/* shell.css — the canonical nerdz shared shell: header (Topbar), footer
   (Colophon), the .frame primitive, the handful of utilities the shell
   markup uses, and the View Transitions opt-in.
   SOURCE OF TRUTH: nerdz/docs/unified-shell-spec.md §2 + §5. Do not edit a
   copy; edit the spec, then re-sync both repos (nerdz-landing + nerdz-blog).
   Reads design tokens from shell-tokens.css. */

/* ─── seamless navigation (§5) ──────────────────────────────
   Opt this document into cross-document View Transitions for same-origin
   navigations. Naming the chrome makes the browser carry it ACROSS the
   navigation (it stays fixed) instead of cross-fading it. Pure progressive
   enhancement: unsupported browsers just do an ordinary navigation. */
@view-transition { navigation: auto; }
.shell-topbar   { view-transition-name: shell-topbar; }
.shell-colophon { view-transition-name: shell-colophon; }

/* ─── shared primitives + utilities ─────────────────────────── */
.frame {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  position: relative;
}
.mono { font-family: var(--font-mono); }
.gold { color: var(--gold); }
.sep  { color: var(--ink-veryDim); }

/* ─── skip link ─────────────────────────────────────────────── */
.shell-skip {
  position: absolute;
  left: -9999px; top: 0;
  z-index: 100;
  background: var(--paper-soft);
  color: var(--ink);
  padding: 10px 16px;
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 12px;
}
.shell-skip:focus { left: 16px; top: 12px; }

/* ─── TOPBAR ────────────────────────────────────────────────── */
.shell-topbar {
  position: sticky;
  top: 0; z-index: 50;
  background: var(--paper);
  border-bottom: 1px solid var(--rule-strong);
}
.shell-topbar__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 32px;
  padding: 18px 0;
}
.shell-topbar__brand {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: -0.01em;
}
.shell-topbar__dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--glow); box-shadow: 0 0 8px var(--glow);
}
/* live telemetry pill — <nerdz-status> renders its light-DOM content here */
.shell-topbar__status {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-mute);
  display: inline-flex; gap: 14px; align-items: center;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  justify-self: center;
  min-height: 1em;
}
.shell-topbar__status .gold { letter-spacing: 0.14em; }
.shell-topbar__nav {
  display: inline-flex; align-items: center; gap: 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-mute);
  text-transform: lowercase;
  letter-spacing: 0.04em;
}
.shell-topbar__nav a { transition: color 200ms ease; position: relative; }
.shell-topbar__nav a:hover { color: var(--glow); }
.shell-topbar__nav a[aria-current="page"] { color: var(--ink); }
.shell-topbar__nav a[aria-current="page"]::after {
  content: ''; position: absolute;
  left: 0; right: 0; bottom: -6px;
  height: 1px; background: var(--glow);
}
.shell-topbar__nav a.cta { color: var(--gold); }

/* hamburger — hidden on desktop, shown when the inline nav collapses */
.shell-topbar__menu {
  display: none;
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--ink-mute);
  justify-self: end;
}

/* ─── mobile drawer ─────────────────────────────────────────── */
.shell-drawer {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 8px 0 18px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-mono);
  font-size: 15px;
  text-transform: lowercase;
}
.shell-drawer[hidden] { display: none; }
.shell-drawer a {
  padding: 10px var(--gutter);
  color: var(--ink-mid);
  transition: color 200ms ease;
}
.shell-drawer a:hover,
.shell-drawer a[aria-current="page"] { color: var(--ink); }
.shell-drawer a.cta { color: var(--gold); }

@media (max-width: 900px) {
  .shell-topbar__inner { grid-template-columns: auto auto; }
  .shell-topbar__status { display: none; }
  .shell-topbar__nav { display: none; }
  .shell-topbar__menu { display: inline-flex; }
}

/* ─── COLOPHON ──────────────────────────────────────────────── */
.shell-colophon {
  position: relative;
  padding: 96px 0 48px;
  border-top: 1px solid var(--rule);
  background: linear-gradient(180deg, transparent, rgba(106, 13, 173, 0.08));
}
/* Light-mode: deeper, lower-alpha purple wash so the cream still gets a hint
   of brand without the dark-mode 0.08 reading as cool-pink on cream. */
[data-theme="light"] .shell-colophon {
  background: linear-gradient(180deg, transparent, rgba(90, 14, 147, 0.05));
}
.shell-colophon__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 56px;
}
@media (max-width: 980px) { .shell-colophon__grid { grid-template-columns: 1fr 1fr; gap: 32px; } }
@media (max-width: 540px) { .shell-colophon__grid { grid-template-columns: 1fr; } }
.shell-colophon h4 {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--gold);
  text-transform: uppercase;
  letter-spacing: 0.24em;
  margin: 0 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}
.shell-colophon__pitch {
  font-family: var(--font-sans);
  font-size: 26px;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 0 0 24px;
  max-width: 28ch;
  text-wrap: balance;
}
.shell-colophon__pitch em {
  font-family: var(--font-sans);
  font-style: italic;
  color: var(--gold);
  font-weight: 400;
}
.shell-colophon__btn-row { display: flex; gap: 12px; flex-wrap: wrap; }
.shell-colophon__list {
  list-style: none; padding: 0; margin: 0;
  display: flex; flex-direction: column; gap: 10px;
}
.shell-colophon__list a {
  color: var(--ink-mid);
  font-size: 15px;
  transition: color 200ms ease;
  display: inline-flex; align-items: baseline; gap: 8px;
}
.shell-colophon__list a:hover { color: var(--gold); }
.shell-colophon__list .arr {
  color: var(--ink-dim);
  font-family: var(--font-mono);
  font-size: 11px;
}
.shell-colophon__credit {
  font-family: var(--font-sans);
  font-style: italic;
  color: var(--ink-mute);
  font-size: 15px;
  line-height: 1.6;
}
.shell-colophon__credit em { color: var(--gold); font-style: italic; }

/* ─── imprint row ───────────────────────────────────────────── */
.shell-imprint {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 32px;
  align-items: center;
  padding-top: 28px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-mute);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}
.shell-imprint__brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--ink);
}
.shell-imprint__dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--glow); box-shadow: 0 0 6px var(--glow);
}
.shell-imprint__center { text-align: center; color: var(--ink-mute); }
.shell-imprint__center .gold { letter-spacing: 0.18em; }
.shell-imprint__right { text-align: right; }
@media (max-width: 720px) {
  .shell-imprint { grid-template-columns: 1fr; text-align: center; gap: 12px; }
  .shell-imprint__center, .shell-imprint__right, .shell-imprint__brand { justify-content: center; }
}

/* ── PALETTE TOGGLE (sun/moon) ──────────────────────────────── */
.palette-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  margin-left: 4px;
  color: var(--ink-mute);
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  transition: color 200ms ease, border-color 200ms ease;
}
.palette-toggle:hover { color: var(--ink); border-color: var(--glow); }
.palette-toggle svg { display: block; }

/* In the mobile drawer, render as a labelled row to match the nav items. */
.shell-drawer .palette-toggle {
  width: auto;
  height: auto;
  padding: 10px var(--gutter);
  margin: 0;
  justify-content: flex-start;
  border: 0;
  border-radius: 0;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 15px;
  text-transform: lowercase;
  color: var(--ink-mid);
}
.shell-drawer .palette-toggle::after { content: "theme"; }