/* =========================================================================
   Clinical Trial Automation — design system
   Light, professional, clinical palette. Wide on desktop, elegant on mobile.
   ========================================================================= */
:root {
  /* Palette */
  --teal-900: #134e5e;
  --teal-800: #155e75;
  --teal-700: #0e7490;
  --teal-600: #0891b2;
  --teal-500: #06b6d4;
  --teal-50:  #ecfeff;
  --teal-100: #cffafe;

  --indigo-600: #4f46e5;
  --indigo-500: #6366f1;
  --violet-500: #8b5cf6;
  --emerald-500: #10b981;
  --amber-500: #f59e0b;
  --orange-500: #f97316;
  --rose-500: #f43f5e;

  --ink-900: #0f172a;
  --ink-800: #1e293b;
  --ink-700: #334155;
  --ink-600: #475569;
  --ink-500: #64748b;
  --ink-400: #94a3b8;
  --line: #e2e8f0;
  --line-soft: #eef2f7;

  --bg: #f7fafc;
  --bg-alt: #eef4f8;
  --surface: #ffffff;
  --surface-2: #f1f5f9;

  --brand: var(--teal-700);
  --brand-dark: var(--teal-800);
  --brand-soft: var(--teal-50);
  --accent: var(--orange-500);

  /* Code */
  --code-bg: #f6f8fb;
  --code-border: #e4ebf3;
  --inline-code-bg: #eef2f7;
  --inline-code-fg: #0e7490;

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

  /* Layout */
  --container: 1240px;
  --container-wide: 1440px;
  --measure: 78ch;            /* readable but wide on desktop */
  --header-h: 68px;
  --radius: 14px;
  --radius-sm: 9px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06), 0 1px 3px rgba(15, 23, 42, .05);
  --shadow-md: 0 6px 18px rgba(15, 23, 42, .08), 0 2px 6px rgba(15, 23, 42, .05);
  --shadow-lg: 0 18px 40px rgba(15, 23, 42, .12);
  --ring: 0 0 0 3px rgba(8, 145, 178, .35);
  --transition: 180ms cubic-bezier(.4, 0, .2, 1);
}

/* ----------------------------------------------------------------- reset */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink-800);
  background: var(--bg);
  line-height: 1.65;
  font-size: 1.0625rem;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; }
img { height: auto; }

a { color: var(--brand); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--brand-dark); }

.site-main { flex: 1 0 auto; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1rem, 3vw, 2.25rem);
}
@media (min-width: 1600px) {
  .container { max-width: var(--container-wide); }
}

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 1000;
  background: var(--brand); color: #fff; padding: .6rem 1rem; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 2px solid var(--teal-600); outline-offset: 2px; border-radius: 4px; }

/* ----------------------------------------------------------------- header */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; min-height: var(--header-h);
}
.brand { display: inline-flex; align-items: center; gap: .7rem; color: var(--ink-900); }
.brand:hover { color: var(--ink-900); }
.brand-logo { transition: transform var(--transition); }
.brand:hover .brand-logo { transform: rotate(-6deg) scale(1.06); }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-name { font-weight: 800; font-size: 1.12rem; letter-spacing: -.01em; }
.brand-accent { color: var(--brand); }
.brand-tag { font-size: .72rem; color: var(--ink-500); font-weight: 500; }

.nav-list { display: flex; align-items: center; gap: .35rem; list-style: none; margin: 0; padding: 0; }
.nav-link {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .55rem .85rem; border-radius: 10px; font-weight: 600; color: var(--ink-700);
  transition: background var(--transition), color var(--transition), transform var(--transition);
}
.nav-link:hover { background: var(--brand-soft); color: var(--brand-dark); transform: translateY(-1px); }
.nav-link.is-active { color: var(--brand-dark); background: var(--teal-100); }
.nav-icon { width: 19px; height: 19px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.has-menu { position: relative; }
.nav-submenu {
  position: absolute; top: calc(100% + 8px); left: 0; min-width: 320px;
  background: var(--surface); border: 1px solid var(--line); border-radius: 14px;
  box-shadow: var(--shadow-lg); padding: .5rem; list-style: none; margin: 0;
  opacity: 0; visibility: hidden; transform: translateY(6px);
  transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
}
.has-menu:hover .nav-submenu, .has-menu:focus-within .nav-submenu {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.nav-submenu a { display: block; padding: .6rem .75rem; border-radius: 9px; color: var(--ink-700); font-weight: 500; font-size: .95rem; }
.nav-submenu a:hover { background: var(--brand-soft); color: var(--brand-dark); }
.nav-submenu a.is-active { color: var(--brand-dark); font-weight: 600; }

.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: .5rem; border-radius: 10px; }
.nav-toggle-bar { display: block; width: 24px; height: 2.5px; background: var(--ink-700); border-radius: 2px; transition: var(--transition); }
.nav-toggle-bar + .nav-toggle-bar { margin-top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

@media (max-width: 860px) {
  .nav-toggle { display: block; }
  .primary-nav {
    position: fixed; inset: var(--header-h) 0 auto 0;
    background: var(--surface); border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    max-height: 0; overflow: hidden; transition: max-height var(--transition);
  }
  .primary-nav.open { max-height: 80vh; overflow: auto; }
  .nav-list { flex-direction: column; align-items: stretch; gap: .15rem; padding: .75rem; }
  .nav-link { width: 100%; }
  .nav-submenu {
    position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none;
    border: 0; border-left: 2px solid var(--line); border-radius: 0; margin: .25rem 0 .5rem 1.5rem; min-width: 0;
  }
}

/* ----------------------------------------------------------------- hero */
.hero {
  background:
    radial-gradient(1200px 480px at 12% -10%, rgba(8, 145, 178, .14), transparent 60%),
    radial-gradient(900px 420px at 95% 0%, rgba(99, 102, 241, .12), transparent 55%),
    linear-gradient(180deg, #ffffff, var(--bg));
  border-bottom: 1px solid var(--line);
  padding: clamp(2.5rem, 6vw, 5rem) 0 clamp(2.5rem, 5vw, 4rem);
}
.hero-inner { text-align: center; }
.hero-logo-row { display: flex; justify-content: center; margin-bottom: 1.25rem; }
.hero-logo { filter: drop-shadow(0 10px 24px rgba(14, 116, 144, .28)); animation: floaty 6s ease-in-out infinite; }
@keyframes floaty { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@media (prefers-reduced-motion: reduce) { .hero-logo { animation: none; } html { scroll-behavior: auto; } }

.hero-title {
  font-size: clamp(1.9rem, 4.4vw, 3.25rem); line-height: 1.08; letter-spacing: -.02em;
  font-weight: 800; color: var(--ink-900); margin: 0 0 .25rem; max-width: none;
}
.hero-title-accent {
  background: linear-gradient(120deg, var(--teal-600), var(--indigo-500));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-lede {
  max-width: none; margin: 1.4rem 0 0; color: var(--ink-600); font-size: 1.075rem;
  text-align: left;
}
.hero-lede p { margin: 0 0 1rem; }

.hero-cta { display: flex; flex-wrap: wrap; gap: .9rem; justify-content: center; margin-top: 2rem; }

/* ----------------------------------------------------------------- buttons */
.btn {
  display: inline-flex; align-items: center; gap: .65rem;
  padding: .8rem 1.25rem; border-radius: 12px; font-weight: 700; font-size: .98rem;
  border: 1px solid transparent; cursor: pointer; transition: var(--transition);
  box-shadow: var(--shadow-sm);
}
.btn-primary { background: linear-gradient(135deg, var(--teal-600), var(--teal-800)); color: #fff; }
.btn-primary:hover { color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-ghost { background: var(--surface); color: var(--ink-800); border-color: var(--line); }
.btn-ghost:hover { color: var(--brand-dark); border-color: var(--teal-600); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-icon { display: inline-flex; width: 30px; height: 30px; border-radius: 8px; align-items: center; justify-content: center; flex: none; }
.btn-icon svg { width: 18px; height: 18px; fill: none; stroke: #fff; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.btn-icon-teal { background: rgba(255,255,255,.18); }
.btn-icon-violet { background: rgba(255,255,255,.18); }
.btn-icon-amber { background: var(--amber-500); }
.btn-ghost .btn-icon svg { stroke: #fff; }

/* ----------------------------------------------------------------- sections */
.section { padding: clamp(2.5rem, 5vw, 4.5rem) 0; }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--line); }
.section-head { text-align: center; max-width: 60ch; margin: 0 auto 2.2rem; }
.section-title { font-size: clamp(1.5rem, 3vw, 2.1rem); font-weight: 800; letter-spacing: -.02em; color: var(--ink-900); margin: 0 0 .5rem; }
.section-sub { color: var(--ink-500); margin: 0; font-size: 1.05rem; }

/* ----------------------------------------------------------------- cards */
.card-grid {
  display: grid; gap: 1.25rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 320px), 1fr));
}
.card-grid-lg { grid-template-columns: repeat(auto-fit, minmax(min(100%, 380px), 1fr)); }
.card {
  display: flex; gap: 1rem; align-items: flex-start;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.25rem; box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  color: var(--ink-800);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--teal-600); color: var(--ink-800); }
.card-feature { padding: 1.5rem; }
.card-icon {
  flex: none; width: 48px; height: 48px; border-radius: 12px;
  display: inline-flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--teal-500), var(--teal-700)); color: #fff;
}
.card-icon svg { width: 26px; height: 26px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.card-icon-1 { background: linear-gradient(135deg, var(--teal-500), var(--teal-700)); }
.card-icon-2 { background: linear-gradient(135deg, var(--indigo-500), var(--violet-500)); }
.card-icon-3 { background: linear-gradient(135deg, var(--amber-500), var(--orange-500)); }
.card-icon-soft { background: linear-gradient(135deg, #e0f2fe, #cffafe); color: var(--teal-700); }
.card-text { display: flex; flex-direction: column; gap: .35rem; }
.card-heading { font-weight: 700; font-size: 1.08rem; color: var(--ink-900); line-height: 1.3; }
.card-summary { font-size: .92rem; color: var(--ink-500); line-height: 1.55; }
.card-link { margin-top: .25rem; font-weight: 600; color: var(--brand); font-size: .9rem; }
.card:hover .card-link { color: var(--brand-dark); }

/* ----------------------------------------------------------------- doc page */
.doc { padding: clamp(1.5rem, 3vw, 2.75rem) 0 3.5rem; }
/* Content pages share the same container width as the rest of the site. */
.doc-body {
  max-width: var(--measure);
  font-size: 1.075rem;
}
@media (min-width: 1100px) {
  .doc-body { max-width: 104ch; }
}
@media (min-width: 1400px) {
  /* Use the full width of the container on large / widescreen displays. */
  .doc-body { max-width: none; }
}

/* breadcrumbs */
.breadcrumbs { margin-bottom: 1.5rem; font-size: .88rem; }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; align-items: center; gap: .35rem .1rem; margin: 0; padding: 0; }
.breadcrumbs li { display: inline-flex; align-items: center; gap: .4rem; }
.breadcrumbs a { color: var(--ink-500); font-weight: 500; }
.breadcrumbs a:hover { color: var(--brand); }
.breadcrumbs .crumb-sep { color: var(--ink-400); }
.breadcrumbs [aria-current="page"] { color: var(--ink-800); font-weight: 600; }

/* doc typography */
.doc-body h1 {
  font-size: clamp(1.8rem, 3.6vw, 2.6rem); line-height: 1.15; letter-spacing: -.02em;
  font-weight: 800; margin: 0 0 1.1rem;
  background: linear-gradient(120deg, var(--teal-700), var(--indigo-600));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.doc-body h2 {
  font-size: clamp(1.4rem, 2.6vw, 1.85rem); font-weight: 750; color: var(--ink-900);
  letter-spacing: -.01em; margin: 2.4rem 0 .9rem; padding-top: .4rem;
  position: relative;
}
.doc-body h2::before {
  content: ""; position: absolute; left: 0; top: .55rem; bottom: .35rem; width: 4px; border-radius: 3px;
  background: linear-gradient(180deg, var(--teal-500), var(--indigo-500)); transform: translateX(-1rem);
  opacity: .85;
}
.doc-body h3 { font-size: 1.3rem; font-weight: 700; color: var(--teal-800); margin: 1.9rem 0 .7rem; }
.doc-body h4 { font-size: 1.1rem; font-weight: 700; color: var(--ink-800); margin: 1.5rem 0 .6rem; }
.doc-body h1, .doc-body h2, .doc-body h3, .doc-body h4 { scroll-margin-top: calc(var(--header-h) + 18px); }

.doc-body p { margin: 0 0 1.15rem; color: var(--ink-700); }
.doc-body strong { color: var(--ink-900); font-weight: 700; }
.doc-body ul, .doc-body ol { margin: 0 0 1.2rem; padding-left: 1.4rem; }
.doc-body li { margin: .4rem 0; color: var(--ink-700); }
.doc-body li::marker { color: var(--teal-600); }
.doc-body blockquote {
  margin: 1.4rem 0; padding: .9rem 1.2rem; border-left: 4px solid var(--teal-500);
  background: var(--brand-soft); border-radius: 0 10px 10px 0; color: var(--ink-700);
}

/* doc links */
.doc-body a:not(.header-anchor) {
  color: var(--brand-dark); font-weight: 550;
  background: linear-gradient(transparent 88%, rgba(8,145,178,.22) 0);
  transition: background var(--transition), color var(--transition);
}
.doc-body a:not(.header-anchor):hover {
  color: var(--teal-600);
  background: linear-gradient(transparent 0, rgba(8,145,178,.16) 0);
  border-radius: 3px;
}

/* header anchors */
.header-anchor {
  margin-left: .4rem; color: var(--ink-400); opacity: 0; text-decoration: none; font-weight: 600;
  transition: opacity var(--transition), color var(--transition);
}
.doc-body h2:hover .header-anchor,
.doc-body h3:hover .header-anchor,
.doc-body h4:hover .header-anchor { opacity: 1; }
.header-anchor:hover { color: var(--brand); }

/* ------------------------------------------------------ inline + code blocks */
.doc-body :not(pre) > code {
  font-family: var(--font-mono); font-size: .9em;
  background: var(--inline-code-bg); color: var(--inline-code-fg);
  padding: .12em .42em; border-radius: 6px; border: 0;
  word-break: break-word;
}
.code-block {
  position: relative; margin: 1.5rem 0;
  border: 1px solid var(--code-border); border-radius: var(--radius);
  background: var(--code-bg); box-shadow: var(--shadow-sm); overflow: hidden;
}
.code-block pre[class*="language-"] {
  margin: 0; padding: 1.1rem 1.2rem; overflow-x: auto; background: transparent;
  font-size: .9rem; line-height: 1.6; tab-size: 4;
}
.code-block code[class*="language-"] { font-family: var(--font-mono); background: transparent; }
.code-toolbar-bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: .45rem .65rem .45rem 1rem; background: #eef3f8; border-bottom: 1px solid var(--code-border);
}
.code-lang { font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-500); }
.copy-btn {
  display: inline-flex; align-items: center; gap: .4rem;
  font: inherit; font-size: .78rem; font-weight: 600; color: var(--ink-600);
  background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
  padding: .32rem .6rem; cursor: pointer; transition: var(--transition);
}
.copy-btn:hover { color: var(--brand-dark); border-color: var(--teal-600); background: var(--brand-soft); }
.copy-btn svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.copy-btn.copied { color: var(--emerald-500); border-color: var(--emerald-500); background: #ecfdf5; }

/* ---- Prism light theme (self-styled, matches palette) ---- */
.code-block code[class*="language-"],
.code-block pre[class*="language-"] {
  color: #2b3a4a; text-shadow: none;
  white-space: pre; word-spacing: normal; word-break: normal; tab-size: 4; hyphens: none;
}
.token.comment, .token.prolog, .token.doctype, .token.cdata { color: #7c8aa0; font-style: italic; }
.token.punctuation { color: #5b6b7d; }
.token.namespace { opacity: .7; }
.token.property, .token.tag, .token.constant, .token.symbol, .token.deleted { color: #c0392b; }
.token.boolean, .token.number { color: #b8581d; }
.token.selector, .token.attr-name, .token.string, .token.char, .token.builtin, .token.inserted { color: #0a7c66; }
.token.operator, .token.entity, .token.url { color: #4f5d6e; }
.token.atrule, .token.attr-value, .token.keyword { color: #6d28d9; font-weight: 600; }
.token.function, .token.class-name { color: #0e7490; font-weight: 600; }
.token.regex, .token.important, .token.variable { color: #d97706; }
.token.important, .token.bold { font-weight: 700; }
.token.italic { font-style: italic; }
.token.decorator, .token.annotation { color: #7c3aed; }

/* ----------------------------------------------------------------- tables */
.table-scroll { overflow-x: auto; margin: 1.6rem 0; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow-sm); -webkit-overflow-scrolling: touch; }
.table-scroll table { border-collapse: collapse; width: 100%; min-width: 560px; font-size: .95rem; }
.table-scroll thead th {
  background: linear-gradient(135deg, var(--teal-700), var(--teal-800)); color: #fff;
  text-align: left; font-weight: 650; padding: .8rem 1rem; white-space: nowrap;
}
.table-scroll tbody td { padding: .75rem 1rem; border-top: 1px solid var(--line); color: var(--ink-700); vertical-align: top; }
.table-scroll tbody tr:nth-child(even) { background: var(--surface-2); }
.table-scroll tbody tr:hover { background: var(--brand-soft); }
.table-scroll td code { white-space: nowrap; }

/* --------------------------------------------------------- task checkboxes */
.contains-task-list { list-style: none; padding-left: .25rem; }
.task-list-item { position: relative; padding-left: 0; display: flex; align-items: flex-start; gap: .6rem; }
.task-list-item::marker { content: ""; }
.task-checkbox {
  appearance: none; -webkit-appearance: none;
  flex: none; width: 1.2em; height: 1.2em; margin-top: .25em;
  border: 2px solid var(--teal-600); border-radius: 6px; background: var(--surface);
  cursor: pointer; position: relative; transition: var(--transition);
}
.task-checkbox:hover { box-shadow: var(--ring); }
.task-checkbox:checked { background: var(--teal-600); border-color: var(--teal-600); }
.task-checkbox:checked::after {
  content: ""; position: absolute; left: 4px; top: 1px; width: 5px; height: 9px;
  border: solid #fff; border-width: 0 2.5px 2.5px 0; transform: rotate(45deg);
}
.task-list-item.checked { color: var(--ink-400); text-decoration: line-through; text-decoration-color: var(--ink-400); }

/* ----------------------------------------------------------------- accordions */
.faq-accordion { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin: 1.5rem 0; box-shadow: var(--shadow-sm); background: var(--surface); }
.faq-item + .faq-item { border-top: 1px solid var(--line); }
.faq-q {
  width: 100%; text-align: left; background: var(--surface); border: 0; cursor: pointer;
  font: inherit; font-weight: 650; color: var(--ink-900); font-size: 1.02rem;
  padding: 1rem 1.2rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  transition: background var(--transition);
}
.faq-q:hover { background: var(--brand-soft); }
.faq-icon { flex: none; width: 20px; height: 20px; transition: transform var(--transition); color: var(--teal-600); }
.faq-icon svg { width: 100%; height: 100%; fill: none; stroke: currentColor; stroke-width: 2.5; stroke-linecap: round; }
.faq-q[aria-expanded="true"] .faq-icon { transform: rotate(45deg); }
.faq-a { padding: 0 1.2rem; max-height: 0; overflow: hidden; transition: max-height var(--transition), padding var(--transition); }
.faq-a.open { padding: 0 1.2rem 1.1rem; }
.faq-a > :first-child { margin-top: 0; }

/* ----------------------------------------------------------------- mermaid */
.mermaid-wrap { position: relative; margin: 1.6rem 0; padding: 1.25rem; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow-sm); overflow-x: auto; text-align: center; }
.mermaid { font-family: var(--font-sans) !important; }
.mermaid:not([data-processed]) { color: transparent; min-height: 2rem; }
.mermaid-wrap svg { max-width: 100%; height: auto; }

/* Click-to-enlarge affordance on rendered diagrams */
.mermaid-wrap.is-enlargeable { cursor: zoom-in; transition: box-shadow var(--transition), border-color var(--transition); }
.mermaid-wrap.is-enlargeable:hover { border-color: var(--teal-600); box-shadow: var(--shadow-md); }
.diagram-expand {
  position: absolute; top: .6rem; right: .6rem; z-index: 2;
  display: inline-flex; align-items: center; gap: .35rem;
  font: inherit; font-size: .76rem; font-weight: 600; color: var(--ink-600);
  background: rgba(255, 255, 255, .9); border: 1px solid var(--line); border-radius: 8px;
  padding: .3rem .55rem; cursor: zoom-in; opacity: 0;
  transition: opacity var(--transition), color var(--transition), border-color var(--transition);
}
.mermaid-wrap.is-enlargeable:hover .diagram-expand,
.mermaid-wrap.is-enlargeable:focus-within .diagram-expand { opacity: 1; }
.diagram-expand:hover { color: var(--brand-dark); border-color: var(--teal-600); }
.diagram-expand svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* Fullscreen diagram lightbox */
.diagram-lightbox {
  position: fixed; inset: 0; z-index: 1000;
  display: flex; flex-direction: column;
  background: rgba(15, 23, 42, .82); backdrop-filter: blur(6px);
  opacity: 0; visibility: hidden; transition: opacity var(--transition), visibility var(--transition);
  padding: clamp(.75rem, 2vw, 1.5rem);
}
.diagram-lightbox.open { opacity: 1; visibility: visible; }
.diagram-lightbox-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  color: #fff; padding: .25rem .5rem .75rem;
}
.diagram-lightbox-title { font-weight: 650; font-size: 1rem; color: #fff; margin: 0; }
.diagram-lightbox-actions { display: flex; align-items: center; gap: .5rem; }
.diagram-lightbox-btn {
  display: inline-flex; align-items: center; gap: .4rem;
  font: inherit; font-size: .82rem; font-weight: 600; color: #e2e8f0;
  background: rgba(255, 255, 255, .1); border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 9px; padding: .45rem .7rem; cursor: pointer; transition: var(--transition);
}
.diagram-lightbox-btn:hover { background: rgba(255, 255, 255, .2); color: #fff; }
.diagram-lightbox-btn svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.diagram-lightbox-stage {
  flex: 1 1 auto; min-height: 0;
  display: flex; align-items: center; justify-content: center;
  background: #fff; border-radius: var(--radius); overflow: auto; padding: 1.5rem;
}
.diagram-lightbox-stage svg {
  max-width: none; width: auto; height: auto;
  transform: scale(var(--diagram-zoom, 1)); transform-origin: center center;
  transition: transform 120ms ease-out;
}

/* ----------------------------------------------------------------- related */
.related, .related-links { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--line); }
.related-title { font-size: 1.25rem; font-weight: 750; color: var(--ink-900); margin: 0 0 1.2rem; }
.pill-list { list-style: none; display: flex; flex-wrap: wrap; gap: .6rem; padding: 0; margin: 0; }
.pill {
  display: inline-flex; padding: .5rem .9rem; border-radius: 999px; font-size: .9rem; font-weight: 600;
  background: var(--surface); border: 1px solid var(--line); color: var(--ink-700); box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.pill:hover { color: var(--brand-dark); border-color: var(--teal-600); background: var(--brand-soft); transform: translateY(-2px); }

/* ----------------------------------------------------------------- footer */
.site-footer { flex-shrink: 0; background: linear-gradient(180deg, #0f2730, #0b1f27); color: #cbd5e1; margin-top: 3rem; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 2.5rem; justify-content: space-between; padding-block: 2.75rem; }
.footer-brand { display: flex; gap: 1rem; align-items: flex-start; max-width: 420px; }
.footer-logo { background: rgba(255,255,255,.06); border-radius: 10px; padding: 4px; }
.footer-name { font-weight: 800; color: #fff; margin: 0 0 .35rem; font-size: 1.05rem; }
.footer-desc { margin: 0; font-size: .92rem; color: #94a3b8; line-height: 1.55; }
.footer-nav .footer-heading { font-size: .78rem; text-transform: uppercase; letter-spacing: .1em; color: #64748b; margin: 0 0 .9rem; font-weight: 700; }
.footer-nav ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .55rem; }
.footer-nav a { color: #cbd5e1; font-weight: 500; }
.footer-nav a:hover { color: var(--teal-500); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding-block: 1.1rem; font-size: .85rem; color: #64748b; }
.footer-bottom p { margin: 0; }

/* ----------------------------------------------------------------- utilities */
.section-alt .card { background: var(--surface); }
@media (max-width: 600px) {
  body { font-size: 1rem; }
  .doc-body { font-size: 1rem; }
}