/* =========================================================================
   Clinical Data Pipeline & EDC Sync Hub — design system
   Light, professional clinical palette (teal / sky / indigo accents)
   ========================================================================= */

:root {
  /* Brand + accents */
  --c-primary: #0f766e;        /* teal-700 */
  --c-primary-600: #0d9488;
  --c-primary-400: #2dd4bf;
  --c-accent-1: #0d9488;       /* pipelines  - teal  */
  --c-accent-2: #2563eb;       /* standards  - blue  */
  --c-accent-3: #4f46e5;       /* queries    - indigo*/

  /* Neutrals */
  --c-bg: #f5f8f9;
  --c-bg-tint: #eef4f5;
  --c-surface: #ffffff;
  --c-surface-2: #f8fafc;
  --c-border: #e2e8f0;
  --c-border-strong: #cbd5e1;
  --c-text: #0f172a;
  --c-text-muted: #475569;
  --c-text-subtle: #64748b;
  --c-link: #0e7490;
  --c-link-hover: #0f766e;

  /* Code surface */
  --c-code-bg: #f6f9fb;
  --c-code-border: #e1e9ef;
  --c-inline-code-bg: #ecf3f4;
  --c-inline-code-fg: #0f766e;

  /* Layout */
  --container: 1280px;
  --content: 1120px;
  --narrow: 800px;
  --header-h: 64px;
  --radius: 14px;
  --radius-sm: 9px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 3px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 6px 20px -6px rgba(15, 23, 42, 0.16);
  --shadow-lg: 0 20px 45px -18px rgba(15, 23, 42, 0.30);
  --ring: 0 0 0 3px rgba(13, 148, 136, 0.35);

  --font-sans: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Cascadia Code", "Fira Code", Consolas, "Liberation Mono", Menlo, monospace;

  --transition: 180ms cubic-bezier(0.4, 0, 0.2, 1);
}

@media (min-width: 1024px) {
  :root { --header-h: 74px; }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 1.25rem);
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
  font-size: clamp(1rem, 0.96rem + 0.2vw, 1.075rem);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  /* sticky footer */
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

img, svg { max-width: 100%; }
img { height: auto; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1rem, 3vw, 2.25rem);
}
.narrow { max-width: var(--narrow); margin-inline: auto; }

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -3rem;
  z-index: 1000;
  background: var(--c-primary);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  transition: top var(--transition);
}
.skip-link:focus { top: 0.75rem; }

/* ---------- Icons ---------- */
.icon {
  width: 1.25em;
  height: 1.25em;
  flex: none;
  display: inline-block;
  vertical-align: -0.18em;
}

/* ---------- Links ---------- */
a { color: var(--c-link); text-decoration: none; }
a:hover { color: var(--c-link-hover); }
:focus-visible { outline: none; box-shadow: var(--ring); border-radius: 4px; }

/* =========================================================================
   Header
   ========================================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--c-border);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: var(--header-h);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--c-text);
  font-weight: 700;
  margin-right: auto;
}
.brand-mark { display: block; transition: transform var(--transition); }
.brand:hover .brand-mark { transform: rotate(-6deg) scale(1.05); }
.brand-text { display: flex; flex-direction: column; line-height: 1.12; }
.brand-title { font-size: 1.02rem; letter-spacing: -0.01em; }
.brand-sub {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--c-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.primary-nav ul {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
}
.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 0.85rem;
  border-radius: 999px;
  color: var(--c-text-muted);
  font-weight: 600;
  font-size: 0.94rem;
  border: 1px solid transparent;
  transition: color var(--transition), background var(--transition), border-color var(--transition), transform var(--transition);
}
.nav-link .icon { color: var(--nav-accent, var(--c-primary)); transition: transform var(--transition); }
.nav-link:hover {
  color: var(--c-text);
  background: var(--c-bg-tint);
  transform: translateY(-1px);
}
.nav-link:hover .icon { transform: scale(1.12); }
.nav-link.is-active {
  color: var(--c-text);
  background: color-mix(in srgb, var(--nav-accent, var(--c-primary)) 12%, white);
  border-color: color-mix(in srgb, var(--nav-accent, var(--c-primary)) 32%, white);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--c-border);
  background: var(--c-surface);
  border-radius: var(--radius-sm);
  color: var(--c-text);
  cursor: pointer;
}
.nav-toggle .icon { width: 1.5em; height: 1.5em; }
.nav-toggle-close { display: none; }

@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--c-surface);
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--shadow-md);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition);
  }
  .primary-nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
    padding: 0.75rem clamp(1rem, 3vw, 2.25rem) 1.1rem;
  }
  .nav-link { font-size: 1rem; padding: 0.7rem 0.85rem; }
  body.nav-open .primary-nav { max-height: 70vh; }
  body.nav-open .nav-toggle-open { display: none; }
  body.nav-open .nav-toggle-close { display: block; }
}

/* =========================================================================
   Main / footer scaffold
   ========================================================================= */
.site-main { flex: 1 0 auto; }

.site-footer {
  flex-shrink: 0;
  margin-top: 4rem;
  background: #0b2530;
  color: #cbd5e1;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 2.5rem;
  padding-block: 2.75rem;
}
.footer-brand { display: flex; gap: 1rem; align-items: flex-start; }
.footer-mark { border-radius: 12px; }
.footer-name { margin: 0 0 0.35rem; font-weight: 700; color: #f1f5f9; }
.footer-tagline { margin: 0; font-size: 0.92rem; color: #94a3b8; max-width: 52ch; }
.footer-heading {
  margin: 0 0 0.75rem;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #5eead4;
}
.footer-nav ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.5rem; }
.footer-nav a { color: #cbd5e1; font-weight: 500; }
.footer-nav a:hover { color: #fff; text-decoration: underline; text-underline-offset: 3px; }
.footer-bar {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-block: 1rem;
  font-size: 0.85rem;
  color: #94a3b8;
}
.footer-bar p { margin: 0; }

@media (max-width: 720px) {
  .footer-inner { grid-template-columns: 1fr; gap: 1.75rem; }
}

/* =========================================================================
   Homepage
   ========================================================================= */
.hero {
  background:
    radial-gradient(1200px 500px at 15% -10%, rgba(13, 148, 136, 0.12), transparent 60%),
    radial-gradient(1000px 460px at 100% 0%, rgba(37, 99, 235, 0.12), transparent 55%),
    linear-gradient(180deg, #ffffff, var(--c-bg));
  border-bottom: 1px solid var(--c-border);
}
.hero-inner { padding-block: clamp(2.75rem, 6vw, 5rem); }
.hero-logo { display: block; width: clamp(240px, 38vw, 360px); height: auto; margin-bottom: 1.75rem; }
.hero-title {
  font-size: clamp(2rem, 1.3rem + 3.2vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.025em;
  margin: 0 0 1rem;
  max-width: 18ch;
  overflow-wrap: break-word;
  padding-bottom: 0.05em;
  background: linear-gradient(120deg, #0f766e, #2563eb 55%, #4f46e5);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-lead {
  font-size: clamp(1.05rem, 1rem + 0.4vw, 1.3rem);
  color: var(--c-text-muted);
  max-width: 60ch;
  margin: 0 0 2rem;
}

.hero-ctas { display: grid; gap: 1rem; grid-template-columns: repeat(3, 1fr); }
@media (max-width: 900px) { .hero-ctas { grid-template-columns: 1fr; } }

.cta {
  --cta: var(--c-primary);
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1.1rem 1.15rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  color: var(--c-text);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.cta:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: color-mix(in srgb, var(--cta) 40%, var(--c-border));
  color: var(--c-text);
}
.cta-icon {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  flex: none;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(135deg, color-mix(in srgb, var(--cta) 86%, white), var(--cta));
  box-shadow: 0 6px 16px -6px color-mix(in srgb, var(--cta) 70%, transparent);
}
.cta-icon .icon { width: 1.6em; height: 1.6em; }
.cta-text { display: flex; flex-direction: column; gap: 0.15rem; min-width: 0; }
.cta-text strong { font-size: 1.02rem; }
.cta-text small { color: var(--c-text-subtle); font-size: 0.84rem; line-height: 1.45;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.cta-arrow { margin-left: auto; color: var(--cta); transition: transform var(--transition); }
.cta:hover .cta-arrow { transform: translateX(4px); }

.intro { padding-block: clamp(2.5rem, 5vw, 4rem); }
/* Left-aligned to match the hero/pillars edge; readable measure, not a small centered box. */
.intro .section-heading { max-width: 24ch; }
.intro p { max-width: 90ch; }
.section-heading {
  font-size: clamp(1.5rem, 1.2rem + 1vw, 2rem);
  letter-spacing: -0.02em;
  margin: 0 0 1.25rem;
}
.intro p { color: var(--c-text-muted); margin: 0 0 1.1rem; }
.intro strong { color: var(--c-text); }

.pillars { padding-block: clamp(1rem, 3vw, 2rem) clamp(2.5rem, 5vw, 4rem); }
.pillar-grid { display: grid; gap: 1.5rem; grid-template-columns: repeat(3, 1fr); }
@media (max-width: 1000px) { .pillar-grid { grid-template-columns: 1fr; } }

.pillar-card {
  --card: var(--c-primary);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-top: 4px solid var(--card);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition), box-shadow var(--transition);
}
.pillar-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.pillar-head { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; }
.pillar-icon {
  display: grid; place-items: center;
  width: 44px; height: 44px; flex: none;
  border-radius: 11px;
  color: var(--card);
  background: color-mix(in srgb, var(--card) 12%, white);
}
.pillar-icon .icon { width: 1.5em; height: 1.5em; }
.pillar-title { margin: 0; font-size: 1.18rem; letter-spacing: -0.01em; }
.pillar-title a { color: var(--c-text); }
.pillar-title a:hover { color: var(--card); }
.pillar-blurb { color: var(--c-text-muted); font-size: 0.95rem; margin: 0 0 1rem; }
.pillar-topics { list-style: none; margin: 0 0 1.1rem; padding: 0; display: grid; gap: 0.3rem; }
.pillar-topics a {
  display: flex; align-items: center; gap: 0.3rem;
  color: var(--c-text-muted); font-weight: 500; font-size: 0.92rem;
  padding: 0.32rem 0.4rem; border-radius: 8px;
  transition: background var(--transition), color var(--transition);
}
.pillar-topics a:hover { background: var(--c-bg-tint); color: var(--card); }
.topic-chevron { width: 1em; height: 1em; color: var(--card); }
.pillar-more {
  margin-top: auto;
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-weight: 600; color: var(--card);
}
.pillar-more .more-arrow { transition: transform var(--transition); }
.pillar-more:hover .more-arrow { transform: translateX(4px); }

/* =========================================================================
   Content page layout
   ========================================================================= */
.page-layout { padding-block: 1.5rem 3rem; }
/* Content pages span the same width as the header/footer container. */
.page { max-width: none; }

/* Breadcrumbs */
.breadcrumbs { margin-bottom: 1.5rem; }
.breadcrumbs ol {
  list-style: none; display: flex; flex-wrap: wrap; align-items: center;
  gap: 0.25rem 0.4rem; margin: 0; padding: 0;
  font-size: 0.86rem;
}
.crumb { display: inline-flex; align-items: center; gap: 0.4rem; min-width: 0; }
.crumb a { color: var(--c-text-subtle); font-weight: 500; }
.crumb a:hover { color: var(--c-primary); }
.crumb span[aria-current] { color: var(--c-text); font-weight: 600; }
.crumb-sep { width: 0.9em; height: 0.9em; color: var(--c-border-strong); }
.breadcrumbs li:last-child .crumb-sep { display: none; }

/* =========================================================================
   Prose / typography
   ========================================================================= */
.prose { font-size: 1.05rem; }
.prose > * + * { margin-top: 1.15rem; }

.prose h1 {
  font-size: clamp(1.85rem, 1.4rem + 2vw, 2.85rem);
  line-height: 1.12;
  letter-spacing: -0.025em;
  margin: 0 0 1.25rem;
  overflow-wrap: break-word;
  padding-bottom: 0.05em;
  background: linear-gradient(120deg, #0f766e, #2563eb 60%, #4f46e5);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.prose h2 {
  font-size: clamp(1.4rem, 1.2rem + 0.9vw, 1.85rem);
  letter-spacing: -0.015em;
  margin-top: 2.6rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--c-border);
}
.prose h3 { font-size: clamp(1.18rem, 1.05rem + 0.5vw, 1.4rem); margin-top: 2rem; }
.prose h4 { font-size: 1.1rem; margin-top: 1.6rem; }
.prose h1, .prose h2, .prose h3, .prose h4 { scroll-margin-top: calc(var(--header-h) + 1.25rem); }
.prose h2, .prose h3, .prose h4 { position: relative; }

.heading-anchor {
  opacity: 0;
  margin-left: 0.4rem;
  color: var(--c-primary);
  font-weight: 600;
  text-decoration: none;
  transition: opacity var(--transition);
}
.prose h2:hover .heading-anchor,
.prose h3:hover .heading-anchor,
.prose h4:hover .heading-anchor,
.heading-anchor:focus { opacity: 0.85; }

.prose p { color: var(--c-text); }
.prose strong { color: var(--c-text); font-weight: 700; }

.prose a {
  color: var(--c-link);
  font-weight: 500;
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--c-link) 35%, transparent);
  text-underline-offset: 2px;
  transition: color var(--transition), text-decoration-color var(--transition), background var(--transition);
  border-radius: 3px;
}
.prose a:hover {
  color: var(--c-link-hover);
  text-decoration-color: currentColor;
  background: rgba(13, 148, 136, 0.07);
}

.prose ul, .prose ol { padding-left: 1.4rem; }
.prose li + li { margin-top: 0.4rem; }
.prose ul > li::marker { color: var(--c-primary); }
.prose ol > li::marker { color: var(--c-text-subtle); font-weight: 600; }

.prose blockquote {
  margin: 1.4rem 0;
  padding: 0.6rem 1.2rem;
  border-left: 4px solid var(--c-primary-400);
  background: var(--c-bg-tint);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--c-text-muted);
}
.prose hr { border: none; border-top: 1px solid var(--c-border); margin: 2.5rem 0; }

/* Inline code */
.prose :not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--c-inline-code-bg);
  color: var(--c-inline-code-fg);
  padding: 0.12em 0.42em;
  border-radius: 6px;
  border: none;
  white-space: break-spaces;
}

/* =========================================================================
   Code blocks
   ========================================================================= */
.code-block {
  position: relative;
  margin-block: 1.5rem;
  border: 1px solid var(--c-code-border);
  border-radius: var(--radius);
  background: var(--c-code-bg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.code-block::before {
  content: attr(data-lang);
  position: absolute;
  top: 0; left: 0;
  font: 600 0.7rem/1 var(--font-sans);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-text-subtle);
  background: color-mix(in srgb, var(--c-primary) 8%, white);
  border-bottom-right-radius: 10px;
  padding: 0.45rem 0.7rem;
}
.code-block pre {
  margin: 0;
  padding: 2.4rem 1.15rem 1.15rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  tab-size: 4;
  color: #1e293b;
}
.code-block pre code { font-family: inherit; background: none; padding: 0; }

.code-copy {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font: 600 0.78rem/1 var(--font-sans);
  color: var(--c-text-muted);
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 8px;
  padding: 0.4rem 0.6rem;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition), color var(--transition), border-color var(--transition), background var(--transition);
}
.code-block:hover .code-copy,
.code-copy:focus-visible { opacity: 1; }
.code-copy:hover { color: var(--c-primary); border-color: var(--c-primary-400); }
.code-copy.is-copied { color: #047857; border-color: #6ee7b7; background: #ecfdf5; }
@media (hover: none) { .code-copy { opacity: 1; } }

/* Prism light theme (palette-matched) */
.token.comment, .token.prolog, .token.doctype, .token.cdata { color: #64748b; font-style: italic; }
.token.punctuation { color: #475569; }
.token.property, .token.tag, .token.constant, .token.symbol, .token.deleted { color: #be123c; }
.token.boolean, .token.number { color: #b45309; }
.token.selector, .token.attr-name, .token.string, .token.char, .token.builtin, .token.inserted { color: #047857; }
.token.operator, .token.entity, .token.url { color: #0e7490; }
.token.atrule, .token.attr-value, .token.keyword { color: #2563eb; }
.token.function, .token.class-name { color: #4f46e5; }
.token.regex, .token.important, .token.variable { color: #c026d3; }
.token.important, .token.bold { font-weight: 700; }
.token.italic { font-style: italic; }

/* =========================================================================
   Tables
   ========================================================================= */
.table-wrap {
  overflow-x: auto;
  margin-block: 1.5rem;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  -webkit-overflow-scrolling: touch;
}
.table-wrap table { width: 100%; border-collapse: collapse; min-width: 480px; font-size: 0.95rem; }
.table-wrap th, .table-wrap td { padding: 0.75rem 1rem; text-align: left; border-bottom: 1px solid var(--c-border); }
.table-wrap thead th {
  background: color-mix(in srgb, var(--c-primary) 9%, white);
  color: var(--c-text);
  font-weight: 700;
  white-space: nowrap;
}
.table-wrap tbody tr { transition: background var(--transition); }
.table-wrap tbody tr:hover { background: var(--c-surface-2); }
.table-wrap tbody tr:last-child td { border-bottom: none; }

/* =========================================================================
   Task list checkboxes
   ========================================================================= */
.prose ul.contains-task-list { list-style: none; padding-left: 0.2rem; }
.prose ul.contains-task-list ul.contains-task-list { padding-left: 1.4rem; }
.task-list-item {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 0.15rem 0;
}
.task-list-item::marker { content: ""; }
.task-list-item-checkbox {
  appearance: none;
  -webkit-appearance: none;
  flex: none;
  width: 1.2em;
  height: 1.2em;
  margin-top: 0.28em;
  border: 2px solid var(--c-border-strong);
  border-radius: 5px;
  background: var(--c-surface);
  cursor: pointer;
  display: grid;
  place-content: center;
  transition: background var(--transition), border-color var(--transition);
}
.task-list-item-checkbox::after {
  content: "";
  width: 0.6em;
  height: 0.6em;
  transform: scale(0);
  transform-origin: center;
  transition: transform var(--transition);
  box-shadow: inset 1em 1em #fff;
  clip-path: polygon(14% 44%, 0 60%, 40% 100%, 100% 18%, 86% 4%, 40% 72%);
}
.task-list-item-checkbox:checked {
  background: var(--c-primary);
  border-color: var(--c-primary);
}
.task-list-item-checkbox:checked::after { transform: scale(1); }
.task-list-item-checkbox:hover { border-color: var(--c-primary); }
.task-list-item.is-done { color: var(--c-text-subtle); text-decoration: line-through; }

/* =========================================================================
   FAQ accordions (also styles any <details>)
   ========================================================================= */
.faq { margin-block: 1.5rem; display: grid; gap: 0.75rem; }
details.accordion, .prose details {
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  background: var(--c-surface);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
details.accordion > summary, .prose details > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.95rem 1.1rem;
  font-weight: 600;
  color: var(--c-text);
  background: var(--c-surface);
  transition: background var(--transition);
}
details.accordion > summary::-webkit-details-marker,
.prose details > summary::-webkit-details-marker { display: none; }
details.accordion > summary::before, .prose details > summary::before {
  content: "";
  width: 0.6em; height: 0.6em;
  border-right: 2px solid var(--c-primary);
  border-bottom: 2px solid var(--c-primary);
  transform: rotate(-45deg);
  transition: transform var(--transition);
  flex: none;
}
details.accordion[open] > summary::before, .prose details[open] > summary::before { transform: rotate(45deg); }
details.accordion > summary:hover, .prose details > summary:hover { background: var(--c-bg-tint); }
details.accordion > .accordion-body, .prose details > :not(summary) {
  padding: 0 1.1rem 1.1rem;
  color: var(--c-text-muted);
}

/* =========================================================================
   Mermaid + KaTeX
   ========================================================================= */
.mermaid-wrap {
  margin-block: 1.5rem;
  padding: 1.25rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow-x: auto;
  text-align: center;
}
.mermaid { visibility: hidden; }
.mermaid[data-processed="true"] { visibility: visible; }
.katex-display { overflow-x: auto; overflow-y: hidden; padding-block: 0.4rem; }

/* =========================================================================
   Related navigation
   ========================================================================= */
.related {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--c-border);
  display: grid;
  gap: 2rem;
}
.related-title {
  display: flex; align-items: center; gap: 0.5rem;
  font-size: 1.15rem; margin: 0 0 1rem;
}
.related-title .icon { color: var(--c-primary); }
.related-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.75rem; }
.related-list--compact { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.related-list a {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.15rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.related-list a:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--c-primary-400);
}
.related-link-title { font-weight: 600; color: var(--c-text); }
.related-list a:hover .related-link-title { color: var(--c-primary); }
.related-link-desc { font-size: 0.88rem; color: var(--c-text-subtle); line-height: 1.5;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* Wide screens: give related-children two columns */
@media (min-width: 1024px) {
  .related-group:first-child .related-list:not(.related-list--compact) {
    grid-template-columns: repeat(2, 1fr);
  }
}