/* ==========================================================================
   AUDIT COMMONS — Editorial Design System
   Visual direction: White paper, graphite typography, fine gray rules,
   and a single blue interaction color. Flat surfaces and generous whitespace.
   Zero external fonts or remote asset dependencies.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design Tokens & CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
  /* White, graphite and blue */
  --color-bg: #ffffff;
  --color-bg-subtle: #f3f4f5;
  --color-surface: #ffffff;
  --color-surface-tint: #f5f5f4;
  --color-surface-hover: #fafafa;

  --color-primary: #232323;
  --color-primary-dark: #161616;
  --color-primary-light: #414141;
  --color-primary-subtle: #f0f1f2;
  --color-primary-subtle-hover: #e6e8eb;

  --color-accent: #254fc4;
  --color-accent-dark: #183b9c;
  --color-accent-subtle: #edf1fc;

  --color-text: #222222;
  --color-text-muted: #585b62;
  --color-text-subtle: #65676c;

  --color-border: #dcdde0;
  --color-border-subtle: #ededee;
  --color-border-strong: #232323;
  --color-rule-accent: #254fc4;

  /* Typography Stacks (Strictly Local / System) */
  --font-serif: "Iowan Old Style", "Apple Garamond", "Baskerville", "Georgia Pro", "Palatino Linotype", "Palatino", Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Consolas", "Liberation Mono", Menlo, Courier, monospace;

  /* Layout & Geometry */
  --max-width: 1160px;
  --content-width: 70ch;
  --radius-sm: 0;
  --radius-md: 0;

  /* Elevations */
  --shadow-subtle: none;
  --shadow-lift: none;
}

/* --------------------------------------------------------------------------
   2. Reset & Document Foundation
   -------------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

[id] { scroll-margin-top: 9rem; }

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main#main {
  flex: 1 0 auto;
}

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

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--color-border);
  transition: color 0.15s ease, text-decoration-color 0.15s ease;
}

a:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

/* --------------------------------------------------------------------------
   3. Accessibility: Focus, Skip Link, Reduced Motion
   -------------------------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  top: -200px;
  left: 1.5rem;
  z-index: 9999;
  background: var(--color-primary);
  color: #ffffff;
  padding: 0.75rem 1.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lift);
}

.skip-link:focus {
  top: 1.5rem;
}

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

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --------------------------------------------------------------------------
   4. Outer Maximum Width Container & Global Grid
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.75rem;
  padding-right: 1.75rem;
}

/* --------------------------------------------------------------------------
   5. Site Header & Brand Navigation
   -------------------------------------------------------------------------- */
header.site-header {
  background: #ffffff;
  border-top: 0;
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 0.95rem 0;
}

header.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem 2rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: var(--color-primary-dark);
}

.brand:hover {
  text-decoration: none;
}

.brand-icon, .brand svg, .brand img {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  line-height: 1.15;
  color: var(--color-primary-dark);
}

.brand-subtitle {
  font-family: var(--font-sans);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* Navigation: wraps gracefully on mobile without hamburger dependency */
nav.site-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.65rem;
}

nav.site-nav a {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  padding: 0.3rem 0;
  position: relative;
  border-bottom: 2px solid transparent;
}

nav.site-nav a:hover {
  color: var(--color-primary-dark);
  border-bottom-color: var(--color-accent);
}

nav.site-nav a[aria-current="page"],
nav.site-nav a.active {
  color: var(--color-primary-dark);
  font-weight: 600;
  border-bottom-color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   6. Typography Hierarchy & Eyebrows
   -------------------------------------------------------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.65rem;
}


h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  color: var(--color-primary-dark);
  font-feature-settings: "kern", "liga", "clig";
  text-rendering: optimizeLegibility;
}

h1 {
  font-size: clamp(2.3rem, 4.2vw, 3.4rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.025em;
  margin-bottom: 1.15rem;
}

h2 {
  font-family: var(--font-sans);
  font-size: clamp(1.65rem, 2.6vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 0.85rem;
}

h3 {
  font-family: var(--font-sans);
  font-size: clamp(1.25rem, 1.8vw, 1.55rem);
  font-weight: 600;
  line-height: 1.32;
  margin-bottom: 0.6rem;
}

h4 {
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

p {
  margin-bottom: 1.25rem;
}

p.lead, .page-lead {
  font-size: 1.2rem;
  line-height: 1.65;
  color: var(--color-text-muted);
  max-width: var(--content-width);
}

/* --------------------------------------------------------------------------
   7. Hero Component (Editorial 2-Column with Schematic)
   -------------------------------------------------------------------------- */
.hero {
  padding: 6rem 0 5.5rem;
  border-bottom: 1px solid var(--color-border);
  background: #ffffff;
}

.hero .container, .hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 4rem;
  align-items: center;
}

.hero-copy {
  display: flex;
  flex-direction: column;
}

.hero-copy h1 {
  white-space: pre-line;
  font-size: clamp(2.8rem, 4.45vw, 4rem);
  letter-spacing: -0.045em;
  margin-bottom: 1.75rem;
}

.hero-copy p {
  font-size: 1.18rem;
  line-height: 1.65;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
  max-width: 54ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0;
  background: var(--color-surface);
  padding: 0;
  overflow: hidden;
}

.hero-visual svg, .hero-visual img {
  width: 100%;
  height: auto;
  display: block;
}

/* --------------------------------------------------------------------------
   8. Buttons & Actions
   -------------------------------------------------------------------------- */
.button, a.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.72rem 1.6rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: #ffffff;
  border: 1px solid var(--color-primary-dark);
  box-shadow: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.button:hover, a.button:hover {
  background: var(--color-primary-dark);
  color: #ffffff;
  text-decoration: none;
  box-shadow: none;
}

.button-secondary, a.button-secondary {
  background: var(--color-surface);
  color: var(--color-primary);
  border: 1px solid var(--color-border-strong);
  box-shadow: none;
}

.button-secondary:hover, a.button-secondary:hover {
  background: var(--color-primary-subtle);
  color: var(--color-primary-dark);
  border-color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   9. Sections & Dividers
   -------------------------------------------------------------------------- */
.section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--color-border);
}

.section-heading {
  margin-bottom: 2.25rem;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 1.25rem;
}

.section-heading h2 {
  margin-bottom: 0;
}

.section-intro {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 60ch;
  margin-top: 0.5rem;
}

/* --------------------------------------------------------------------------
   10. Task Routes (Editorial Index Mix, Not Monotonous Rounded Cards)
   -------------------------------------------------------------------------- */
.routes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 0;
  background: var(--color-surface);
  box-shadow: var(--shadow-subtle);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.route-card {
  display: flex;
  flex-direction: column;
  padding: 1.5rem 2rem;
  position: relative;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  transition: background-color 0.2s ease;
}

.route-card:last-child {
  border-right: none;
}

.route-card:hover {
  background-color: var(--color-surface-hover);
}

.route-card .button {
  align-self: flex-start;
  padding: 0;
  border: 0;
  background: none;
  color: var(--color-accent);
  box-shadow: none;
}

.route-card .route-number {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.route-card h3 {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  margin-bottom: 0.85rem;
}

.route-card h3 a {
  color: var(--color-primary-dark);
  text-decoration: none;
}

.route-card h3 a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

.route-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1.5rem;
}

.route-card .route-action {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
}

.route-card:hover .route-action {
  color: var(--color-accent);
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   11. Resource Directory Controls (Progressive Disclosure via JS)
   -------------------------------------------------------------------------- */
#resource-controls {
  background: var(--color-surface-tint);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  margin-bottom: 2.25rem;
}

/* Hidden until revealed by JS initialization */
#resource-controls[hidden] {
  display: none !important;
}

.filter-toolbar {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.search-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.search-field label {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

input#resource-search {
  width: 100%;
  padding: 0.7rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--color-text);
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input#resource-search:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

.filter-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.filter-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.filter-label {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-right: 0.35rem;
}

button[data-filter] {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.95rem;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-muted);
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
}

button[data-filter]:hover {
  color: var(--color-primary-dark);
  border-color: var(--color-primary);
}

button[data-filter][aria-pressed="true"],
button[data-filter].is-active {
  background: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary-dark);
  font-weight: 600;
}

#resource-count {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

#no-results {
  padding: 3.5rem 2rem;
  text-align: center;
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-sm);
  margin: 2rem 0;
}

#no-results[hidden] {
  display: none !important;
}

#no-results h3 {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  margin-bottom: 0.5rem;
}

#no-results p {
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
}

/* --------------------------------------------------------------------------
   12. Resource Cards & Grid (Curated Research Directory)
   -------------------------------------------------------------------------- */
.resource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
  gap: 1.75rem;
}

.resource-card {
  min-width: 0;
  overflow-wrap: anywhere;
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 1.75rem;
  position: relative;
  box-shadow: var(--shadow-subtle);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.resource-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-lift);
}

.card-meta-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.95rem;
}

.tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border-radius: 2px;
  background: var(--color-primary-subtle);
  color: var(--color-primary-dark);
  border: 1px solid rgba(35, 35, 35, 0.15);
}

.tag[data-category="Security"], .tag-security {
  background: var(--color-accent-subtle);
  color: var(--color-accent-dark);
  border-color: rgba(37, 79, 196, 0.2);
}

.relationship-badge {
  font-size: 0.75rem;
  font-style: italic;
  color: var(--color-text-subtle);
}

.resource-card h2, .resource-card h3 {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

.resource-card h2 a, .resource-card h3 a {
  color: var(--color-primary-dark);
  text-decoration: none;
}

.resource-card h2 a:hover, .resource-card h3 a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

.resource-summary {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-muted);
  flex-grow: 1;
  margin-bottom: 1.25rem;
}

.card-meta-bottom {
  border-top: 1px solid var(--color-border-subtle);
  padding-top: 0.85rem;
  font-size: 0.82rem;
  color: var(--color-text-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.card-meta-bottom a {
  font-size: 0.82rem;
}

/* --------------------------------------------------------------------------
   13. Article Layout, Meta, Aside & Longform Typography
   -------------------------------------------------------------------------- */
.page-header {
  padding: 3.5rem 0 2rem;
  border-bottom: 2px solid var(--color-border-strong);
  margin-bottom: 3rem;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 4rem;
  align-items: start;
  margin-bottom: 4rem;
}

.article-body {
  min-width: 0;
  width: 100%;
  overflow-wrap: anywhere;
  max-width: var(--content-width);
  font-size: 1.1rem;
  line-height: 1.75;
}

.article-body p {
  margin-bottom: 1.5rem;
}

.article-body h2 {
  margin-top: 2.75rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--color-border-subtle);
}

.article-body h3 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.75rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body blockquote {
  margin: 2rem 0;
  padding: 1.25rem 1.75rem;
  border-left: 4px solid var(--color-accent);
  background: var(--color-surface-tint);
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.15rem;
  color: var(--color-primary-dark);
}

.article-aside {
  min-width: 0;
  overflow-wrap: anywhere;
  position: sticky;
  top: 5rem;
  padding: 1.5rem;
  background: var(--color-surface-tint);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
}

.article-aside h4 {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary-dark);
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--color-border);
}

.article-meta {
  list-style: none;
  padding: 0;
  margin: 0 0 1.25rem 0;
}

.article-meta dt {
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
  margin-top: 0.75rem;
}

.article-meta dd {
  margin: 0.15rem 0 0.5rem 0;
  color: var(--color-text);
}

.article-list {
  display: flex;
  flex-direction: column;
}

.article-card {
  padding: 2.25rem 0;
  border-bottom: 1px solid var(--color-border);
  display: block;
  max-width: 100%;
}

.article-card h2, .article-card h3 { max-width: 42ch; }
.article-card-header { margin-bottom: 1rem; }
.article-card-header .tag { margin-bottom: 0.75rem; }
.article-summary { max-width: 70ch; color: var(--color-text-muted); }
.article-card-meta { display: flex; flex-wrap: wrap; gap: 1.25rem; align-items: center; justify-content: space-between; }
.tags { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.section-heading { display: block; }
.section-heading .section-lead { max-width: 65ch; }
.featured-guide-card { padding: 2rem; border: 1px solid var(--color-border); border-left: 4px solid var(--color-accent); background: var(--color-surface); }
.section-footer { margin-top: 1.5rem; }
.table-wrapper { max-width: 100%; overflow-x: auto; }
.table-wrapper table { min-width: 560px; }
.table-wrapper th[scope="row"] { width: 24%; min-width: 8rem; text-transform: none; letter-spacing: 0; overflow-wrap: normal; }
.article-body th, .article-body td { overflow-wrap: normal; }
.article-body th[scope="row"] { white-space: nowrap; }
.article-body > .section { padding: 0 0 1.25rem; }
.article-body > .section:first-child h2 { margin-top: 0; }
.article-body pre { max-width: 100%; }
.resource-meta, .source-list { overflow-wrap: anywhere; }

.article-card-date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-subtle);
}

.article-card-body h3 {
  font-family: var(--font-sans);
  font-size: 1.45rem;
  margin-bottom: 0.6rem;
}

.article-card-body p {
  color: var(--color-text-muted);
  margin-bottom: 0.85rem;
}

/* --------------------------------------------------------------------------
   14. Tables, Code, Worksheets, Callouts, & Citations
   -------------------------------------------------------------------------- */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  font-size: 0.92rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

th {
  background: var(--color-surface-tint);
  color: var(--color-primary-dark);
  font-weight: 700;
  text-align: left;
  padding: 0.85rem 1.1rem;
  border-bottom: 2px solid var(--color-border-strong);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

td {
  padding: 0.85rem 1.1rem;
  border-bottom: 1px solid var(--color-border-subtle);
  vertical-align: top;
}

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

tr:nth-child(even) td {
  background: rgba(35, 35, 35, 0.015);
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border-subtle);
  padding: 0.15rem 0.35rem;
  border-radius: 2px;
  color: var(--color-primary-dark);
}

pre {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background: #191919;
  color: #f5f5f5;
  border: 1px solid var(--color-primary-dark);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.75rem 0;
  line-height: 1.6;
  position: relative;
}

pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: inherit;
  font-size: inherit;
}

/* Copy button for practical guide worksheets */
.copy-button {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #f5f5f5;
  padding: 0.3rem 0.65rem;
  border-radius: 3px;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.copy-button:hover {
  background: rgba(255, 255, 255, 0.25);
}

.copy-button.is-copied {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #ffffff;
}

.callout {
  margin: 2rem 0;
  padding: 1.35rem 1.65rem;
  background: var(--color-surface-tint);
  border-left: 4px solid var(--color-primary);
  border-top: 1px solid var(--color-border-subtle);
  border-right: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.callout-rust {
  border-left-color: var(--color-accent);
  background: var(--color-accent-subtle);
}

.callout p:last-child {
  margin-bottom: 0;
}

.source-list {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
}

.source-list li {
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.75rem;
  font-size: 0.92rem;
  color: var(--color-text-muted);
}

.source-list li::before {
  content: "\2022";
  position: absolute;
  left: 0.25rem;
  color: var(--color-accent);
  font-weight: bold;
}

/* --------------------------------------------------------------------------
   15. Site Footer
   -------------------------------------------------------------------------- */
footer.site-footer {
  margin-top: auto;
  background: #191919;
  color: #d6d6d6;
  border-top: 1px solid var(--color-border);
  padding: 4rem 0 2.5rem;
  font-size: 0.92rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1.2fr 1fr;
  gap: 3.5rem;
  margin-bottom: 3rem;
}

.footer-col h2 {
  font-family: var(--font-sans);
  font-size: 1.15rem;
  color: #ffffff;
  margin-bottom: 1rem;
}

.footer-col p {
  line-height: 1.6;
  margin-bottom: 1rem;
  color: #bcbcbc;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col li {
  margin-bottom: 0.6rem;
}

.footer-col a {
  color: #d6d6d6;
  text-decoration: none;
  transition: color 0.15s ease;
}

.footer-col a:hover {
  color: #ffffff;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.82rem;
  color: #a5a5a5;
}

.footer-bottom a {
  color: #bcbcbc;
}

/* --------------------------------------------------------------------------
   16. Responsive Media Queries
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
  .hero .container, .hero-layout {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .hero-visual {
    max-width: 650px;
    margin: 0 auto;
  }

  .routes {
    grid-template-columns: 1fr;
  }

  .route-card {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }

  .route-card:last-child {
    border-bottom: none;
  }

  .article-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .article-aside {
    position: static;
    order: 1;
    margin-bottom: 2.5rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 680px) {
  [id] { scroll-margin-top: 13rem; }

  .container {
    padding-left: 1.15rem;
    padding-right: 1.15rem;
  }

  .hero {
    padding: 2.75rem 0 2.25rem;
  }

  .section {
    padding: 2.75rem 0;
  }

  header.site-header .container {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  nav.site-nav {
    width: 100%;
    justify-content: flex-start;
    gap: 0.5rem 1rem;
  }

  .article-card {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .resource-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .filter-row {
    flex-direction: column;
    align-items: flex-start;
  }
}