/* Shared by the library pages. The front page carries its own copy of these tokens inline;
   if a colour or a font changes there, change it here too. */
:root {
  --ground: #F5F6F3; --surface: #FFFFFF; --sunk: #ECEEEA;
  --ink: #16202B; --ink-2: #4A5563; --ink-3: #7D8794; --rule: #D9DEDF; --edge: #C3C7DA;
  --accent: #2447C9; --accent-ink: #FFFFFF; --accent-soft: #E4E9FA;
  --system: #0C857A; --person: #D6246E; --agent: #7B3FC4; --handoff: #CC6A14;
  --ok: #1D7C3A; --ok-soft: #E3F2E7; --warn: #9A5B00; --warn-soft: #FBEFD9;
  --font-sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-cond: "IBM Plex Sans Condensed", "Arial Narrow", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ground: #11161C; --surface: #19202A; --sunk: #0D1116;
    --ink: #E6EAEE; --ink-2: #B3BCC6; --ink-3: #87919C; --rule: #2B3440; --edge: #3C4757;
    --accent: #8FA6FF; --accent-ink: #0D1116; --accent-soft: #232D52;
    --system: #5FD3A6; --person: #EE85B2; --agent: #BD95F2; --handoff: #F0A45E;
    --ok: #6FCB8A; --ok-soft: #173222; --warn: #E7B45C; --warn-soft: #3A2C12;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--ground); color: var(--ink); font: 17px/1.6 var(--font-sans); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
[hidden] { display: none !important; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.wrap { max-width: 1200px; margin: 0 auto; padding-inline: clamp(16px, 4vw, 40px); }
h1, h2, h3 { font-family: var(--font-cond); font-weight: 600; margin: 0; text-wrap: balance; letter-spacing: -.01em; }
p { margin: 0; }
.eyebrow { font: 600 12px/1.3 var(--font-cond); letter-spacing: .14em; text-transform: uppercase; color: var(--ink-3); }
.lede { color: var(--ink-2); font-size: 20px; max-width: 58ch; }
.pill { display: inline-flex; align-items: center; font: 500 16px/1 var(--font-sans); padding: 14px 22px; border-radius: 999px; border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); text-decoration: none; white-space: nowrap; }
.pill:hover { filter: brightness(1.1); }
.pill.small { padding: 9px 16px; font-size: 14px; }
.chip { display: inline-block; font: 600 11px/1 var(--font-cond); letter-spacing: .1em; text-transform: uppercase; padding: 5px 8px; background: var(--accent-soft); color: var(--accent); }
.chip.round { border-radius: 999px; padding: 6px 10px; }
.dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 8px; flex: none; }

/* Bar and footer, as on the front page */
.bar { position: sticky; top: 0; z-index: 20; background: var(--surface); border-bottom: 1px solid var(--rule); }
.bar .wrap { display: flex; align-items: center; gap: 10px 24px; padding-block: 12px; flex-wrap: wrap; }
.brand { display: flex; align-items: baseline; gap: 10px; margin-right: auto; text-decoration: none; }
.brand b { font: 600 24px/1 var(--font-cond); letter-spacing: -.01em; }
.brand em { font-style: normal; align-self: center; margin-left: 4px; }
.nav { display: flex; gap: 22px; }
.nav a { font: 600 13px/1 var(--font-cond); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); text-decoration: none; }
.nav a:hover, .nav a[aria-current] { color: var(--ink); }
@media (max-width: 900px) { .nav a:not([aria-current]) { display: none; } }
.signin { font: 500 14px/1 var(--font-sans); color: var(--ink-2); text-decoration: none; padding: 9px 4px; }
.signin:hover { color: var(--accent); }
footer { border-top: 1px solid var(--rule); padding-block: 30px 44px; font-size: 14px; color: var(--ink-3); margin-top: clamp(48px, 7vw, 96px); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 10px 30px; justify-content: space-between; }

/* Library front page */
.lib-hero { padding-block: clamp(36px, 6vw, 72px) clamp(28px, 4vw, 48px); border-bottom: 1px solid var(--rule); }
.lib-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(24px, 4vw, 56px); align-items: center; }
.lib-hero h1 { font-size: clamp(36px, 5vw, 60px); line-height: 1.02; font-weight: 700; letter-spacing: -.025em; margin-top: 16px; }
.lib-hero .lede { margin-top: 18px; }
.search { display: block; margin-top: 28px; }
.search input { width: 100%; max-width: 520px; font: 17px var(--font-sans); color: var(--ink); background: var(--surface); border: 1px solid var(--accent); border-radius: 12px; padding: 14px 16px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.chips a { display: inline-flex; align-items: center; font-size: 14px; padding: 7px 12px; border-radius: 999px; border: 1px solid var(--rule); background: var(--surface); text-decoration: none; color: var(--ink-2); }
.chips a:hover { border-color: var(--accent); color: var(--ink); }
.mapbox { background: var(--surface); border: 1px solid var(--rule); border-radius: 14px; padding: 18px; min-width: 0; }
.mapbox canvas { display: block; width: 100%; height: clamp(300px, 34vw, 420px); }
.maptip { font-size: 14px; color: var(--ink-3); min-height: 1.6em; }
.maptip.on { color: var(--ink); font-weight: 500; }
@media (max-width: 900px) { .lib-grid { grid-template-columns: minmax(0, 1fr); } }

.shelves { padding-block: clamp(24px, 4vw, 48px) 0; }
.shelf { display: grid; grid-template-columns: 300px minmax(0, 1fr); gap: 8px clamp(20px, 4vw, 56px); padding-block: clamp(24px, 3.5vw, 40px); border-bottom: 1px solid var(--rule); scroll-margin-top: 70px; }
.shelf-h h2 { font-size: 26px; line-height: 1.15; display: flex; align-items: baseline; }
.shelf-h h2 .dot { transform: translateY(-2px); }
.shelf-h p { color: var(--ink-2); font-size: 15px; margin-top: 8px; }
.rows { display: grid; }
.row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 4px 20px; padding: 14px 0; border-top: 1px solid var(--rule); text-decoration: none; }
.rows .row:first-child { border-top: 0; padding-top: 4px; }
.row-t { font: 600 21px/1.25 var(--font-cond); }
.row:hover .row-t { color: var(--accent); }
.row-s { grid-column: 1; color: var(--ink-2); font-size: 15px; }
.row-m { grid-row: 1; grid-column: 2; font: 12px var(--font-mono); color: var(--ink-3); padding-top: 6px; white-space: nowrap; }
.none { padding-block: 40px; color: var(--ink-2); }
@media (max-width: 820px) { .shelf { grid-template-columns: minmax(0, 1fr); } }

/* An article */
.article { display: grid; grid-template-columns: minmax(0, 720px) minmax(0, 1fr); gap: clamp(24px, 5vw, 72px); padding-block: clamp(28px, 5vw, 56px) 0; }
.crumb { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--ink-3); }
.crumb a { text-decoration: none; display: inline-flex; align-items: center; }
.crumb a:hover { color: var(--ink); }
.article h1 { font-size: clamp(34px, 4.6vw, 54px); line-height: 1.04; font-weight: 700; letter-spacing: -.025em; margin-top: 18px; }
.article .lede { margin-top: 16px; }
.meta { font: 13px var(--font-mono); color: var(--ink-3); margin-top: 16px; padding-bottom: 24px; border-bottom: 1px solid var(--rule); }
.toc { position: sticky; top: 84px; align-self: start; display: grid; gap: 10px; padding-top: 8px; font-size: 15px; }
.toc a { color: var(--ink-2); text-decoration: none; }
.toc a:hover { color: var(--accent); }
@media (max-width: 1000px) { .article { grid-template-columns: minmax(0, 1fr); } .toc { display: none; } }

.prose { font-size: 18px; line-height: 1.7; padding-top: 28px; }
.prose > * + * { margin-top: 1.1em; }
.prose h2 { font-size: 30px; line-height: 1.15; margin-top: 1.8em; scroll-margin-top: 84px; }
.prose h3 { font-size: 22px; line-height: 1.25; margin-top: 1.5em; }
.prose a { color: var(--accent); text-underline-offset: 3px; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li + li { margin-top: .4em; }
.prose li::marker { color: var(--accent); font-weight: 600; }
.prose strong { font-weight: 600; }
.prose code { font: .88em var(--font-mono); background: var(--sunk); padding: 2px 6px; border-radius: 4px; }
.prose blockquote { margin-inline: 0; padding-left: 20px; border-left: 3px solid var(--accent); font-size: 21px; line-height: 1.5; color: var(--ink); }
.prose hr { border: 0; border-top: 1px solid var(--rule); margin-block: 2em; }
.prose table { width: 100%; border-collapse: collapse; font-size: 16px; display: block; overflow-x: auto; }
.prose th, .prose td { text-align: left; padding: 10px 14px 10px 0; border-bottom: 1px solid var(--rule); vertical-align: top; }
.prose th { font: 600 13px var(--font-cond); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); }
figure { margin: 1.8em 0; }
figure img { display: block; width: 100%; height: auto; border: 1px solid var(--rule); border-radius: 12px; background: var(--surface); box-shadow: 0 14px 40px rgba(22, 32, 43, .08); }
figcaption { font-size: 14px; color: var(--ink-3); margin-top: 10px; }
.video { position: relative; aspect-ratio: 16 / 9; margin-block: 1.8em; border-radius: 12px; overflow: hidden; background: var(--ink); border: 1px solid var(--rule); }
.video button { all: unset; cursor: pointer; position: absolute; inset: 0; display: grid; place-items: center; }
.video button img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.video .poster { color: #fff; font: 600 22px var(--font-cond); padding: 0 24px 96px; text-align: center; }
.video .play { position: relative; width: 76px; height: 76px; border-radius: 50%; background: var(--accent); box-shadow: 0 8px 30px rgba(0, 0, 0, .35); }
.video .poster + .play { position: absolute; }
.video .play::after { content: ""; position: absolute; left: 30px; top: 23px; border-left: 24px solid #fff; border-top: 15px solid transparent; border-bottom: 15px solid transparent; }
.video button:focus-visible .play { outline: 3px solid #fff; outline-offset: 3px; }
.video iframe, .video video { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.callout { border-radius: 12px; padding: 16px 20px; background: var(--accent-soft); font-size: 17px; }
.callout > * + * { margin-top: .5em; }
.callout-h { font: 600 12px/1.3 var(--font-cond); letter-spacing: .14em; text-transform: uppercase; color: var(--accent); }
.callout.tip { background: var(--ok-soft); } .callout.tip .callout-h { color: var(--ok); }
.callout.warning { background: var(--warn-soft); } .callout.warning .callout-h { color: var(--warn); }

.related { margin-top: 56px; padding-top: 22px; border-top: 2px solid var(--ink); }
.related .row:first-of-type { border-top: 0; }
.cta { margin-top: 48px; background: var(--surface); border: 1px solid var(--rule); border-radius: 16px; padding: clamp(20px, 3vw, 32px); display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px 24px; }
.cta h2 { font-size: 28px; }
.cta p { color: var(--ink-2); margin-top: 4px; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }