/* Firewire Help Center — self-contained stylesheet (brand-consistent, light/dark) */

:root {
  --bg: #0b121a;
  --surface: #151f2b;
  --surface-2: #1c2836;
  --text-primary: #e6ecf3;
  --text-secondary: #9fb0c3;
  --text-muted: #6b7b8f;
  --border: #24303f;
  --accent: #3cae70;
  --accent-hover: #4cbf80;
  --accent-soft: rgba(60, 174, 112, 0.12);
  --warn: #e0a44a;
  --warn-soft: rgba(224, 164, 74, 0.12);
  --info: #4a94e0;
  --info-soft: rgba(74, 148, 224, 0.12);
  --radius: 14px;
  --radius-sm: 8px;
  --maxw: 1160px;
  --measure: 720px;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #eceef2;
    --surface: #ffffff;
    --surface-2: #f4f6f9;
    --text-primary: #1a2230;
    --text-secondary: #4a5a6e;
    --text-muted: #7d8798;
    --border: #dce1e8;
    --accent: #2fa968;
    --accent-hover: #268a55;
    --accent-soft: rgba(47, 169, 104, 0.10);
    --warn: #b9791f;
    --warn-soft: rgba(185, 121, 31, 0.10);
    --info: #2b6fb8;
    --info-soft: rgba(43, 111, 184, 0.09);
  }
}

:root[data-theme="light"] {
  --bg: #eceef2;
  --surface: #ffffff;
  --surface-2: #f4f6f9;
  --text-primary: #1a2230;
  --text-secondary: #4a5a6e;
  --text-muted: #7d8798;
  --border: #dce1e8;
  --accent: #2fa968;
  --accent-hover: #268a55;
  --accent-soft: rgba(47, 169, 104, 0.10);
  --warn: #b9791f;
  --warn-soft: rgba(185, 121, 31, 0.10);
  --info: #2b6fb8;
  --info-soft: rgba(43, 111, 184, 0.09);
}

:root[data-theme="dark"] {
  --bg: #0b121a;
  --surface: #151f2b;
  --surface-2: #1c2836;
  --text-primary: #e6ecf3;
  --text-secondary: #9fb0c3;
  --text-muted: #6b7b8f;
  --border: #24303f;
  --accent: #3cae70;
  --accent-hover: #4cbf80;
  --accent-soft: rgba(60, 174, 112, 0.12);
  --warn: #e0a44a;
  --warn-soft: rgba(224, 164, 74, 0.12);
  --info: #4a94e0;
  --info-soft: rgba(74, 148, 224, 0.12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header .nav {
  display: flex; align-items: center; gap: 20px;
  height: 62px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: -0.02em; }
.brand img { height: 26px; width: auto; display: block; }
.brand .logo-light-img { display: none; }
:root[data-theme="light"] .brand .logo-dark-img { display: none; }
:root[data-theme="light"] .brand .logo-light-img { display: block; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .brand .logo-dark-img { display: none; }
  :root:not([data-theme]) .brand .logo-light-img { display: block; }
}
.brand .kb-badge {
  font-size: 11px; font-weight: 700; color: var(--accent);
  background: var(--accent-soft); padding: 2px 8px; border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
}
.nav-links { display: flex; gap: 4px; margin-left: auto; align-items: center; list-style: none; padding: 0; }
.nav-links a {
  color: var(--text-secondary); font-weight: 600; font-size: 14px;
  padding: 8px 12px; border-radius: var(--radius-sm);
}
.nav-links a:hover { color: var(--text-primary); background: var(--surface-2); text-decoration: none; }
.icon-btn {
  display: inline-grid; place-items: center; width: 38px; height: 38px;
  border: 1px solid var(--border); background: var(--surface); color: var(--text-secondary);
  border-radius: var(--radius-sm); cursor: pointer;
}
.icon-btn:hover { color: var(--text-primary); border-color: var(--accent); }
.icon-btn .moon { display: none; }
:root[data-theme="dark"] .icon-btn .sun { display: none; }
:root[data-theme="dark"] .icon-btn .moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) .icon-btn .sun { display: none; }
  :root:not([data-theme]) .icon-btn .moon { display: block; }
}
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 700; font-size: 14px; padding: 9px 16px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); cursor: pointer; transition: all .15s ease;
}
.btn-primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-hover); color: #fff; text-decoration: none; }
.btn-ghost { background: transparent; color: var(--text-primary); }
.btn-ghost:hover { border-color: var(--accent); text-decoration: none; }

/* ---------- Hero (home) ---------- */
.hero { padding: 64px 0 32px; text-align: center; }
.hero h1 { font-size: clamp(30px, 5vw, 46px); line-height: 1.1; letter-spacing: -0.03em; margin: 0 0 14px; }
.hero p { color: var(--text-secondary); font-size: 18px; max-width: 640px; margin: 0 auto 26px; }
.search-hint {
  display: inline-flex; align-items: center; gap: 8px; color: var(--text-muted);
  font-size: 13px; border: 1px dashed var(--border); border-radius: 999px; padding: 6px 14px;
}

/* ---------- Card grid ---------- */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; }
.card {
  display: block; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px; transition: border-color .15s ease, transform .15s ease;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.card .card-kicker { font-size: 12px; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; color: var(--accent); }
.card h3 { margin: 8px 0 6px; font-size: 18px; color: var(--text-primary); letter-spacing: -0.01em; }
.card p { margin: 0; color: var(--text-secondary); font-size: 14.5px; }

.section-head { margin: 48px 0 18px; }
.section-head h2 { font-size: 24px; letter-spacing: -0.02em; margin: 0 0 4px; }
.section-head p { color: var(--text-muted); margin: 0; font-size: 15px; }

/* ---------- Article layout ---------- */
.doc-wrap { display: grid; grid-template-columns: minmax(0, 1fr) 240px; gap: 48px; padding: 32px 0 72px; align-items: start; }
@media (max-width: 940px) { .doc-wrap { grid-template-columns: 1fr; } .toc { display: none; } }

.breadcrumbs { font-size: 13px; color: var(--text-muted); margin-bottom: 18px; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.breadcrumbs a { color: var(--text-secondary); }
.breadcrumbs .sep { color: var(--border); }

.article { max-width: var(--measure); }
.article h1 { font-size: clamp(28px, 4vw, 40px); line-height: 1.12; letter-spacing: -0.03em; margin: 6px 0 10px; }
.article .lead { font-size: 19px; color: var(--text-secondary); margin: 0 0 8px; }
.article .meta { color: var(--text-muted); font-size: 13px; margin-bottom: 30px; }
.article h2 { font-size: 25px; letter-spacing: -0.02em; margin: 44px 0 14px; padding-top: 8px; scroll-margin-top: 80px; }
.article h3 { font-size: 19px; margin: 30px 0 10px; scroll-margin-top: 80px; }
.article p, .article li { font-size: 16.5px; color: var(--text-primary); }
.article ul, .article ol { padding-left: 22px; }
.article li { margin: 6px 0; }
.article strong { color: var(--text-primary); }
.article em { color: var(--text-secondary); }
.article a { text-decoration: underline; text-underline-offset: 2px; }
.article hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }

/* Formula block (no external math libs — CSP-safe) */
.formula {
  background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm); padding: 18px 20px; margin: 20px 0;
  font-family: var(--mono); font-size: 17px; color: var(--text-primary);
  overflow-x: auto; text-align: center; line-height: 1.9;
}
.formula .where { display: block; margin-top: 10px; font-family: var(--sans); font-size: 13.5px; color: var(--text-muted); text-align: left; }
.frac { display: inline-flex; flex-direction: column; vertical-align: middle; text-align: center; margin: 0 4px; }
.frac > span:first-child { border-bottom: 1.5px solid currentColor; padding: 0 6px 2px; }
.frac > span:last-child { padding: 2px 6px 0; }

/* Callouts */
.callout { border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 14px 18px; margin: 22px 0; display: flex; gap: 12px; font-size: 15px; color: var(--text-secondary); }
.callout strong { color: var(--text-primary); }
.callout .ic { flex: none; width: 20px; height: 20px; margin-top: 2px; }
.callout.info { background: var(--info-soft); border-color: color-mix(in srgb, var(--info) 30%, transparent); }
.callout.info .ic { color: var(--info); }
.callout.warn { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 30%, transparent); }
.callout.warn .ic { color: var(--warn); }
.callout.tip { background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 30%, transparent); }
.callout.tip .ic { color: var(--accent); }

/* Example box */
.example { background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 22px; margin: 24px 0; }
.example h4 { margin: 0 0 10px; font-size: 15px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--accent); }

/* Tables */
.table-wrap { overflow-x: auto; margin: 22px 0; }
table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--border); }
th { color: var(--text-muted); font-weight: 700; font-size: 13px; text-transform: uppercase; letter-spacing: 0.03em; }
tbody tr:hover { background: var(--surface-2); }
code:not(.hljs) { font-family: var(--mono); font-size: 0.9em; background: var(--surface-2); border: 1px solid var(--border); padding: 1px 6px; border-radius: 5px; }

/* TOC */
.toc { position: sticky; top: 82px; font-size: 14px; }
.toc .toc-title { font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 10px; }
.toc ul { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--border); }
.toc a { display: block; color: var(--text-secondary); padding: 5px 0 5px 14px; margin-left: -1px; border-left: 2px solid transparent; }
.toc a:hover, .toc a.active { color: var(--accent); border-left-color: var(--accent); text-decoration: none; }

/* Related / next */
.related { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin-top: 20px; }

/* Glossary */
.glossary-nav { display: flex; flex-wrap: wrap; gap: 6px; margin: 20px 0 30px; }
.glossary-nav a { font-family: var(--mono); font-weight: 700; width: 34px; height: 34px; display: grid; place-items: center; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text-secondary); }
.glossary-nav a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.term { border-bottom: 1px solid var(--border); padding: 22px 0; scroll-margin-top: 80px; }
.term dt { font-size: 20px; font-weight: 800; letter-spacing: -0.01em; margin-bottom: 6px; }
.term dt .en { color: var(--text-muted); font-weight: 500; font-size: 15px; }
.term dd { margin: 0; color: var(--text-secondary); font-size: 16px; }
.term dd a { text-decoration: underline; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--surface); margin-top: 40px; }
.site-footer .container { padding-top: 40px; padding-bottom: 40px; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 30px; }
@media (max-width: 700px) { .foot-grid { grid-template-columns: 1fr; } .doc-wrap { gap: 0; } }
.site-footer h4 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-muted); margin: 0 0 12px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin: 7px 0; }
.site-footer a { color: var(--text-secondary); font-size: 14.5px; }
.site-footer a:hover { color: var(--accent); }
.foot-bottom { border-top: 1px solid var(--border); margin-top: 30px; padding-top: 20px; color: var(--text-muted); font-size: 13px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.disclaimer { color: var(--text-muted); font-size: 12.5px; margin-top: 14px; line-height: 1.6; }

.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 16px; top: 10px; background: var(--accent); color: #fff; padding: 8px 14px; border-radius: 8px; z-index: 100; }