
:root { --bg: #ffffff; --surface: #f6f8fa; --ink: #1f2328; --muted: #59636e; --rule: #d1d9e0; --accent: #8250df; --gold: #9a6700;
  --at: #d9620f; --gc: #2459c7; color-scheme: light dark; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --bg: #0d1117; --surface: #161b22; --ink: #e6edf3;
  --muted: #9198a1; --rule: #30363d; --accent: #b083f0; --gold: #f2c94c; --at: #ffb25c; --gc: #7fb2ff; } }
:root[data-theme="dark"] { --bg: #0d1117; --surface: #161b22; --ink: #e6edf3; --muted: #9198a1; --rule: #30363d; --accent: #b083f0; --gold: #f2c94c; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Helvetica Neue", Helvetica, Arial, sans-serif; }
a { color: var(--accent); }
.top { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 16px; border-bottom: 1px solid var(--rule); }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--ink); text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 50%; }
.yt { font-size: 15px; }
main { max-width: 780px; margin: 0 auto; padding: 24px 16px 48px; }
h1 { font-size: clamp(28px, 6vw, 40px); line-height: 1.15; margin: 4px 0 16px; }
h2 { margin: 40px 0 8px; font-size: 24px; padding-top: 8px; border-top: 1px solid var(--rule); }
h3 { margin: 24px 0 6px; font-size: 17px; color: var(--muted); }
.kicker { margin: 0; color: var(--gold); font-weight: 700; text-transform: uppercase; letter-spacing: .08em; font-size: 13px; }
.lede { font-size: 19px; }
.note, .soon { color: var(--muted); font-size: 15px; }
.hero, .frame { width: 100%; border-radius: 10px; display: block; border: 1px solid var(--rule); }
.btn { display: inline-block; background: var(--accent); color: #fff; font-weight: 700; padding: 10px 18px; border-radius: 10px; text-decoration: none; }
.toc { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }
.toc a { background: var(--surface); border: 1px solid var(--rule); border-radius: 999px; padding: 4px 12px; font-size: 15px; text-decoration: none; }
.vocab div { padding: 10px 0; border-bottom: 1px solid var(--rule); }
.vocab dt { font-weight: 700; }
.vocab dd { margin: 2px 0 0; }
.t { font: 600 13px/1 ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--muted); margin-left: 6px; text-decoration: none; white-space: nowrap; }
a.t { color: var(--accent); }
.qs li { margin: 0 0 14px; }
.qs p { margin: 0 0 4px; }
.qs summary { cursor: pointer; color: var(--accent); font-size: 15px; }
.qs details p { background: var(--surface); padding: 8px 12px; border-radius: 8px; margin-top: 6px; }
.plain, .refs { padding-left: 18px; }
.refs li { margin-bottom: 8px; font-size: 15px; overflow-wrap: anywhere; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 320px), 1fr)); gap: 16px; }
.card { display: flex; flex-direction: column; gap: 6px; padding: 0 0 12px; background: var(--surface); border: 1px solid var(--rule); border-radius: 12px; overflow: hidden; text-decoration: none; color: var(--ink); }
.card img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.card b, .card span { padding: 0 12px; }
.card span { color: var(--muted); font-size: 15px; }
footer { text-align: center; color: var(--muted); font-size: 14px; padding: 24px 16px; border-top: 1px solid var(--rule); }