/* ==========================================================================
   STYLE.CSS
   The reusable component library shared by every page on the site.
   Rules:
     1. No page-specific selectors (no #home-hero, no .bmi-calculator-form).
     2. Every component is a standalone, composable class (BEM-ish naming).
     3. Mobile-first: base rules target small screens; responsive.css layers
        on min-width overrides for larger viewports.
     4. Every color/space/font value comes from variables.css.

   TABLE OF CONTENTS
     1.  Reset & Base
     2.  Typography
     3.  Layout & Containers
     4.  Header & Navigation
     5.  Breadcrumbs
     6.  Search Box
     7.  Buttons
     8.  Cards
     9.  Tool Card
     10. Category Card
     11. Tables
     12. Forms
     13. Alerts
     14. FAQ / Accordion
     15. Code Block
     16. Share / Copy / Print Buttons
     17. Scroll To Top Button
     18. Footer
     19. Utilities
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. RESET & BASE
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

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

body {
  margin: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--transition-base), color var(--transition-base);
}

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

img {
  aspect-ratio: attr(width) / attr(height);
}

a {
  color: var(--color-link);
  text-decoration: none;
}

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

ul,
ol {
  padding-left: var(--space-5);
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
}

hr {
  border: none;
  border-top: var(--border-width) solid var(--color-border);
  margin: var(--space-6) 0;
}

/* Consistent, visible keyboard focus everywhere */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

/* --------------------------------------------------------------------------
   2. TYPOGRAPHY
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--fw-semibold);
  line-height: var(--lh-tight);
  color: var(--color-text);
  margin: 0 0 var(--space-4);
}

h1 { font-size: var(--fs-2xl); }
h2 { font-size: var(--fs-xl); }
h3 { font-size: var(--fs-lg); }
h4 { font-size: var(--fs-md); }
h5, h6 { font-size: var(--fs-base); }

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

.text-muted   { color: var(--color-text-muted); }
.text-subtle  { color: var(--color-text-subtle); }
.text-mono    { font-family: var(--font-mono); }

.lede {
  font-size: var(--fs-md);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
}

/* Signature "ruler" divider — a hairline rule with tick marks.
   Used under section headings across the site (category pages, tool
   pages, article intros) as the recurring visual signature. */
.rule-ticks {
  height: 8px;
  margin: var(--space-2) 0 var(--space-6);
  background-image: repeating-linear-gradient(
    to right,
    var(--color-tick) 0,
    var(--color-tick) 1px,
    transparent 1px,
    transparent 12px
  );
  background-position: bottom left;
  background-size: 100% 8px;
  background-repeat: repeat-x;
  border-bottom: var(--border-width) solid var(--color-border);
}

/* --------------------------------------------------------------------------
   3. LAYOUT & CONTAINERS
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.page-main {
  min-height: 60vh;
  padding-block: var(--space-6);
}

/* Simple flex/grid helpers used across component layouts */
.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
}

.grid {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: 1fr;
}

/* --------------------------------------------------------------------------
   4. HEADER & NAVIGATION
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background-color: var(--color-surface);
  border-bottom: var(--border-width) solid var(--color-border);
  transition: box-shadow var(--transition-base);
}

.site-header.is-scrolled {
  box-shadow: var(--shadow-sm);
}

.site-header__bar {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  height: var(--header-height);
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  font-size: var(--fs-md);
  color: var(--color-text);
  white-space: nowrap;
  flex-shrink: 0;
}

.site-logo:hover {
  color: var(--color-text);
  text-decoration: none;
}

.site-logo__mark {
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  flex-shrink: 0;
}

/* Nav sits in a scrollable/collapsible drawer on mobile, inline on desktop.
   Mobile-first: hidden by default, toggled open by navigation.js. */
.site-nav {
  position: fixed;
  inset: var(--header-height) 0 0 0;
  background-color: var(--color-surface);
  padding: var(--space-5) var(--space-4);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  z-index: var(--z-header);
}

.site-nav.is-open {
  transform: translateX(0);
}

.site-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.site-nav__link {
  display: block;
  padding: var(--space-3) var(--space-2);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-weight: var(--fw-medium);
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"] {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-left: auto;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  flex-shrink: 0;
}

.nav-toggle__icon,
.nav-toggle__icon::before,
.nav-toggle__icon::after {
  display: block;
  width: 18px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
  position: relative;
}

.nav-toggle__icon::before { content: ""; position: absolute; top: -6px; }
.nav-toggle__icon::after  { content: ""; position: absolute; top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__icon {
  background-color: transparent;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::before {
  transform: translateY(6px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::after {
  transform: translateY(-6px) rotate(-45deg);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-full);
  background-color: var(--color-surface);
  color: var(--color-text);
  flex-shrink: 0;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--color-border-strong);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

/* --------------------------------------------------------------------------
   5. BREADCRUMBS
   -------------------------------------------------------------------------- */
.breadcrumbs {
  padding-block: var(--space-3);
}

.breadcrumbs__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  font-size: var(--fs-sm);
  color: var(--color-text-subtle);
}

.breadcrumbs__list li {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.breadcrumbs__list li:not(:last-child)::after {
  content: "/";
  color: var(--color-text-subtle);
  margin-left: var(--space-1);
}

.breadcrumbs__list a {
  color: var(--color-text-muted);
}

.breadcrumbs__list [aria-current="page"] {
  color: var(--color-text);
  font-weight: var(--fw-medium);
}

/* --------------------------------------------------------------------------
   6. SEARCH BOX
   -------------------------------------------------------------------------- */
.search-box {
  position: relative;
  width: 100%;
}

.search-box__field {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-surface-muted);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-full);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-box__field:focus-within {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-focus);
  background-color: var(--color-surface);
}

.search-box__icon {
  width: 18px;
  height: 18px;
  color: var(--color-text-subtle);
  flex-shrink: 0;
}

.search-box__input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: var(--fs-sm);
  color: var(--color-text);
  outline: none;
  min-width: 0;
}

.search-box__input::placeholder {
  color: var(--color-text-subtle);
}

.search-box__results {
  position: absolute;
  top: calc(100% + var(--space-2));
  left: 0;
  right: 0;
  background-color: var(--color-surface-raised);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 340px;
  overflow-y: auto;
  z-index: var(--z-dropdown);
  display: none;
}

.search-box__results.is-open {
  display: block;
}

.search-box__result {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: var(--space-3);
  border-bottom: var(--border-width) solid var(--color-border);
  color: var(--color-text);
}

.search-box__result:last-child { border-bottom: none; }

.search-box__result:hover,
.search-box__result.is-active {
  background-color: var(--color-primary-soft);
  text-decoration: none;
}

.search-box__result-title {
  font-weight: var(--fw-medium);
  font-size: var(--fs-sm);
}

.search-box__result-category {
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
}

.search-box__empty {
  padding: var(--space-4);
  text-align: center;
  font-size: var(--fs-sm);
  color: var(--color-text-subtle);
}

/* --------------------------------------------------------------------------
   7. BUTTONS
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-body);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  line-height: 1;
  border-radius: var(--radius-sm);
  border: var(--border-width) solid transparent;
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
}

.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
  pointer-events: none;
}

.btn--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: #FFFFFF;
}
.btn--primary:hover {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: #FFFFFF;
}

.btn--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: #FFFFFF;
}
.btn--accent:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: #FFFFFF;
}

.btn--secondary {
  background-color: var(--color-surface);
  border-color: var(--color-border-strong);
  color: var(--color-text);
}
.btn--secondary:hover {
  background-color: var(--color-surface-muted);
  color: var(--color-text);
}

.btn--ghost {
  background-color: transparent;
  border-color: transparent;
  color: var(--color-primary);
}
.btn--ghost:hover {
  background-color: var(--color-primary-soft);
}

.btn--danger {
  background-color: var(--color-danger);
  border-color: var(--color-danger);
  color: #FFFFFF;
}

.btn--sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--fs-xs);
}

.btn--lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--fs-base);
}

.btn--block {
  width: 100%;
}

.btn--icon {
  padding: var(--space-2);
  width: 38px;
  height: 38px;
}

.btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   8. CARDS
   -------------------------------------------------------------------------- */
.card {
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base),
    border-color var(--transition-base);
}

.card--hoverable:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--color-border-strong);
}

.card__title {
  font-size: var(--fs-md);
  margin-bottom: var(--space-2);
}

.card__body {
  color: var(--color-text-muted);
}

.card__footer {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: var(--border-width) solid var(--color-border);
}

/* --------------------------------------------------------------------------
   9. TOOL CARD
   The primary link unit for an individual calculator/converter/tool.
   -------------------------------------------------------------------------- */
.tool-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  color: var(--color-text);
  transition: box-shadow var(--transition-base), transform var(--transition-base),
    border-color var(--transition-base);
}

.tool-card:hover {
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--color-primary);
}

.tool-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  flex-shrink: 0;
}

.tool-card__icon svg {
  width: 22px;
  height: 22px;
}

.tool-card__title {
  font-family: var(--font-display);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  margin: 0;
}

.tool-card__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin: 0;
  line-height: var(--lh-relaxed);
}

.tool-card__meta {
  margin-top: auto;
  padding-top: var(--space-2);
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* --------------------------------------------------------------------------
   10. CATEGORY CARD
   Larger, used on the homepage/category index to link to whole sections.
   -------------------------------------------------------------------------- */
.category-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  color: var(--color-text);
  transition: box-shadow var(--transition-base), transform var(--transition-base),
    border-color var(--transition-base);
}

.category-card:hover {
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: var(--color-accent);
}

.category-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-primary-soft), var(--color-accent-soft));
  color: var(--color-primary);
  flex-shrink: 0;
}

.category-card__icon svg {
  width: 28px;
  height: 28px;
}

.category-card__title {
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  margin: 0 0 var(--space-1);
}

.category-card__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin: 0 0 var(--space-2);
}

.category-card__count {
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* --------------------------------------------------------------------------
   11. TABLES
   -------------------------------------------------------------------------- */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-sm);
  min-width: 480px;
}

.table caption {
  text-align: left;
  padding: var(--space-3);
  color: var(--color-text-muted);
  font-size: var(--fs-xs);
}

.table th,
.table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: var(--border-width) solid var(--color-border);
}

.table thead th {
  background-color: var(--color-surface-muted);
  font-family: var(--font-display);
  font-weight: var(--fw-semibold);
  color: var(--color-text);
  white-space: nowrap;
}

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

.table tbody tr:hover {
  background-color: var(--color-primary-soft);
}

.table--numeric td {
  font-family: var(--font-mono);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.table--striped tbody tr:nth-child(even) {
  background-color: var(--color-surface-muted);
}

/* --------------------------------------------------------------------------
   12. FORMS
   -------------------------------------------------------------------------- */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text);
}

.form-label .is-optional {
  font-weight: var(--fw-regular);
  color: var(--color-text-subtle);
}

.form-hint {
  margin-top: var(--space-2);
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
}

.form-control {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: var(--fs-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:hover {
  border-color: var(--color-text-subtle);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-focus);
}

.form-control::placeholder {
  color: var(--color-text-subtle);
}

.form-control[aria-invalid="true"] {
  border-color: var(--color-danger);
}

select.form-control {
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%),
    linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: calc(100% - 18px) center, calc(100% - 13px) center;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: var(--space-8);
}

.form-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.form-row > .form-group {
  flex: 1 1 200px;
}

.input-group {
  display: flex;
}

.input-group .form-control {
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}

.input-group__addon {
  display: flex;
  align-items: center;
  padding: 0 var(--space-4);
  background-color: var(--color-surface-muted);
  border: var(--border-width) solid var(--color-border-strong);
  border-left: none;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  white-space: nowrap;
}

.checkbox-field,
.radio-field {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-sm);
}

.checkbox-field input,
.radio-field input {
  width: 18px;
  height: 18px;
  accent-color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   13. ALERTS
   -------------------------------------------------------------------------- */
.alert {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4);
  border: var(--border-width) solid transparent;
  border-left-width: 4px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
}

.alert__icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.alert__title {
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-1);
}

.alert--info {
  background-color: var(--color-info-soft);
  border-color: var(--color-info);
  color: var(--color-text);
}

.alert--success {
  background-color: var(--color-success-soft);
  border-color: var(--color-success);
  color: var(--color-text);
}

.alert--warning {
  background-color: var(--color-warning-soft);
  border-color: var(--color-warning);
  color: var(--color-text);
}

.alert--danger {
  background-color: var(--color-danger-soft);
  border-color: var(--color-danger);
  color: var(--color-text);
}

/* --------------------------------------------------------------------------
   14. FAQ / ACCORDION
   -------------------------------------------------------------------------- */
.faq {
  border-top: var(--border-width) solid var(--color-border);
}

.faq-item {
  border-bottom: var(--border-width) solid var(--color-border);
}

.faq-item__question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  background: none;
  border: none;
  text-align: left;
  font-family: var(--font-display);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  color: var(--color-text);
}

.faq-item__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  color: var(--color-text-subtle);
  transition: transform var(--transition-base);
}

.faq-item__question[aria-expanded="true"] .faq-item__icon {
  transform: rotate(45deg);
  color: var(--color-accent);
}

.faq-item__answer {
  overflow: hidden;
  max-height: 0;
  transition: max-height var(--transition-slow) ease;
}

.faq-item__answer-inner {
  padding-bottom: var(--space-4);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
}

/* --------------------------------------------------------------------------
   15. CODE BLOCK
   -------------------------------------------------------------------------- */
.code-block {
  position: relative;
  background-color: var(--color-surface-muted);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.code-block__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-4);
  background-color: var(--color-surface);
  border-bottom: var(--border-width) solid var(--color-border);
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.code-block pre {
  margin: 0;
  padding: var(--space-4);
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-text);
  line-height: var(--lh-relaxed);
}

/* Inline code (outside a code-block) */
:not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background-color: var(--color-surface-muted);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

/* --------------------------------------------------------------------------
   16. SHARE / COPY / PRINT BUTTONS
   Generic action-bar used on tool & article pages.
   -------------------------------------------------------------------------- */
.action-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background-color: var(--color-surface);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  transition: background-color var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast);
}

.action-btn:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.action-btn svg {
  width: 15px;
  height: 15px;
}

.action-btn.is-success {
  background-color: var(--color-success-soft);
  color: var(--color-success);
  border-color: var(--color-success);
}

.share-menu {
  position: relative;
  display: inline-flex;
}

.share-menu__panel {
  position: absolute;
  top: calc(100% + var(--space-2));
  right: 0;
  display: none;
  gap: var(--space-1);
  padding: var(--space-2);
  background-color: var(--color-surface-raised);
  border: var(--border-width) solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-dropdown);
}

.share-menu__panel.is-open {
  display: flex;
}

.share-menu__link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}

.share-menu__link:hover {
  background-color: var(--color-surface-muted);
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   17. SCROLL TO TOP BUTTON
   -------------------------------------------------------------------------- */
.scroll-top-btn {
  position: fixed;
  right: var(--space-4);
  bottom: var(--space-4);
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-primary);
  color: #FFFFFF;
  border: none;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--transition-base), transform var(--transition-base),
    visibility var(--transition-base), background-color var(--transition-fast);
  z-index: var(--z-header);
}

.scroll-top-btn.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  background-color: var(--color-primary-hover);
}

.scroll-top-btn svg {
  width: 20px;
  height: 20px;
}

/* --------------------------------------------------------------------------
   18. FOOTER
   -------------------------------------------------------------------------- */
.site-footer {
  margin-top: var(--space-10);
  background-color: var(--color-surface);
  border-top: var(--border-width) solid var(--color-border);
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}

.site-footer__top {
  display: grid;
  gap: var(--space-6);
  padding-block: var(--space-8);
  grid-template-columns: 1fr;
}

.site-footer__brand {
  max-width: 320px;
}

.site-footer__tagline {
  margin-top: var(--space-2);
  color: var(--color-text-subtle);
  line-height: var(--lh-relaxed);
}

.site-footer__heading {
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.site-footer__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-footer__list a {
  color: var(--color-text-muted);
}

.site-footer__list a:hover {
  color: var(--color-primary);
}

.site-footer__socials {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.site-footer__social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  border: var(--border-width) solid var(--color-border);
  color: var(--color-text-muted);
}

.site-footer__social-link:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
}

.site-footer__social-link svg {
  width: 16px;
  height: 16px;
}

.site-footer__bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-block: var(--space-5);
  border-top: var(--border-width) solid var(--color-border);
  font-size: var(--fs-xs);
  color: var(--color-text-subtle);
}

/* --------------------------------------------------------------------------
   19. UTILITIES
   -------------------------------------------------------------------------- */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -60px;
  background-color: var(--color-primary);
  color: #FFFFFF;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
  color: #FFFFFF;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
}