/* Nio site — shared design tokens, topbar, sidebar, page shell.
   Source of truth for palette/typography/layout used across index.html and /docs/*. */

/* ── font faces — latin subset only (matches filenames index.html uses for U+0000-00FF range) ── */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('fonts/Inter-02046d.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('fonts/Inter-02046d.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url('fonts/Inter-02046d.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('fonts/Inter-02046d.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('fonts/JetBrainsMono-d4015e.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('fonts/JetBrainsMono-d4015e.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url('fonts/JetBrainsMono-d4015e.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('fonts/JetBrainsMono-d4015e.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* ── design tokens ── */
:root {
  --bg-0: oklch(0.16 0.012 260);
  --bg-1: oklch(0.20 0.012 260);
  --bg-2: oklch(0.24 0.014 260);
  --bg-card: oklch(0.22 0.013 260);
  --line: oklch(0.32 0.012 260);
  --line-soft: oklch(0.28 0.012 260);
  --fg-0: oklch(0.97 0.008 260);
  --fg-1: oklch(0.82 0.012 260);
  --fg-2: oklch(0.62 0.014 260);
  --fg-3: oklch(0.48 0.012 260);

  --sev-0: oklch(0.78 0.16 150);
  --sev-1: oklch(0.82 0.15 130);
  --sev-2: oklch(0.84 0.16 95);
  --sev-3: oklch(0.78 0.17 65);
  --sev-4: oklch(0.74 0.18 45);
  --sev-5: oklch(0.68 0.20 25);
  --sev-6: oklch(0.62 0.22 15);

  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  --font-sans: 'Inter', system-ui, sans-serif;

  --sidebar-w: 260px;
  --grid-col-gap: 56px;
}

* { box-sizing: border-box; }

/* default link color — the theme yellow. More-specific selectors (.brand,
   .sidebar a, .page-nav a, .pill.link) override below. */
a { color: var(--sev-2); text-decoration: none; }
a:hover { text-decoration: underline; }

html, body {
  margin: 0; padding: 0;
  background: var(--bg-0);
  color: var(--fg-0);
  font-family: var(--font-sans);
  font-feature-settings: 'ss01', 'cv11';
  min-height: 100vh;
  /* `clip` keeps horizontal overflow contained without creating a scroll
     container — preserves `position: sticky` on .sidebar. Don't use `hidden`. */
  overflow-x: clip;
}
/* `isolation: isolate` makes body its own stacking context so the
   backdrop pseudo-element (`body::before { z-index: -1 }`) renders above
   body's background but below body's content, without any descendant
   needing to set `z-index: 1` (which would trap mobile sidebar/overlay). */
body { isolation: isolate; }

body::before {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(to right, oklch(0.24 0.01 260 / 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, oklch(0.24 0.01 260 / 0.4) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 40%, black 40%, transparent 100%);
  pointer-events: none;
  /* sit behind every content layer so opaque blocks (pre, cards, topbar)
     fully cover the grid. body must allow this — see html, body block. */
  z-index: -1;
}
body.no-grid::before { display: none; }

.app {
  /* no stacking context here — sidebar (position:fixed) and overlay
     (body::after) need to stack at the root, not be trapped inside .app. */
  max-width: 1720px;
  margin: 0 auto;
  /* horizontal gutter + bottom space live on .topbar / .body-grid below */
  padding: 0;
}

/* ── topbar — sticky at top, frosted ── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in oklch, var(--bg-0) 72%, transparent);
  backdrop-filter: blur(10px) saturate(1.2);
  -webkit-backdrop-filter: blur(10px) saturate(1.2);
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 40px;
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 32px;
}
.topbar-left { display: flex; align-items: center; gap: 10px; }
.brand {
  display: flex; align-items: center; gap: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--fg-1);
  letter-spacing: 0.02em;
  text-decoration: none;
}
.brand-mark {
  width: 26px; height: 26px;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--bg-1);
}
.brand b { color: var(--fg-0); font-weight: 600; letter-spacing: 0.04em; }
.brand .sep { color: var(--fg-3); }
.brand a { color: inherit; text-decoration: none; }
.brand a:hover { color: var(--fg-0); }
.brand-home { display: inline-flex; align-items: center; }

.topbar-right {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-2);
}
.pill {
  height: 24px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg-1);
  display: inline-flex; align-items: center; gap: 6px;
  line-height: 1;
  text-decoration: none;
  color: inherit;
}
.pill .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--sev-0);
  box-shadow: 0 0 6px var(--sev-0);
}
.pill.link:hover { border-color: var(--fg-3); background: var(--bg-card); color: var(--fg-0); }

.hamburger {
  display: none;
  appearance: none;
  background: var(--bg-1);
  border: 1px solid var(--line);
  color: var(--fg-1);
  border-radius: 6px;
  width: 32px; height: 28px;
  cursor: pointer;
  padding: 0;
  align-items: center; justify-content: center;
  margin-right: 10px;
}
.hamburger svg { display: block; }

/* ── body grid ── */
.body-grid {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  column-gap: var(--grid-col-gap);
  align-items: start;
  padding: 0 40px 80px;
}
.body-grid > * { min-width: 0; }
.main { min-width: 0; overflow-x: clip; }

/* ── sidebar ── */
.sidebar {
  position: sticky;
  top: 100px;
  font-family: var(--font-sans);
  font-size: 13.5px;
  color: var(--fg-1);
  padding-right: 8px;
  max-height: calc(100vh - 124px);
  overflow-y: auto;
}
.sidebar details {
  border-bottom: 1px solid var(--line-soft);
  padding: 10px 0;
}
.sidebar details:last-child { border-bottom: none; }
.sidebar summary {
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-2);
  padding: 4px 2px;
  display: flex; align-items: center; justify-content: space-between;
  user-select: none;
  transition: color .2s ease;
}
.sidebar summary:hover { color: var(--fg-0); }
.sidebar summary::-webkit-details-marker { display: none; }
.sidebar summary::after {
  content: '▸';
  font-size: 10px;
  color: var(--fg-3);
  transition: transform .2s ease;
}
.sidebar details[open] > summary::after { transform: rotate(90deg); }

.sidebar nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 6px;
}
.sidebar nav a {
  position: relative;
  display: block;
  padding: 6px 10px 6px 16px;
  color: var(--fg-1);
  text-decoration: none;
  border-radius: 4px;
  font-size: 13.5px;
  line-height: 1.35;
  transition: background .18s ease, color .18s ease;
}
.sidebar nav a:hover { background: var(--bg-card); color: var(--fg-0); }
.sidebar nav a.current {
  color: var(--fg-0);
  background: color-mix(in oklch, var(--sev-2) 8%, var(--bg-1));
}
.sidebar nav a.current::before {
  content: '';
  position: absolute;
  left: 0; top: 6px; bottom: 6px;
  width: 3px;
  background: var(--sev-2);
  border-radius: 2px;
}

/* ── page shell (doc pages) ── */
.doc-hero {
  margin-bottom: 40px;
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--fg-2);
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex; align-items: center; gap: 8px;
}
.eyebrow::before {
  content: '';
  width: 24px; height: 1px;
  background: var(--fg-3);
}
.doc-hero h1 {
  font-family: var(--font-sans);
  font-size: 44px;
  line-height: 1.08;
  letter-spacing: -0.025em;
  margin: 0 0 16px;
  font-weight: 600;
  max-width: 720px;
  color: var(--fg-0);
}
.doc-hero h1 em {
  font-style: normal;
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--sev-2);
  background: linear-gradient(180deg, transparent 60%, oklch(0.84 0.16 95 / 0.18) 60%);
  padding: 0 4px;
}
.doc-hero p.lead {
  font-size: 15px;
  color: var(--fg-1);
  max-width: 640px;
  line-height: 1.6;
  margin: 0;
}

.doc {
  max-width: 820px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--fg-1);
}
.doc h2 {
  font-family: var(--font-sans);
  font-size: 22px;
  color: var(--fg-0);
  margin: 48px 0 12px;
  letter-spacing: -0.01em;
  font-weight: 600;
}
.doc h3 {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--fg-2);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 32px 0 10px;
  font-weight: 600;
}
.doc h4 {
  font-family: var(--font-sans);
  font-size: 15.5px;
  color: var(--fg-0);
  margin: 24px 0 8px;
  font-weight: 600;
}
.doc p { margin: 0 0 14px; }
.doc a {
  color: var(--sev-2);
  text-decoration: none;
  border-bottom: 1px dotted color-mix(in oklch, var(--sev-2) 40%, transparent);
  transition: border-color .18s ease;
}
.doc a:hover { border-bottom-color: var(--sev-2); }
.doc strong { color: var(--fg-0); font-weight: 600; }
.doc em { font-style: italic; color: var(--fg-0); }
.doc ul, .doc ol { margin: 8px 0 16px; padding-left: 22px; }
.doc li { margin-bottom: 6px; }
.doc li > ul, .doc li > ol { margin: 6px 0 2px; }

.doc code {
  font-family: var(--font-mono);
  font-size: 12.5px;
  background: var(--bg-2);
  color: var(--fg-0);
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid var(--line-soft);
}
.doc pre {
  font-family: var(--font-mono);
  font-size: 12.5px;
  background: var(--bg-1);
  color: var(--fg-0);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
  overflow-x: auto;
  line-height: 1.55;
  margin: 8px 0 20px;
}
.doc pre code {
  background: transparent;
  border: none;
  padding: 0;
  font-size: inherit;
}

/* ── tables ── */
.doc table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 8px 0 20px;
  font-family: var(--font-sans);
}
.doc th, .doc td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line-soft);
  text-align: left;
  vertical-align: top;
}
.doc th {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-2);
  font-weight: 500;
  background: var(--bg-1);
  border-bottom-color: var(--line);
}
.doc td code { font-size: 11.5px; }
.doc tr:hover td { background: color-mix(in oklch, var(--bg-card) 50%, transparent); }

/* ── generic card ── */
.card {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg-1);
  padding: 18px 20px;
  margin: 10px 0 20px;
  transition: border-color .2s ease, background .2s ease;
}
.card:hover { border-color: var(--fg-3); background: var(--bg-card); }
.card > :first-child { margin-top: 0; }
.card > :last-child { margin-bottom: 0; }

.card-head {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--fg-0);
  margin-bottom: 6px;
}
.card-head .tag {
  font-size: 9.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-3);
  padding: 2px 6px;
  border: 1px solid var(--line);
  border-radius: 3px;
}
.card-head .tag.sev-low    { color: var(--sev-0); border-color: var(--sev-0); }
.card-head .tag.sev-med    { color: var(--sev-2); border-color: var(--sev-2); }
.card-head .tag.sev-high   { color: var(--sev-4); border-color: var(--sev-4); }
.card-head .tag.sev-crit   { color: var(--sev-6); border-color: var(--sev-6); }

/* ── callouts ── */
.callout {
  border: 1px solid var(--line);
  border-left: 3px solid var(--sev-2);
  border-radius: 6px;
  background: color-mix(in oklch, var(--sev-2) 6%, var(--bg-1));
  padding: 12px 16px;
  margin: 14px 0 22px;
  font-size: 13.5px;
  color: var(--fg-1);
}
.callout.warn { border-left-color: var(--sev-4); background: color-mix(in oklch, var(--sev-4) 6%, var(--bg-1)); }
.callout.danger { border-left-color: var(--sev-6); background: color-mix(in oklch, var(--sev-6) 6%, var(--bg-1)); }
.callout.ok { border-left-color: var(--sev-0); background: color-mix(in oklch, var(--sev-0) 6%, var(--bg-1)); }
.callout > :first-child { margin-top: 0; }
.callout > :last-child { margin-bottom: 0; }
.callout .title {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-2);
  margin-bottom: 6px;
  font-weight: 500;
}

/* ── prev/next footer ── */
.page-nav {
  display: flex; justify-content: space-between; gap: 16px;
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
}
.page-nav a {
  display: flex; flex-direction: column; gap: 3px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-1);
  color: var(--fg-1);
  text-decoration: none;
  transition: border-color .18s ease, background .18s ease, color .18s ease;
  min-width: 200px;
}
.page-nav a:hover { border-color: var(--fg-3); background: var(--bg-card); color: var(--fg-0); }
.page-nav a .dir {
  font-size: 9.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-3);
}
.page-nav a .label {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--fg-0);
  font-weight: 500;
}
.page-nav .spacer { flex: 1; }
.page-nav a.next { text-align: right; align-items: flex-end; margin-left: auto; }

/* ── back-to-top floating button ── */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in oklch, var(--bg-1) 72%, transparent);
  backdrop-filter: blur(10px) saturate(1.2);
  -webkit-backdrop-filter: blur(10px) saturate(1.2);
  color: var(--fg-1);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .2s ease, transform .2s ease, border-color .2s ease, color .2s ease, background .2s ease;
  z-index: 9;
  appearance: none;
  padding: 0;
}
.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover {
  border-color: var(--fg-2);
  color: var(--fg-0);
  background: color-mix(in oklch, var(--bg-card) 85%, transparent);
}
.back-to-top svg { display: block; }

/* ── footer ── */
.site-footer {
  margin-top: 80px;
  padding-top: 24px;
  border-top: 1px solid var(--line-soft);
  display: flex; justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--fg-3);
  text-transform: uppercase;
}
.site-footer a { color: inherit; text-decoration: none; }
.site-footer a:hover { color: var(--fg-0); }

/* ── responsive ── */
@media (max-width: 1080px) {
  .topbar { padding: 20px 24px; }
  .body-grid { padding: 0 24px 60px; }
}
@media (max-width: 960px) {
  .hamburger { display: inline-flex; }
  .body-grid { grid-template-columns: minmax(0, 1fr); }
  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    width: 280px;
    max-height: 100vh;
    padding: 24px 20px;
    background: var(--bg-1);
    border-right: 1px solid var(--line);
    z-index: 20;
    transform: translateX(-100%);
    transition: transform .25s ease;
    box-shadow: 20px 0 40px -16px oklch(0 0 0 / 0.4);
  }
  body.sidebar-open .sidebar { transform: translateX(0); }
  body.sidebar-open::after {
    content: '';
    position: fixed; inset: 0;
    background: oklch(0 0 0 / 0.55);
    z-index: 15;
  }
  .doc-hero h1 { font-size: 32px; }
  .doc h2 { font-size: 19px; }
}
@media (max-width: 560px) {
  .topbar-right .pill:not(.status) { display: none; }
  .page-nav { flex-direction: column; }
  .page-nav a.next { text-align: left; align-items: flex-start; margin-left: 0; }
}