/* =========================================================================
   Closed Captioning Org — Design System
   Light, professional, broadcast-themed palette.
   ========================================================================= */

:root {
  /* Brand palette — broadcast blue + captioning highlight + signal accents */
  --color-brand: #1e40af;
  --color-brand-strong: #1e3a8a;
  --color-brand-soft: #dbeafe;
  --color-accent: #0d9488;       /* teal — parsing */
  --color-accent-soft: #ccfbf1;
  --color-magenta: #db2777;       /* QC / compliance */
  --color-magenta-soft: #fce7f3;
  --color-amber: #d97706;
  --color-amber-soft: #fef3c7;
  --color-violet: #7c3aed;
  --color-violet-soft: #ede9fe;

  /* Neutrals */
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-alt: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-text-subtle: #64748b;

  /* Semantic */
  --color-code-bg: #f8fafc;
  --color-inline-code-bg: #eef2ff;
  --color-inline-code-text: #3730a3;

  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --font-display: "Inter", system-ui, sans-serif;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Layout */
  --header-height: 4.25rem;
  --max-width: 1480px;
  --content-max-width: 1180px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 22px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 14px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 18px 40px rgba(15, 23, 42, 0.10);

  /* Transitions */
  --t-fast: 120ms ease;
  --t-base: 200ms ease;
  --t-slow: 360ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

/* ---------- Base ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--color-text);
  background:
    radial-gradient(1200px 600px at 110% -10%, rgba(13, 148, 136, 0.06), transparent 60%),
    radial-gradient(1000px 500px at -10% 0%, rgba(30, 64, 175, 0.06), transparent 60%),
    var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Default-size inline SVG icons so they never balloon to container width
   when authors forget explicit width/height attrs. Components that need
   a different size override locally. */
svg {
  width: 1.25em;
  height: 1.25em;
  flex-shrink: 0;
  vertical-align: middle;
  display: inline-block;
}

/* Block-level imagery / logos opt back into block layout */
.brand__logo,
.hero__visual svg,
img.brand__logo {
  display: block;
}

.hero__visual svg {
  width: 100%;
  height: 100%;
}

a {
  color: var(--color-brand);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast), background-color var(--t-fast);
}

a:hover,
a:focus-visible {
  color: var(--color-brand-strong);
  border-bottom-color: var(--color-brand);
}

a.external-link::after {
  content: "↗";
  display: inline-block;
  margin-left: 0.15em;
  font-size: 0.85em;
  color: var(--color-text-subtle);
  transform: translateY(-1px);
}

:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Anchor offset for sticky header */
:target,
h1[id],
h2[id],
h3[id],
h4[id],
h5[id],
h6[id] {
  scroll-margin-top: calc(var(--header-height) + 1rem);
}

/* ---------- Layout primitives ---------- */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding-inline: clamp(1rem, 3vw, 2.5rem);
}

.site-main {
  flex: 1 0 auto;
  padding-block: clamp(1.5rem, 3vw, 3rem);
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  display: flex;
  align-items: center;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding-inline: clamp(1rem, 3vw, 2.5rem);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  color: var(--color-text);
  border: none;
  letter-spacing: -0.01em;
}

.brand__logo {
  width: 38px;
  height: 38px;
}

.brand__name {
  font-size: 1.02rem;
  line-height: 1.1;
}

.brand__name strong {
  color: var(--color-brand);
}

.brand:hover .brand__logo,
.brand:focus-visible .brand__logo {
  transform: rotate(-4deg) scale(1.04);
}
.brand__logo {
  transition: transform var(--t-base);
}

/* Primary nav */
.nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.85rem;
  border-radius: 999px;
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  border: none;
  position: relative;
}

.nav__link svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.nav__link:hover,
.nav__link:focus-visible {
  background: var(--color-surface-alt);
  color: var(--color-text);
}

.nav__link[aria-current="page"],
.nav__link.is-active {
  background: var(--color-brand-soft);
  color: var(--color-brand-strong);
}

.nav__link[aria-current="page"]::after,
.nav__link.is-active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -10px;
  transform: translateX(-50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-brand);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.45rem 0.6rem;
  cursor: pointer;
  color: var(--color-text);
}
.nav-toggle svg {
  width: 22px;
  height: 22px;
}

@media (max-width: 880px) {
  .nav {
    position: fixed;
    inset: var(--header-height) 0 auto 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.5rem 1rem 1rem;
    transform: translateY(-110%);
    transition: transform var(--t-slow);
    box-shadow: var(--shadow-md);
  }
  .nav.is-open {
    transform: translateY(0);
  }
  .nav__link {
    border-radius: 12px;
    padding: 0.85rem 1rem;
    font-size: 1rem;
  }
  .nav__link[aria-current="page"]::after,
  .nav__link.is-active::after {
    display: none;
  }
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  .brand__name {
    font-size: 0.95rem;
  }
}

/* ---------- Footer ---------- */

.site-footer {
  flex-shrink: 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-16);
  padding-block: var(--space-10) var(--space-8);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-8);
}

@media (max-width: 880px) {
  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
}

.site-footer__brand p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-top: 0.75rem;
  max-width: 38ch;
}

.site-footer__col h4 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-subtle);
  margin: 0 0 var(--space-3) 0;
}

.site-footer__col ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.45rem;
}

.site-footer__col a {
  color: var(--color-text);
  border: none;
  font-size: 0.95rem;
}

.site-footer__col a:hover {
  color: var(--color-brand);
}

.site-footer__bottom {
  margin-top: var(--space-8);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--color-text-subtle);
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* ---------- Home / hero ---------- */

.hero {
  position: relative;
  padding-block: clamp(2rem, 6vw, 5rem) clamp(2rem, 5vw, 4rem);
  overflow: hidden;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

@media (max-width: 980px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: left;
  }
  .hero__visual {
    order: -1;
    max-width: 260px;
    margin: 0 auto;
  }
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-brand-soft);
  color: var(--color-brand-strong);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  margin-bottom: var(--space-5);
}

.hero__eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-brand);
  box-shadow: 0 0 0 4px rgba(30, 64, 175, 0.15);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw + 1rem, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.025em;
  margin: 0 0 var(--space-5) 0;
  color: var(--color-text);
}

.hero h1 .grad {
  background: linear-gradient(120deg, var(--color-brand) 0%, var(--color-accent) 55%, var(--color-magenta) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-4) 0;
  max-width: 62ch;
}

.hero__ctas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.8rem 1.1rem;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.98rem;
  border: 1px solid transparent;
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-fast), box-shadow var(--t-base), border-color var(--t-fast),
    background-color var(--t-fast), color var(--t-fast);
}

.cta__icon {
  width: 26px;
  height: 26px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  flex-shrink: 0;
}

.cta__icon svg {
  width: 18px;
  height: 18px;
}

.cta:hover,
.cta:focus-visible {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

.cta--brand {
  background: var(--color-brand);
  color: white;
}
.cta--brand:hover,
.cta--brand:focus-visible {
  background: var(--color-brand-strong);
  color: white;
}
.cta--brand .cta__icon {
  background: rgba(255, 255, 255, 0.18);
  color: white;
}

.cta--accent .cta__icon {
  background: var(--color-accent-soft);
  color: var(--color-accent);
}
.cta--magenta .cta__icon {
  background: var(--color-magenta-soft);
  color: var(--color-magenta);
}
.cta--brand-soft .cta__icon {
  background: var(--color-brand-soft);
  color: var(--color-brand);
}

/* Hero big visual */
.hero__visual {
  position: relative;
  aspect-ratio: 1;
  width: min(420px, 100%);
  margin-left: auto;
}

.hero__visual svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 22px 50px rgba(30, 64, 175, 0.18));
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@media (prefers-reduced-motion: reduce) {
  .hero__visual svg { animation: none; }
}

/* ---------- Section grid (home) ---------- */

.sections {
  padding-block: clamp(2rem, 4vw, 4rem);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-6);
  margin-bottom: var(--space-8);
  flex-wrap: wrap;
}

.section-head h2 {
  font-size: clamp(1.6rem, 2vw + 1rem, 2.2rem);
  letter-spacing: -0.02em;
  margin: 0;
}

.section-head p {
  color: var(--color-text-muted);
  max-width: 50ch;
  margin: 0;
}

.section-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-6);
}

.section-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  background: var(--color-surface);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-base), box-shadow var(--t-base), border-color var(--t-base);
  position: relative;
  overflow: hidden;
  color: var(--color-text);
  text-decoration: none;
}

.section-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--card-color, var(--color-brand)) 0%, transparent 55%);
  opacity: 0.05;
  pointer-events: none;
  transition: opacity var(--t-base);
}

.section-card:hover,
.section-card:focus-visible {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--card-color, var(--color-brand));
  border-bottom: 1px solid var(--card-color, var(--color-brand));
}
.section-card:hover::before {
  opacity: 0.12;
}

.section-card__icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: color-mix(in oklab, var(--card-color, var(--color-brand)) 14%, white);
  color: var(--card-color, var(--color-brand));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-3);
}

.section-card__icon svg {
  width: 26px;
  height: 26px;
}

.section-card h3 {
  margin: 0;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

.section-card p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.97rem;
}

.section-card__arrow {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--card-color, var(--color-brand));
}

.section-card__arrow svg {
  width: 18px;
  height: 18px;
  transition: transform var(--t-base);
}

.section-card:hover .section-card__arrow svg {
  transform: translateX(4px);
}

/* ---------- Content / article ---------- */

.content-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: clamp(2rem, 4vw, 4rem);
  align-items: flex-start;
}

@media (max-width: 1100px) {
  .content-wrap {
    grid-template-columns: 1fr;
  }
  .toc {
    display: none;
  }
}

.article {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: clamp(1.5rem, 3vw, 3rem);
  box-shadow: var(--shadow-sm);
  max-width: var(--content-max-width);
  width: 100%;
}

.article h1 {
  font-size: clamp(1.8rem, 2.5vw + 1rem, 2.8rem);
  letter-spacing: -0.025em;
  margin: 0 0 var(--space-6) 0;
  background: linear-gradient(120deg, var(--section-color, var(--color-brand)) 0%, var(--color-accent) 70%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.article h2 {
  font-size: clamp(1.35rem, 1vw + 1rem, 1.7rem);
  letter-spacing: -0.015em;
  margin: var(--space-10) 0 var(--space-4) 0;
  color: var(--color-text);
  position: relative;
  padding-left: 0.85rem;
}

.article h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45em;
  bottom: 0.45em;
  width: 4px;
  border-radius: 3px;
  background: var(--section-color, var(--color-brand));
}

.article h3 {
  font-size: 1.2rem;
  margin: var(--space-8) 0 var(--space-3) 0;
  color: var(--color-text);
}

.article p {
  margin: 0 0 var(--space-4) 0;
  color: var(--color-text);
}

.article ul,
.article ol {
  padding-left: 1.4rem;
  margin: 0 0 var(--space-5) 0;
}

.article li {
  margin-bottom: 0.4rem;
}

.article strong {
  color: var(--color-text);
}

.article a {
  border-bottom: 1px solid color-mix(in oklab, var(--color-brand) 25%, transparent);
}
.article a:hover {
  background: var(--color-brand-soft);
  border-bottom-color: var(--color-brand);
}

/* Section-color tint per top-level area */
[data-section="broadcast-captioning-architecture-compliance"] {
  --section-color: var(--color-brand);
  --section-color-soft: var(--color-brand-soft);
}
[data-section="srt-scc-webvtt-parsing-workflows"] {
  --section-color: var(--color-accent);
  --section-color-soft: var(--color-accent-soft);
}
[data-section="automated-qc-validation-reporting"] {
  --section-color: var(--color-magenta);
  --section-color-soft: var(--color-magenta-soft);
}

/* ---------- Breadcrumbs ---------- */

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.55rem;
  font-size: 0.88rem;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-5);
  align-items: center;
}

.breadcrumbs a {
  color: var(--color-text-muted);
  border: none;
}

.breadcrumbs a:hover {
  color: var(--color-brand);
}

.breadcrumbs__sep {
  color: var(--color-border-strong);
}

.breadcrumbs__current {
  color: var(--color-text);
  font-weight: 500;
}

/* ---------- Inline code ---------- */

:not(pre) > code {
  font-family: var(--font-mono);
  background: var(--color-inline-code-bg);
  color: var(--color-inline-code-text);
  padding: 0.12em 0.42em;
  border-radius: 5px;
  font-size: 0.92em;
  border: none;
  white-space: nowrap;
}

/* ---------- Code blocks ---------- */

.codeblock {
  position: relative;
  margin: var(--space-5) 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-code-bg);
  overflow: hidden;
}

.codeblock__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.4rem 0.7rem 0.4rem 1rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
  background: var(--color-surface-alt);
  border-bottom: 1px solid var(--color-border);
}

.codeblock__lang {
  font-weight: 600;
}

.codeblock__copy {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: 6px;
  padding: 0.25rem 0.55rem;
  font-size: 0.75rem;
  font-family: var(--font-sans);
  text-transform: none;
  letter-spacing: normal;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: background-color var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}

.codeblock__copy svg {
  width: 13px;
  height: 13px;
}

.codeblock__copy:hover {
  border-color: var(--color-brand);
  color: var(--color-brand);
}

.codeblock__copy.is-copied {
  background: var(--color-brand-soft);
  color: var(--color-brand-strong);
  border-color: transparent;
}

pre[class*="language-"] {
  margin: 0;
  padding: 1rem 1.1rem;
  background: var(--color-code-bg);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.55;
  overflow-x: auto;
  color: var(--color-text);
}

pre code[class*="language-"] {
  font-family: inherit;
  background: none;
  padding: 0;
  border-radius: 0;
  white-space: pre;
  color: inherit;
}

/* Light syntax theme matching the site palette */
.token.comment,
.token.prolog,
.token.doctype,
.token.cdata {
  color: #64748b;
  font-style: italic;
}

.token.punctuation { color: #475569; }
.token.namespace { opacity: 0.7; }

.token.property,
.token.tag,
.token.boolean,
.token.number,
.token.constant,
.token.symbol,
.token.deleted {
  color: #b45309;
}

.token.selector,
.token.attr-name,
.token.string,
.token.char,
.token.builtin,
.token.inserted {
  color: #0d9488;
}

.token.operator,
.token.entity,
.token.url,
.language-css .token.string,
.style .token.string {
  color: #1e40af;
}

.token.atrule,
.token.attr-value,
.token.keyword {
  color: #7c3aed;
}

.token.function,
.token.class-name {
  color: #db2777;
}

.token.regex,
.token.important,
.token.variable {
  color: #d97706;
}

.token.important,
.token.bold { font-weight: 700; }
.token.italic { font-style: italic; }
.token.entity { cursor: help; }

/* ---------- Tables ---------- */

.table-scroll {
  overflow-x: auto;
  margin: var(--space-5) 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.article table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  min-width: 540px;
}

.article th,
.article td {
  padding: 0.7rem 0.95rem;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

.article th {
  background: var(--color-surface-alt);
  font-weight: 600;
  color: var(--color-text);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.article tbody tr:last-child td {
  border-bottom: none;
}

.article tbody tr:hover {
  background: color-mix(in oklab, var(--section-color, var(--color-brand)) 5%, white);
}

/* ---------- Task list checkboxes ---------- */

.article ul li.task-list-item,
.article ol li.task-list-item {
  list-style: none;
  margin-left: -1.4rem;
  padding-left: 0;
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
}

.article li.task-list-item input[type="checkbox"] {
  margin: 0.35em 0 0 0;
  width: 1.05rem;
  height: 1.05rem;
  accent-color: var(--section-color, var(--color-brand));
  cursor: pointer;
  flex-shrink: 0;
}

.article li.task-list-item.is-checked > * {
  text-decoration: line-through;
  color: var(--color-text-subtle);
}

/* ---------- FAQ accordions ---------- */

.faq {
  margin: var(--space-5) 0;
  display: grid;
  gap: 0.75rem;
}

.faq__item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  overflow: hidden;
  transition: border-color var(--t-base), box-shadow var(--t-base);
}

.faq__item[open] {
  border-color: var(--section-color, var(--color-brand));
  box-shadow: var(--shadow-sm);
}

.faq__summary {
  cursor: pointer;
  list-style: none;
  padding: 1rem 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.faq__summary::-webkit-details-marker { display: none; }

.faq__summary::after {
  content: "";
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  transform: rotate(45deg);
  transition: transform var(--t-base);
  flex-shrink: 0;
}

.faq__item[open] .faq__summary::after {
  transform: rotate(-135deg);
  border-color: var(--section-color, var(--color-brand));
}

.faq__body {
  padding: 0 1.1rem 1.1rem;
  color: var(--color-text-muted);
}

.faq__body > *:first-child { margin-top: 0; }
.faq__body > *:last-child { margin-bottom: 0; }

/* ---------- Related links ---------- */

.related {
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px dashed var(--color-border);
}

.related h2 {
  font-size: 1.1rem;
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 var(--space-4) 0;
  padding-left: 0;
}

.related h2::before { display: none; }

.related__list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-4);
}

.related__link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: var(--color-surface);
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all var(--t-base);
}
.related__link:hover {
  background: var(--color-brand-soft);
  border-color: var(--color-brand);
  color: var(--color-brand-strong);
  transform: translateX(2px);
}
.related__link svg {
  width: 18px;
  height: 18px;
  color: var(--section-color, var(--color-brand));
  flex-shrink: 0;
}

/* ---------- Mermaid container ---------- */

.mermaid-container {
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  margin: var(--space-5) 0;
  overflow-x: auto;
  text-align: center;
}

.mermaid-container svg {
  margin: 0 auto;
  max-width: 100%;
}

/* ---------- KaTeX adjustments ---------- */

.katex {
  font-size: 1.05em;
}

.katex-display {
  margin: var(--space-5) 0;
  padding: var(--space-4);
  background: var(--color-surface-alt);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  overflow-x: auto;
}

/* ---------- Blockquote ---------- */

.article blockquote {
  margin: var(--space-5) 0;
  padding: 0.6rem 1.1rem;
  border-left: 4px solid var(--section-color, var(--color-brand));
  background: var(--color-surface-alt);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* ---------- TOC ---------- */

.toc {
  position: sticky;
  top: calc(var(--header-height) + 1.5rem);
  align-self: start;
  font-size: 0.9rem;
}

.toc h2 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-subtle);
  margin: 0 0 var(--space-3) 0;
}

.toc ol {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.35rem;
  border-left: 1px solid var(--color-border);
}

.toc li a {
  display: block;
  padding: 0.3rem 0.8rem;
  color: var(--color-text-muted);
  border: none;
  border-left: 2px solid transparent;
  margin-left: -1px;
  font-weight: 500;
  transition: color var(--t-fast), border-color var(--t-fast);
}

.toc li a:hover,
.toc li a.is-active {
  color: var(--color-brand);
  border-left-color: var(--color-brand);
}

/* ---------- Section index pages ---------- */

.section-hero {
  padding-block: clamp(1.5rem, 3vw, 3rem) clamp(1rem, 2vw, 2rem);
}

.section-hero h1 {
  font-size: clamp(2rem, 2vw + 1.5rem, 3rem);
  letter-spacing: -0.025em;
  margin: 0 0 var(--space-3) 0;
  background: linear-gradient(120deg, var(--section-color, var(--color-brand)), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.subpage-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.subpage-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text);
  transition: all var(--t-base);
}

.subpage-card:hover {
  border-color: var(--section-color, var(--color-brand));
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.subpage-card__title {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--color-text);
}

.subpage-card__hint {
  font-size: 0.85rem;
  color: var(--color-text-subtle);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: auto;
  color: var(--section-color, var(--color-brand));
  font-weight: 500;
}
.subpage-card__hint svg {
  width: 16px;
  height: 16px;
  transition: transform var(--t-base);
}
.subpage-card:hover .subpage-card__hint svg {
  transform: translateX(3px);
}

/* ---------- Misc ---------- */

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* Skip-to-content link for keyboard / screen-reader users */
.skip-link {
  position: absolute;
  top: -100px;
  left: 12px;
  background: var(--color-brand);
  color: #fff;
  padding: 0.7rem 1.1rem;
  border-radius: 8px;
  font-weight: 600;
  z-index: 100;
  transition: top var(--t-base);
  border: none;
}
.skip-link:focus {
  top: 12px;
  color: #fff;
}

@media print {
  .site-header, .site-footer, .toc, .codeblock__copy { display: none; }
  .article { box-shadow: none; border: none; }
}