/* Shared structural styles for both editions. Colors come entirely from the
   active theme file's token contract; this file never hard-codes brand colors. */

html { scroll-behavior: smooth; background: var(--bg); }

/* Themed scrollbars (desktop / precise pointers). Colors come from the token
   contract, so each edition + light/dark theme gets its own automatically:
   a muted thumb derived from --ink, brightening to the brand --accent on hover. */
@media (pointer: fine) {
  html { scrollbar-width: thin; scrollbar-color: color-mix(in srgb, var(--ink) 26%, transparent) transparent; }
  ::-webkit-scrollbar { width: 11px; height: 11px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb { background: color-mix(in srgb, var(--ink) 22%, transparent); border-radius: 7px; }
  ::-webkit-scrollbar-thumb:hover { background: var(--accent); }
  ::-webkit-scrollbar-corner { background: transparent; }
}
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  transition: background .3s ease, color .3s ease;
  min-height: 100vh;
}

.page { display: flex; flex-direction: column; min-height: 100vh; position: relative; }
.container { max-width: 1180px; margin: 0 auto; padding-left: 32px; padding-right: 32px; }
main { flex: 1; }

/* Opt-in vertical centering: a page wraps its content in `.page-center` to have
   it centered in the space between nav and footer. main already fills that space
   (flex:1 in the full-height .page); making it a column flex context lets the
   wrapper's auto block margins center it vertically. The wrapper itself stays a
   plain block, so its sections keep their normal full-width left-aligned flow. */
main:has(> .page-center) { display: flex; flex-direction: column; }
.page-center { margin-block: auto; }


h1, h2, h3, h4 { font-family: var(--font-display); letter-spacing: -.02em; line-height: 1.1; }
.eyebrow {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: .16em;
  text-transform: uppercase; color: var(--eyebrow);
}
.muted { color: var(--muted); }
.accent { color: var(--accent); }
code { color: var(--accent); }

/* ---- buttons ---- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  font-weight: 600; font-size: 14px; padding: 13px 24px; border-radius: 999px;
  border: 1px solid transparent; cursor: pointer; white-space: nowrap;
  transition: filter .15s ease, background-color .15s ease, border-color .15s ease, box-shadow .15s ease, color .15s ease;
}
.btn-primary { background: var(--accent); color: var(--on-accent); }
.btn-gradient { background: linear-gradient(100deg, var(--accent), var(--accent2)); background-origin: border-box; color: #fff; }
.btn-ghost { border-color: var(--line); color: var(--ink); background: none; }
/* Hover: subtle in-place feedback — no translate, so buttons don't jump.
   Each variant re-asserts its own text color; the global `a:hover` (reset.css)
   would otherwise recolor the label to --accent and tank contrast. */
.btn-primary:hover { color: var(--on-accent); filter: brightness(1.06); }
.btn-gradient:hover { color: #fff; filter: brightness(1.08); }
.btn-ghost:hover { color: var(--ink); border-color: var(--accent); background: color-mix(in srgb, var(--accent) 10%, transparent); }
.btn-sm { padding: 9px 16px; font-size: 13px; border-radius: 8px; }

/* ---- cross-ref ribbon ---- */
.ribbon {
  position: relative; z-index: 61;
  background: var(--surface2); border-bottom: 1px solid var(--line);
}
.ribbon .container { padding-top: 9px; padding-bottom: 9px; text-align: center; font-size: 13px; line-height: 1.55; color: var(--muted); }
.ribbon a { color: var(--accent); font-weight: 600; white-space: nowrap; }

/* ---- nav ---- */
.nav {
  position: sticky; top: -1px; z-index: 60;
  background: var(--navbg); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; gap: 20px; height: 74px; }
/* Brand lockup: square glyph left of a name(+optional slogan) text block.
   Common pattern across logo variants — the glyph is sized to the text block's
   height: name-only for the plain variant, name+slogan for the stacked variant.
   --mark holds that height per variant. */
.brand { --mark: 15px; display: inline-flex; align-items: center; gap: 16px; margin-right: auto; color: var(--accent); }
.brand--stacked { --mark: 35px; }
.brand--lg { --mark: 17px; }
.brand--lg.brand--stacked { --mark: 37px; }
.brand__mark { display: flex; align-items: center; flex: none; }
/* glyph viewBox is 42x28 (tight to the artwork) -> width = height * 1.5 */
.brand__mark svg { height: var(--mark); width: calc(var(--mark) * 1.5); display: block; }
.brand__text { display: flex; flex-direction: column; justify-content: center; }
/* Brand name always uses the Flux (.com) display face so the logo is identical
   across editions, regardless of each theme's --font-display. */
.brand__name { font-family: 'Space Grotesk', system-ui, sans-serif; font-weight: 700; font-size: 17px; line-height: 1.05; letter-spacing: -.02em; color: var(--ink); }
.brand__slogan { font-family: var(--font-mono); font-size: 11.4px; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); line-height: 1.1; margin-top: 9px; }
.brand--lg .brand__name { font-size: 19px; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.nav-link {
  font-family: var(--font-mono); font-size: 14.5px; font-weight: 500;
  padding: 8px 12px; border-radius: 8px; color: var(--ink); white-space: nowrap;
}
.nav-link:hover { color: var(--accent); }
.nav-link.active { color: var(--accent); font-weight: 600; }
.nav-outline { border: 1px solid var(--line); padding: 8px 13px; border-radius: 8px; font-family: var(--font-mono); font-size: 14px; white-space: nowrap; }

.burger {
  display: none; width: 40px; height: 40px; align-items: center; justify-content: center;
  border: 1px solid var(--line); border-radius: 8px; color: var(--ink);
}

/* mobile nav drawer */
.mobile-nav { display: none; border-top: 1px solid var(--line); background: var(--navbg); backdrop-filter: blur(14px); }
.mobile-nav.open { display: block; }
.mobile-nav .container { display: flex; flex-direction: column; padding-top: 8px; padding-bottom: 16px; }
.mobile-nav a { padding: 13px 6px; color: var(--ink); font-size: 15px; border-bottom: 1px solid var(--line); }
.mobile-nav a:last-child { border-bottom: none; }

/* ---- theme toggle (segmented) ---- */
.theme-toggle { display: inline-flex; align-items: center; gap: 2px; border: 1px solid var(--line); border-radius: 8px; padding: 2px; }
.theme-toggle button {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 6px; color: var(--muted);
}
.theme-toggle button[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); }

/* ---- cards ---- */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 28px 24px; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--muted); line-height: 1.6; }

.grid { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.section { padding-top: 44px; padding-bottom: 44px; }
/* container-query context (kept for any component that opts into @container) */
.section-label { font-family: var(--font-mono); font-size: 12px; letter-spacing: .16em; color: var(--muted); margin-bottom: 20px; }

/* ---- footer ---- */
.footer { border-top: 1px solid var(--line); background: var(--surface2); margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; padding-top: 48px; padding-bottom: 30px; }
.footer h4 { font-family: var(--font-mono); color: var(--muted); letter-spacing: .1em; font-size: 12px; margin-bottom: 12px; font-weight: 600; text-transform: uppercase; }
.footer-links { display: flex; flex-direction: column; gap: 9px; font-size: 13.5px; }
.footer-links a:hover { color: var(--accent); }
.footer-brand-desc { font-size: 13.5px; color: var(--muted); line-height: 1.6; max-width: 260px; margin-top: 4px; }
.footer-bottom { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; padding-top: 18px; padding-bottom: 40px; border-top: 1px solid var(--line); font-size: 14.5px; color: var(--muted); }

/* ---- tutorial layout (chapter sidebar + content) ---- */
.tut-layout { display: grid; grid-template-columns: 240px 1fr; gap: 44px; align-items: start; }
.tut-side { position: sticky; top: 90px; font-family: var(--font-mono); font-size: 13px; }
.tut-side .lbl { color: var(--muted); letter-spacing: .12em; text-transform: uppercase; font-size: 12px; margin-bottom: 14px; }
.tut-ch { display: block; padding: 10px 12px; border-radius: 8px; color: var(--muted); margin-bottom: 2px; }
.tut-ch:hover { color: var(--accent); }
.tut-ch.active { background: var(--accent); color: var(--on-accent); font-weight: 600; }
.tut-nav { display: flex; justify-content: space-between; gap: 12px; border-top: 1px solid var(--line); margin-top: 36px; padding-top: 22px; }
.tut-nav a { font-family: var(--font-mono); font-size: 13px; border: 1px solid var(--line); padding: 10px 16px; border-radius: 8px; color: var(--ink); }
.tut-nav a:hover { border-color: var(--accent); color: var(--accent); }
.tut-nav .next { background: var(--accent); color: var(--on-accent); border-color: transparent; font-weight: 600; }
.tut-nav .next:hover { color: var(--on-accent); }
@media (max-width: 860px) {
  .tut-layout { grid-template-columns: minmax(0, 1fr); }
  .tut-side { position: static; margin-bottom: 24px; }
}

/* ---- responsive (media queries) ---- */
/* Nav collapses to the burger *before* its items would run out of room and wrap.
   The com (Flux) nav carries more items than org (Terminal), so each edition
   switches at its own measured width. */
@media (max-width: 940px) {
  [data-skin="flux"] .nav-links, [data-skin="flux"] .nav-actions { display: none; }
  [data-skin="flux"] .burger { display: inline-flex; }
}
@media (max-width: 860px) {
  [data-skin="terminal"] .nav-links, [data-skin="terminal"] .nav-actions { display: none; }
  [data-skin="terminal"] .burger { display: inline-flex; }
}
/* ≤760px = content mobile layout */
@media (max-width: 760px) {
  .nav-links, .nav-actions { display: none; }
  .burger { display: inline-flex; }
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  h1 { font-size: 34px !important; }
  h2 { font-size: 26px !important; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
}