/* Site chrome shared by every page: the nav bar and its mobile menu.
 *
 * The three pages that use it sit on different grounds — the landing and
 * project pages on paper white, the docs on the warmer #F3F1E9 — so every
 * colour here comes from a token the page sets on :root. Structure (sizes,
 * spacing, typography, fixed positioning) is shared; only colour and the brand
 * shadow vary. Load this before the page's own sheet.
 *
 * Tokens, with the defaults below covering the paper-white pages:
 *   --nav-bg          nav backdrop; defaults to the hero scrim, which a page's
 *                     --fade0/1/2 re-tint. The docs set a flat fill instead.
 *   --nav-ink         active / hover text
 *   --nav-muted       idle text
 *   --nav-hover-bg    hover pill
 *   --nav-dot         active marker
 *   --brand-ink       colour of the gear mark's hard shadow
 *   --menu-bg         mobile overlay fill
 *   --menu-line       mobile overlay row divider
 *
 * The burger and the overlay are always in the DOM but hidden; a page opts
 * into them by unhiding `nav .right button.burger` in its own media query.
 */

:root {
  --site-nav-height: 56px;
  /* Left edge of the nav brand and hero copy; past 2036px it centres an 1800px stage. */
  --page-inset: max(28px, 6.4vw, 50vw - 900px);
  --nav-bg: linear-gradient(to bottom, var(--fade0, rgba(250,250,248,0.78)) 0%, var(--fade1, rgba(250,250,248,0.40)) 55%, var(--fade2, rgba(250,250,248,0)) 100%);
  --nav-ink: #182B49;
  --nav-muted: #6B7080;
  --nav-hover-bg: #F0F0EE;
  --nav-dot: var(--accent, #00629B);
  --brand-ink: rgba(21, 23, 31, 0.35);
  --menu-bg: #FAFAF8;
  --menu-line: rgba(21, 23, 31, 0.14);
}

html { scroll-padding-top: calc(var(--site-nav-height) + 12px); }
* { box-sizing: border-box; }
a { color: inherit; text-decoration: none; }

/* ---------- nav ---------- */
/* The product navigation stays above the page and chapter controls. */
nav {
  height: var(--site-nav-height);
  display: flex; align-items: center;
  /* the right gutter mirrors the left, less the icon button's 8px of padding */
  padding: 0 calc(var(--page-inset) - 8px) 0 var(--page-inset); font-size: 13px; z-index: 100;
  background: var(--nav-bg);
}
.site-nav {
  position: fixed; top: 0; left: 0; right: 0;
  transition: box-shadow 180ms ease;
}
.site-nav.is-scrolled, .site-nav:has(+ .menu.is-open) {
  background: color-mix(in srgb, var(--band, #FAFAF8) 94%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(24,43,73,.12);
}
@media (prefers-reduced-motion: reduce) { .site-nav { transition: none; } }
/* ---------- copy affordance ---------- */
/* Every copy button on the site is the same two spans: `.t` is the resting
   label and `.o` the acknowledgement, which appears beside it rather than
   replacing it. An icon-only button has no room for both, so it opts into
   the swap with .copy--swap. */
.o { display: none; }
.is-copied .o { display: inline; }
.copy--swap.is-copied .t, .copy--swap.is-copied .p { display: none; }

nav .brand { display: flex; align-items: center; gap: 14px; margin-right: 36px; }
nav .brand img { width: 32px; height: 32px; display: block; filter: drop-shadow(2.5px 2.5px 0 var(--brand-ink)); }
nav .brand .wordmark {
  font-family: 'JetBrains Mono', monospace;
  font-weight: 500; font-size: 17px; letter-spacing: 0.30em; text-transform: uppercase;
  color: var(--nav-ink); line-height: 1;
  /* tracking leaves a trailing space after the last letter; pull it back so the
     wordmark's optical right edge lands where it did before */
  margin-right: -0.30em;
  transform: translateY(-0.5px);
}
/* Eleven tracked capitals scan as one run, so a hair over the tracking is
   enough to hint at the org half — no second colour needed. */
nav .brand .wordmark .o { display: inline-block; margin-right: 0.10em; }
nav .links { position: absolute; left: 50%; transform: translateX(-50%); display: flex; gap: 4px; }
nav .links a {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 10px; border-radius: 6px; color: var(--nav-muted);
  font-family: 'JetBrains Mono', monospace; font-size: 14px;
}
nav .links a:hover { background: var(--nav-hover-bg); color: var(--nav-ink); }
nav .links a.is-active { color: var(--nav-ink); }
nav .links a .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--nav-dot); }
nav .right { margin-left: auto; display: flex; align-items: center; gap: 4px; }
nav .right a, nav .right button {
  width: 38px; height: 38px; display: inline-flex; align-items: center; justify-content: center;
  border-radius: 6px; color: var(--nav-muted); cursor: pointer; border: none; background: transparent;
}
nav .right a:hover, nav .right button:hover { color: var(--nav-ink); background: var(--nav-hover-bg); }
nav .right a svg, nav .right button svg { width: 22px; height: 22px; }
nav .right button.burger { display: none; }

/* The link row is centred by absolute positioning, so on a viewport that is
   narrow but still too wide to hide it, it rides over the wordmark. Below that
   width the links simply flow after the brand instead. */
@media (max-width: 1080px) {
  nav .links { position: static; transform: none; }
}

/* On a narrow phone the tracked wordmark eats the whole bar; the mark alone
   still reads as the brand, so drop the letters and keep the logo. */
@media (max-width: 560px) {
  nav .brand .wordmark { display: none; }
  nav .brand { margin-right: 16px; }
}

/* ---------- mobile menu overlay ---------- */
.menu {
  display: none; position: fixed; top: var(--site-nav-height); left: 0; right: 0; bottom: 0;
  z-index: 99; background: var(--menu-bg); padding: 18px 24px;
  flex-direction: column; gap: 2px;
}
.menu.is-open { display: flex; }
.menu a {
  font-family: 'JetBrains Mono', monospace; font-size: 17px;
  padding: 14px 4px; border-bottom: 1px solid var(--menu-line); color: var(--nav-ink);
}

/* ---------- hero clips ---------- */
/* A clip sits over a tracked still of its own first frame. It fades in once it
   can actually play, so the handover reads as the image coming to life rather
   than a snap; if it never loads, site.js hides it and the still just stays. */
video[data-fallback] { opacity: 0; transition: opacity 420ms ease; }
video[data-fallback].is-ready { opacity: 1; }

/* ---------- tab tray ---------- */
/* A docs page's `=== "uv"` tray, styled like the project pages' task switcher:
   the active cell takes the site's offset shadow, the .chip / .cta / .ghost idiom. */
.tabs {
  display: grid; gap: 4px; padding: 8px;
  border-bottom: 1px solid #EDEDEB; background: #F3F3F0;
}
/* A docs tray holds two or three labels; `uv` on its own is too small a target,
   so a cell is at least a comfortable click wide and grows with its label. */
.tabs {
  grid-auto-flow: column; grid-auto-columns: minmax(112px, max-content);
  justify-content: start;
}
.tabs button {
  min-width: 0; padding: 11px 10px; border: 0; border-radius: 9px; background: transparent;
  color: #777C89; cursor: pointer; font-family: 'JetBrains Mono', monospace;
  font-size: 12.5px; line-height: 1.25;
  transition: color 120ms ease, transform 120ms ease, box-shadow 120ms ease;
}
.tabs button:hover { color: #15171F; }
.tabs button.is-active {
  /* a docs page has no colourway, so the fallback is its own ink */
  background: #FFFFFF; color: var(--accent, #15171F); font-weight: 500;
  box-shadow: 2px 2px 0 rgba(21,23,31,.16), inset 0 0 0 1px rgba(21,23,31,.14);
  transform: translate(1px, 1px);
}