/* ============================================================================
   BabyChain Docs — Open Design polished CSS
   Brand: Gold (#E8C97A) · Dark mode (#0B0B0F) · Inter + Outfit
   ============================================================================ */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@500;600;700;800&display=swap');

/* ==========================================================================
   Design tokens
   ========================================================================== */
:root {
  /* Brand — Gold */
  --color-primary: #E8C97A;
  --color-primary-dark: #D4A847;
  --color-primary-darker: #B98E33;
  --color-primary-deeper: #8E7530;
  --color-primary-soft: #FEF3C7;
  --color-primary-fade: #FFFBEB;
  --color-primary-glow: rgba(232, 201, 122, 0.12);

  /* Text */
  --color-text: #0F172A;
  --color-text-muted: #475569;
  --color-text-subtle: #94A3B8;
  --color-text-inverse: #FFFFFF;

  /* Surfaces */
  --color-bg: #FFFFFF;
  --color-bg-subtle: #F8FAFC;
  --color-bg-muted: #F1F5F9;
  --color-bg-inverse: #0F172A;

  /* Borders */
  --color-border: #E2E8F0;
  --color-border-strong: #CBD5E1;

  /* Semantic hints */
  --color-info-bg: #EFF6FF;
  --color-info-border: #3B82F6;
  --color-info-text: #1E40AF;

  --color-success-bg: #F0FDF4;
  --color-success-border: #D4A847;
  --color-success-text: #15803D;

  --color-warning-bg: #FFFBEB;
  --color-warning-border: #E8C97A;
  --color-warning-text: #8E7530;

  --color-danger-bg: #FEF2F2;
  --color-danger-border: #EF4444;
  --color-danger-text: #991B1B;

  --color-tip-bg: #FAF5FF;
  --color-tip-border: #A855F7;
  --color-tip-text: #6B21A8;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-display: "Outfit", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", "Fira Code", Consolas, "Courier New", monospace;

  /* Type scale */
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 1.875rem;
  --fs-3xl: 2.25rem;
  --fs-4xl: 3rem;
  --fs-5xl: 3.75rem;

  /* Line height */
  --lh-tight: 1.2;
  --lh-snug: 1.35;
  --lh-normal: 1.6;
  --lh-relaxed: 1.75;

  /* Spacing */
  --sp-1: .25rem;
  --sp-2: .5rem;
  --sp-3: .75rem;
  --sp-4: 1rem;
  --sp-5: 1.25rem;
  --sp-6: 1.5rem;
  --sp-8: 2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;
  --sp-20: 5rem;
  --sp-24: 6rem;

  /* Layout */
  --sidebar-width: 280px;
  --topbar-height: 64px;
  --content-max: 760px;
  --right-rail: 240px;

  /* Border radius */
  --radius-sm: 6px;
  --radius: 10px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-pill: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(15, 23, 42, .04);
  --shadow: 0 1px 3px 0 rgba(15, 23, 42, .06), 0 1px 2px -1px rgba(15, 23, 42, .04);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, .08), 0 2px 4px -2px rgba(15, 23, 42, .04);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, .08), 0 4px 6px -4px rgba(15, 23, 42, .04);
  --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, .1), 0 8px 10px -6px rgba(15, 23, 42, .04);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(.4, 0, .2, 1);
  --transition: 200ms cubic-bezier(.4, 0, .2, 1);
  --transition-slow: 350ms cubic-bezier(.4, 0, .2, 1);
}

/* ==========================================================================
   Dark mode — data-theme="dark" is the single source of truth.
   The default (no data-theme or data-theme="light") is light.
   data-theme="dark" overrides regardless of system preference.
   System preference is only used as the initial default before user choice.
   ========================================================================== */
:root[data-theme="dark"] {
  --color-text: #F0EDE8;
  --color-text-muted: #A8A29E;
  --color-text-subtle: #78716C;
  --color-text-inverse: #0F172A;

  --color-bg: #0B0B0F;
  --color-bg-subtle: #131317;
  --color-bg-muted: #1C1C23;
  --color-bg-inverse: #E2E8F0;

  --color-border: #1E1E26;
  --color-border-strong: #2E2E38;

  --color-primary-soft: rgba(232, 201, 122, .12);
  --color-primary-fade: rgba(232, 201, 122, .08);
  --color-primary-glow: rgba(232, 201, 122, .2);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .2);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, .3), 0 1px 2px -1px rgba(0, 0, 0, .2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4), 0 2px 4px -2px rgba(0, 0, 0, .3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .5), 0 4px 6px -4px rgba(0, 0, 0, .4);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .6), 0 8px 10px -6px rgba(0, 0, 0, .4);

  --color-info-bg: #0C1524;
  --color-info-text: #93C5FD;
  --color-success-bg: #0A140A;
  --color-success-text: #86EFAC;
  --color-warning-bg: #141008;
  --color-warning-text: #FDE68A;
  --color-danger-bg: #1C0A0A;
  --color-danger-text: #FCA5A5;
  --color-tip-bg: #140A1C;
  --color-tip-text: #D8B4FE;

  /* Topbar surface — semantic */
  --topbar-bg: rgba(11, 11, 15, .88);

  /* Mermaid surfaces — keep diagrams legible on dark */
  --mermaid-bg: #131317;
  --mermaid-text: #F0EDE8;
  --mermaid-edge: #A8A29E;
  --mermaid-edge-label: #0B0B0F;
  --mermaid-node-fill: #1C1C23;
  --mermaid-node-stroke: #E8C97A;
}

/* Light is the default. No overrides needed — :root tokens are already light. */
:root[data-theme="light"] {
  --topbar-bg: rgba(255, 255, 255, .88);
  --mermaid-bg: #FFFFFF;
  --mermaid-text: #0F172A;
  --mermaid-edge: #475569;
  --mermaid-edge-label: #FFFFFF;
  --mermaid-node-fill: #F8FAFC;
  --mermaid-node-stroke: #D4A847;
}

/* If the user has never chosen, follow system preference on first paint only. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-text: #F0EDE8;
    --color-text-muted: #A8A29E;
    --color-text-subtle: #78716C;
    --color-text-inverse: #0F172A;
    --color-bg: #0B0B0F;
    --color-bg-subtle: #131317;
    --color-bg-muted: #1C1C23;
    --color-bg-inverse: #E2E8F0;
    --color-border: #1E1E26;
    --color-border-strong: #2E2E38;
    --color-primary-soft: rgba(232, 201, 122, .12);
    --color-primary-fade: rgba(232, 201, 122, .08);
    --color-primary-glow: rgba(232, 201, 122, .2);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .2);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, .3), 0 1px 2px -1px rgba(0, 0, 0, .2);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4), 0 2px 4px -2px rgba(0, 0, 0, .3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .5), 0 4px 6px -4px rgba(0, 0, 0, .4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .6), 0 8px 10px -6px rgba(0, 0, 0, .4);
    --color-info-bg: #0C1524;
    --color-info-text: #93C5FD;
    --color-success-bg: #0A140A;
    --color-success-text: #86EFAC;
    --color-warning-bg: #141008;
    --color-warning-text: #FDE68A;
    --color-danger-bg: #1C0A0A;
    --color-danger-text: #FCA5A5;
    --color-tip-bg: #140A1C;
    --color-tip-text: #D8B4FE;
    --topbar-bg: rgba(11, 11, 15, .88);
    --mermaid-bg: #131317;
    --mermaid-text: #F0EDE8;
    --mermaid-edge: #A8A29E;
    --mermaid-edge-label: #0B0B0F;
    --mermaid-node-fill: #1C1C23;
    --mermaid-node-stroke: #E8C97A;
  }
}

/* ==========================================================================
   Keyframes — restrained motion
   ========================================================================== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }

html {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar-height) + var(--sp-6));
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--color-text);
  background: var(--color-bg);
  font-feature-settings: "cv11", "ss01", "ss03";
  transition: background var(--transition), color var(--transition);
}

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

a {
  color: var(--color-primary-dark);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--color-primary-darker);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1.5px;
}

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: var(--sp-8) 0;
}

::selection {
  background: var(--color-primary-soft);
  color: var(--color-text);
}

.logo img { transition: opacity var(--transition); }
.logo:hover img { opacity: .8; }

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.025em;
  line-height: var(--lh-tight);
  margin: 0 0 var(--sp-4);
}

h1 { font-size: var(--fs-3xl); margin-top: 0; font-weight: 800; letter-spacing: -0.03em; }
h2 { font-size: var(--fs-2xl); margin-top: var(--sp-12); font-weight: 700; letter-spacing: -0.025em; }
h3 { font-size: var(--fs-xl); margin-top: var(--sp-8); font-weight: 700; }
h4 { font-size: var(--fs-lg); margin-top: var(--sp-6); font-weight: 600; }

p { margin: 0 0 var(--sp-4); }
strong { font-weight: 600; color: var(--color-text); }
small { font-size: var(--fs-sm); color: var(--color-text-muted); }

ul, ol { margin: 0 0 var(--sp-4); padding-left: 1.5em; }
li { margin: .25em 0; }
li > ul, li > ol { margin: .25em 0; }

code {
  font-family: var(--font-mono);
  font-size: .9em;
  background: var(--color-bg-muted);
  color: var(--color-text);
  padding: .15em .4em;
  border-radius: 4px;
  word-break: break-word;
}

blockquote {
  margin: 0 0 var(--sp-4);
  padding: var(--sp-3) var(--sp-5);
  border-left: 3px solid var(--color-primary);
  background: var(--color-primary-fade);
  color: var(--color-text-muted);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
}
blockquote p:last-child { margin-bottom: 0; }

.eyebrow {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--color-primary-dark);
  margin-bottom: var(--sp-2);
}

/* ==========================================================================
   Top bar
   ========================================================================== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--topbar-height);
  background: var(--topbar-bg);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  padding: 0 var(--sp-6);
  gap: var(--sp-4);
  transition: background var(--transition), color var(--transition);
}

.topbar .logo {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-weight: 700;
  font-size: var(--fs-md);
  color: var(--color-text);
  white-space: nowrap;
  text-decoration: none;
}
.topbar .logo:hover { color: var(--color-text); text-decoration: none; }
.topbar .logo img { height: 28px; width: 28px; flex-shrink: 0; }
.topbar .logo span { font-family: var(--font-display); font-weight: 700; }

.topbar .search {
  flex: 1;
  max-width: 480px;
  margin: 0 auto;
  position: relative;
}
.topbar .search input {
  width: 100%;
  height: 38px;
  padding: 0 var(--sp-4) 0 38px;
  font: inherit;
  font-size: var(--fs-sm);
  color: var(--color-text);
  background: var(--color-bg-muted);
  border: 1px solid transparent;
  border-radius: var(--radius);
  outline: none;
  transition: all var(--transition-fast);
}
.topbar .search input:focus {
  background: var(--color-bg);
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-soft);
}
.topbar .search input::placeholder { color: var(--color-text-subtle); }
.topbar .search svg {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--color-text-subtle);
  pointer-events: none;
}
.topbar .search kbd {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  padding: 2px 6px;
  font: 11px/1 var(--font-mono);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  color: var(--color-text-muted);
  pointer-events: none;
}

.topbar .nav-pills {
  display: flex;
  gap: var(--sp-2);
  align-items: center;
}
.topbar .nav-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-primary);
  border-radius: var(--radius);
  text-decoration: none;
  transition: all var(--transition-fast);
  white-space: nowrap;
}
.topbar .nav-pill:hover { background: var(--color-primary-dark); color: var(--color-text); text-decoration: none; transform: translateY(-1px); }
.topbar .nav-pill.secondary { background: var(--color-bg-muted); }
.topbar .nav-pill.secondary:hover { background: var(--color-border); }

.topbar .icon-btn {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-muted);
  border: 0;
  border-radius: var(--radius);
  color: var(--color-text);
  cursor: pointer;
  font: inherit;
  transition: background var(--transition-fast);
}
.topbar .icon-btn:hover { background: var(--color-border); }

.menu-toggle { display: none; }

/* ==========================================================================
   Layout
   ========================================================================== */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: calc(100vh - var(--topbar-height));
  animation: fadeIn .4s ease-out;
}

/* ==========================================================================
   Sidebar
   ========================================================================== */
.sidebar {
  position: sticky;
  top: var(--topbar-height);
  height: calc(100vh - var(--topbar-height));
  overflow-y: auto;
  padding: var(--sp-6) var(--sp-4) var(--sp-12) var(--sp-6);
  border-right: 1px solid var(--color-border);
  background: var(--color-bg);
  transition: background var(--transition);
}

.sidebar-group { margin-bottom: var(--sp-6); }

.sidebar-label {
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--color-text-muted);
  margin: 0 0 var(--sp-3);
  padding: 0 var(--sp-2);
}

.sidebar ul { list-style: none; padding: 0; margin: 0; }
.sidebar li { margin: 0; }

.sidebar li a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  text-decoration: none;
  line-height: 1.4;
  transition: all var(--transition-fast);
  border-left: 2px solid transparent;
}
.sidebar li a:hover {
  color: var(--color-text);
  background: var(--color-bg-muted);
  text-decoration: none;
}

.sidebar li.active > a {
  color: var(--color-primary-darker);
  background: var(--color-primary-fade);
  font-weight: 600;
  border-left-color: var(--color-primary);
}

.sidebar li .icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--color-text-subtle);
}
.sidebar li.active .icon { color: var(--color-primary-dark); }

/* ==========================================================================
   Main content
   ========================================================================== */
.main {
  padding: var(--sp-10) var(--sp-12) var(--sp-16);
  max-width: calc(var(--content-max) + var(--right-rail) + var(--sp-12));
  margin: 0 auto;
  width: 100%;
}

.article {
  max-width: var(--content-max);
}

.article-hero {
  margin: 0 0 var(--sp-6);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-bg-muted);
}
.article-hero img { width: 100%; height: auto; display: block; }

.article-header {
  margin-bottom: var(--sp-8);
}

.article-header h1 {
  font-size: var(--fs-3xl);
  margin: 0;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

.article-header h1 .title-icon {
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  margin: 0;
  padding: 6px;
  object-fit: contain;
  box-sizing: border-box;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: var(--color-bg-subtle);
  box-shadow: none;
  align-self: center;
}

/* Smaller on narrow screens — keeps the icon proportional to the H1. */
@media (max-width: 640px) {
  .article-header h1 .title-icon {
    width: 36px;
    height: 36px;
    flex: 0 0 36px;
    padding: 4px;
    border-radius: 8px;
  }
}

.article-meta {
  display: flex;
  gap: var(--sp-4);
  align-items: center;
  margin-top: var(--sp-3);
  font-size: var(--fs-sm);
  color: var(--color-text-subtle);
}

.copy-page-btn {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font: inherit;
  transition: all var(--transition-fast);
}
.copy-page-btn:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
  border-color: var(--color-primary);
}
.copy-page-btn.copied {
  color: var(--color-success-text);
  border-color: var(--color-success-border);
  background: var(--color-success-bg);
}

/* ==========================================================================
   Home page — Hero + Cards
   ========================================================================== */
.home { max-width: var(--content-max); }

.home-hero {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: var(--sp-10);
  background: #0A0A0F;
}
.home-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 5%, var(--color-primary) 30%, var(--color-primary) 70%, transparent 95%);
  z-index: 1;
}
.home-hero::after {
  content: "";
  position: absolute;
  top: -40%;
  right: -10%;
  width: 50%;
  height: 100%;
  background: radial-gradient(ellipse at center, rgba(232, 201, 122, .08) 0%, transparent 70%);
  pointer-events: none;
}
.home-hero img { width: 100%; height: auto; display: block; }

.home-hero-text {
  position: relative;
  z-index: 2;
  padding: var(--sp-12) var(--sp-10);
  color: #fff;
}
.home-hero-text h1 {
  font-family: var(--font-display);
  color: #fff;
  font-size: var(--fs-4xl);
  font-weight: 800;
  margin-bottom: var(--sp-3);
  letter-spacing: -.03em;
  line-height: 1.1;
}
.home-hero-text .subtitle {
  font-size: var(--fs-md);
  color: #A8A29E;
  max-width: 520px;
  line-height: var(--lh-relaxed);
}

.home-eyebrow {
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .15em;
  color: var(--color-primary);
  margin-bottom: var(--sp-3);
}

.home-hero-text .badges {
  display: flex;
  gap: var(--sp-2);
  margin-top: var(--sp-6);
  flex-wrap: wrap;
}
.home-hero-text .badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-size: var(--fs-xs);
  font-weight: 600;
  font-family: var(--font-mono);
  border-radius: var(--radius-pill);
  background: rgba(232, 201, 122, .12);
  color: #E8C97A;
  border: 1px solid rgba(232, 201, 122, .25);
  letter-spacing: .02em;
}

.home-section {
  margin: var(--sp-12) 0;
  animation: fadeInUp .5s ease-out both;
}
.home-section:nth-child(1) { animation-delay: .1s; }
.home-section:nth-child(2) { animation-delay: .2s; }
.home-section:nth-child(3) { animation-delay: .3s; }
.home-section:nth-child(4) { animation-delay: .4s; }
.home-section:nth-child(5) { animation-delay: .5s; }

.home-section h2 {
  font-size: var(--fs-xl);
  font-family: var(--font-display);
  margin-top: 0;
  margin-bottom: var(--sp-4);
  letter-spacing: -.02em;
}

.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--sp-3);
}

.home-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: var(--sp-5) var(--sp-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--color-text);
  transition: all var(--transition);
  position: relative;
  min-height: 80px;
}
.home-card:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-fade);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  text-decoration: none;
}
.home-card .card-title {
  font-weight: 600;
  font-size: var(--fs-base);
  margin-bottom: 4px;
  font-family: var(--font-display);
}
.home-card .card-desc {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  line-height: var(--lh-snug);
}
.home-card .card-arrow {
  color: var(--color-primary);
  margin-top: var(--sp-3);
  display: flex;
  align-self: flex-end;
  transition: transform var(--transition-fast);
}
.home-card:hover .card-arrow {
  transform: translateX(4px);
}
.home-card .card-icon {
  width: 24px;
  height: 24px;
  color: var(--color-primary-dark);
  margin-bottom: var(--sp-2);
}

/* ==========================================================================
   Code blocks
   ========================================================================== */
pre {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  background: var(--color-bg-inverse);
  color: #E2E8F0;
  padding: var(--sp-5) var(--sp-5);
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 0 0 var(--sp-4);
  position: relative;
  border: 1px solid transparent;
}
@media (prefers-color-scheme: dark) {
  pre:not([data-theme="light"]) {
    background: #0D0D12;
    border-color: var(--color-border);
    color: #E2E0D8;
  }
}
:root[data-theme="dark"] pre {
  background: #0D0D12;
  border-color: var(--color-border);
  color: #E2E0D8;
}
pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  font-size: inherit;
  border-radius: 0;
}

/* ==========================================================================
   Tables — with sticky headers
   ========================================================================== */
.table-wrap {
  overflow-x: auto;
  margin: 0 0 var(--sp-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-sm);
}
th, td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}
th {
  background: var(--color-bg-subtle);
  font-weight: 600;
  color: var(--color-text);
  position: sticky;
  top: 0;
  z-index: 1;
}
tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--color-bg-subtle); }

/* ==========================================================================
   Hints — GitBook-style
   ========================================================================== */
.hint {
  display: flex;
  gap: var(--sp-3);
  padding: var(--sp-4) var(--sp-5);
  border-radius: var(--radius);
  border: 1px solid;
  margin: 0 0 var(--sp-4);
  font-size: var(--fs-sm);
  line-height: 1.6;
}
.hint-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 2px;
}
.hint-body { flex: 1; }
.hint-body p:first-child { margin-top: 0; }
.hint-body p:last-child { margin-bottom: 0; }
.hint-body strong:first-child { display: block; margin-bottom: 4px; }

.hint.info { background: var(--color-info-bg); border-color: var(--color-info-border); color: var(--color-info-text); }
.hint.info .hint-icon { color: var(--color-info-border); }
.hint.success { background: var(--color-success-bg); border-color: var(--color-success-border); color: var(--color-success-text); }
.hint.success .hint-icon { color: var(--color-success-border); }
.hint.warning { background: var(--color-warning-bg); border-color: var(--color-warning-border); color: var(--color-warning-text); }
.hint.warning .hint-icon { color: var(--color-warning-border); }
.hint.danger { background: var(--color-danger-bg); border-color: var(--color-danger-border); color: var(--color-danger-text); }
.hint.danger .hint-icon { color: var(--color-danger-border); }
.hint.tip { background: var(--color-tip-bg); border-color: var(--color-tip-border); color: var(--color-tip-text); }
.hint.tip .hint-icon { color: var(--color-tip-border); }

/* ==========================================================================
   Tabs
   ========================================================================== */
.tabs {
  margin: 0 0 var(--sp-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}
.tab-buttons {
  display: flex;
  background: var(--color-bg-subtle);
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
}
.tab-btn {
  padding: 10px 18px;
  border: 0;
  background: transparent;
  font: inherit;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: all var(--transition-fast);
  font-family: var(--font-display);
}
.tab-btn:hover { color: var(--color-text); }
.tab-btn.active {
  color: var(--color-primary-darker);
  border-bottom-color: var(--color-primary);
  background: var(--color-bg);
}
.tab-panels { padding: var(--sp-4) var(--sp-5); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.tab-panel > *:last-child { margin-bottom: 0; }
.tab-panel > *:first-child { margin-top: 0; }

/* ==========================================================================
   Mermaid
   ========================================================================== */
.mermaid {
  background: var(--color-bg);
  text-align: center;
  margin: 0 0 var(--sp-4);
  padding: var(--sp-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow-x: auto;
}
pre.mermaid {
  background: var(--color-bg);
  color: var(--color-text);
  padding: var(--sp-5);
}

/* ==========================================================================
   Inline images
   ========================================================================== */
.article img {
  max-width: 100%;
  border-radius: var(--radius);
  margin: var(--sp-3) 0;
}
/* Inline article SVG illustrations (NOT title icons — those are scoped below).
   Exclude `.title-icon` so title icons don't pick up the heavy padding + background. */
.article img[src$=".svg"]:not(.title-icon) {
  background: var(--color-bg-subtle);
  padding: var(--sp-4);
  border: 1px solid var(--color-border);
}

/* ==========================================================================
   Prev / Next navigation
   ========================================================================== */
.prev-next {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-3);
  margin: var(--sp-12) 0 var(--sp-6);
  padding-top: var(--sp-8);
  border-top: 1px solid var(--color-border);
}
.prev-next .nav {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--sp-4) var(--sp-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--color-text);
  transition: all var(--transition);
  position: relative;
  min-height: 80px;
}
.prev-next .nav:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-fade);
  text-decoration: none;
  transform: translateY(-1px);
}
.prev-next .nav .label {
  font-size: var(--fs-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}
.prev-next .nav .title {
  font-size: var(--fs-base);
  font-weight: 600;
  font-family: var(--font-display);
}
.prev-next .nav.next { text-align: right; }
.prev-next .nav .arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-subtle);
  transition: color var(--transition-fast);
}
.prev-next .nav.prev .arrow { left: 16px; }
.prev-next .nav.next .arrow { right: 16px; }
.prev-next .nav:hover .arrow { color: var(--color-primary-dark); }
.prev-next .nav .label, .prev-next .nav .title { padding: 0 24px; }
.prev-next .spacer { display: block; }

/* ==========================================================================
   Search results
   ========================================================================== */
.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  margin-top: 4px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-height: 60vh;
  overflow-y: auto;
  display: none;
  z-index: 100;
}
.search-results.active { display: block; }

.search-result {
  display: block;
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
  text-decoration: none;
  color: var(--color-text);
  transition: background var(--transition-fast);
}
.search-result:last-child { border-bottom: 0; }
.search-result:hover, .search-result.focused { background: var(--color-bg-muted); text-decoration: none; }
.search-result .result-title {
  font-weight: 600;
  font-size: var(--fs-sm);
  margin-bottom: 2px;
  font-family: var(--font-display);
}
.search-result .result-path {
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
  font-family: var(--font-mono);
}
.search-result .result-snippet {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: 4px;
  line-height: 1.4;
}
.search-result mark {
  background: var(--color-primary-soft);
  color: var(--color-text);
  padding: 0 2px;
  border-radius: 2px;
}
.search-empty {
  padding: 16px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--sp-6);
  text-align: center;
  font-size: var(--fs-sm);
  color: var(--color-text-subtle);
  background: var(--color-bg-subtle);
  transition: background var(--transition), color var(--transition);
}
.site-footer a { color: var(--color-text-muted); }

/* ==========================================================================
   Misc
   ========================================================================== */
.last-updated {
  margin-top: var(--sp-8);
  font-size: var(--fs-sm);
  color: var(--color-text-subtle);
}

.kbd-key {
  display: inline-block;
  padding: 1px 6px;
  font: 11px/1.4 var(--font-mono);
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive — Tablet (<= 1024px)
   ========================================================================== */
@media (max-width: 1024px) {
  .layout { grid-template-columns: 1fr; }

  .sidebar {
    position: fixed;
    left: -100%;
    top: var(--topbar-height);
    width: var(--sidebar-width);
    height: calc(100vh - var(--topbar-height));
    z-index: 40;
    background: var(--color-bg);
    transition: left var(--transition);
    box-shadow: var(--shadow-lg);
  }
  .sidebar.open { left: 0; }

  .main { padding: var(--sp-6); }
  .article-header h1 { font-size: var(--fs-2xl); }
  .home-hero-text h1 { font-size: var(--fs-3xl); }
  .topbar .nav-pills .nav-pill.secondary { display: none; }
  .menu-toggle { display: inline-flex; }
}

/* ==========================================================================
   Responsive — Mobile (<= 640px)
   ========================================================================== */
@media (max-width: 640px) {
  .topbar { padding: 0 var(--sp-3); }
  .topbar .search { display: none; }
  .topbar .nav-pills { gap: 4px; }
  .topbar .nav-pill { padding: 4px 10px; font-size: var(--fs-xs); }

  .main { padding: var(--sp-4); }
  .article-header h1 { font-size: var(--fs-xl); }
  .article-meta { flex-wrap: wrap; }
  .copy-page-btn { margin-left: 0; }

  .home-hero-text { padding: var(--sp-8) var(--sp-6); }
  .home-hero-text h1 { font-size: var(--fs-2xl); }
  .home-hero-text .subtitle { font-size: var(--fs-sm); }
  .home-grid { grid-template-columns: 1fr; }
  .prev-next { grid-template-columns: 1fr; gap: var(--sp-2); }
}