/* openstudio: one stylesheet. Tokens first; dark mode follows [data-theme]. */
@font-face { font-family: "Spectral"; src: url("../fonts/Spectral-500.woff2") format("woff2"); font-weight: 500; font-display: swap; }
@font-face { font-family: "Spectral"; src: url("../fonts/Spectral-700.woff2") format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "Public Sans"; src: url("../fonts/PublicSans-400.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Public Sans"; src: url("../fonts/PublicSans-600.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("../fonts/IBMPlexMono-400.woff2") format("woff2"); font-weight: 400; font-display: swap; }

:root {
  --bg: #fafaf7; --surface: #ffffff; --ink: #1b1f24; --muted: #5b6470; --line: #e0e3e7;
  --accent: #0e7c86; --accent-ink: #ffffff; --accent-soft: #e2f1f2; --warn: #b4540a;
  --teal: #0e7c86; --sky: #2563a8; --amber: #b4540a; --rose: #b3395a; --violet: #6d4bb5; --lime: #4d7c0f; --coral: #c2410c;
  --radius: 10px; --gutter: 16px; --max: 1080px;
  --serif: "Spectral", Georgia, serif; --sans: "Public Sans", system-ui, sans-serif; --mono: "IBM Plex Mono", ui-monospace, monospace;
}
:root[data-theme="dark"] {
  --bg: #0f1317; --surface: #171c22; --ink: #e8ebef; --muted: #98a2ae; --line: #2a313a;
  --accent: #4fc3cc; --accent-ink: #0b1316; --accent-soft: #14282b; --warn: #f0a35e;
  --teal: #4fc3cc; --sky: #6aa8ee; --amber: #f0a35e; --rose: #ee8aa8; --violet: #b49cf0; --lime: #a3d95b; --coral: #f08a5d;
}
* { box-sizing: border-box; }
html { color-scheme: light; }
:root[data-theme="dark"] { color-scheme: dark; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 var(--sans); }
a { color: var(--accent); }
a:focus-visible, button:focus-visible, input:focus-visible, summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-ink); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; top: 8px; }

.bar { position: sticky; top: 0; z-index: 5; display: flex; align-items: center; gap: 14px; padding: 10px var(--gutter);
  background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.brand { font: 700 1.15rem var(--serif); color: var(--ink); text-decoration: none; display: inline-flex; gap: 6px; align-items: center; }
.brand__mark { color: var(--accent); }
.nav { display: flex; gap: 12px; }
.nav a { color: var(--muted); text-decoration: none; padding: 4px 2px; border-bottom: 2px solid transparent; }
.nav a:hover, .nav a[aria-current] { color: var(--ink); border-bottom-color: var(--accent); }
.bar__search { flex: 1 1 200px; max-width: 360px; margin-left: auto; }
.bar__search input { width: 100%; padding: 7px 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); font: inherit; }
.chip { display: inline-block; padding: 3px 10px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); font: 600 .78rem var(--sans); cursor: pointer; }
button.chip:hover { border-color: var(--accent); }
.chip--warn { color: var(--warn); border-color: var(--warn); }
.embed .bar, .embed .foot { display: none; }

main { max-width: var(--max); margin: 0 auto; padding: 24px var(--gutter) 48px; min-height: 70vh; outline: none; }
.hero h1 { font: 700 clamp(1.8rem, 4vw, 2.6rem)/1.15 var(--serif); margin: 0 0 6px; }
.lede { color: var(--muted); font-size: 1.1rem; max-width: 62ch; }
h2 { font: 700 1.4rem var(--serif); margin: 2rem 0 .6rem; }
h3 { font: 600 1.05rem var(--sans); margin: 1rem 0 .3rem; }
.crumb { color: var(--muted); font-size: .9rem; margin: 0 0 8px; }
.meta { color: var(--muted); font-size: .85rem; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: .75rem; color: var(--accent); font-weight: 600; margin: 0; }
.note { background: var(--accent-soft); border-left: 4px solid var(--accent); padding: 10px 14px; border-radius: 6px; }

.grid, .tiles, .list { list-style: none; padding: 0; margin: 12px 0; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); border-top: 4px solid var(--accent); }
.card--teal { border-top-color: var(--teal); } .card--sky { border-top-color: var(--sky); } .card--amber { border-top-color: var(--amber); }
.card--rose { border-top-color: var(--rose); } .card--violet { border-top-color: var(--violet); } .card--lime { border-top-color: var(--lime); }
.card--coral { border-top-color: var(--coral); }
.card__link { display: block; padding: 16px; color: inherit; text-decoration: none; height: 100%; }
.card__link:hover { background: var(--accent-soft); border-radius: var(--radius); }
.card__glyph { font: 700 1.6rem var(--serif); color: var(--accent); }
.card h2, .card h3 { margin: .2rem 0 .3rem; font-size: 1.15rem; }
.card p { margin: .2rem 0; color: var(--muted); font-size: .95rem; }
.tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.tile a { display: block; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; color: inherit; text-decoration: none; height: 100%; }
.tile a:hover { border-color: var(--accent); }
.tile .thumb { width: 100%; aspect-ratio: 16 / 10; object-fit: contain; background: var(--surface); display: block; border-bottom: 1px solid var(--line); }
.tile__t { display: block; padding: 8px 10px; font-size: .88rem; line-height: 1.35; }
.list li { padding: 4px 0; }

.lesson { max-width: 820px; }
.lesson h1 { font: 700 clamp(1.5rem, 3.4vw, 2.1rem)/1.2 var(--serif); margin: .2rem 0 .5rem; }
.fig { margin: 18px 0; }
.fig img { max-width: 100%; height: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.fig figcaption { color: var(--muted); font-size: .88rem; margin-top: 6px; }
.tex { overflow-x: auto; padding: 4px 0; }
.steps { padding-left: 1.2rem; } .steps li { margin-bottom: 1rem; }
.terms dt { font-weight: 600; margin-top: .6rem; } .terms dd { margin: 0 0 0 1rem; color: var(--muted); }
.sym { font-family: var(--serif); font-style: italic; color: var(--accent); }
.reveal { border: 1px solid var(--line); border-radius: 8px; padding: 6px 12px; margin: 6px 0; background: var(--surface); }
.reveal summary { cursor: pointer; font-weight: 600; color: var(--accent); }
.q { margin: 12px 0; padding-left: 10px; border-left: 3px solid var(--line); }
.answer { background: var(--accent-soft); padding: 8px 12px; border-radius: 6px; }
.values { border-collapse: collapse; width: 100%; font-size: .9rem; display: block; overflow-x: auto; }
.values th, .values td { border-bottom: 1px solid var(--line); padding: 6px 10px; text-align: left; }
pre { background: var(--surface); border: 1px solid var(--line); padding: 12px; overflow-x: auto; border-radius: 8px; font: .85rem var(--mono); }
.live { display: inline-block; padding: 2px 0; }
.src { margin-top: 2.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .9rem; }
.foot { max-width: var(--max); margin: 0 auto; padding: 18px var(--gutter) 32px; color: var(--muted); font-size: .85rem; display: flex; gap: 16px; flex-wrap: wrap; border-top: 1px solid var(--line); }
.noscript { padding: 16px; }

@media (max-width: 600px) { .bar { gap: 8px; } .bar__search { order: 3; flex-basis: 100%; max-width: none; } }
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; scroll-behavior: auto !important; } }