/* ==========================================================================
   components.css — All 22 reusable UI components
   aiengineer.hu
   Index:
    1. Navbar        2. Chapter card   3. Callout       4. Badge
    5. TOC           6. Chapter nav    7. Feature grid  8. Progress bar
    9. Sidebar       10. Hero          11. Button       12. Footer
    13. Search modal 14. Roadmap node  15. Level card   16. Skip nav
    17. Toast        18. Code block    19. Data table   20. Collapsible TOC
    21. Breadcrumb   22. Related chapters
   ========================================================================== */

/* ==========================================================================
   16. Skip navigation (first for a11y)
   ========================================================================== */
.skip-nav {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  z-index: var(--z-toast);
  padding: var(--space-3) var(--space-5);
  background: var(--color-text-light, var(--text-primary));
  color: var(--color-text-dark, var(--text-inverse));
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: var(--font-normal);
  letter-spacing: var(--tracking-wide);
  transition: top var(--transition-base);
}

.skip-nav:focus {
  top: var(--space-3);
  color: var(--color-text-dark, var(--text-inverse));
}

/* ==========================================================================
   1. Navbar
   ========================================================================== */
.navbar {
  position: sticky;
  top: 0;
  z-index: var(--z-navbar);
  height: var(--nav-height);
  background: var(--glass-bg);
  backdrop-filter: var(--blur-md);
  -webkit-backdrop-filter: var(--blur-md);
  border-bottom: 1px solid var(--glass-border);
  transition: transform 0.3s ease, background 0.3s ease;
}

.navbar--hidden {
  transform: translateY(-100%);
}

.navbar__container {
  max-width: var(--container-xl);
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.navbar__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: var(--font-medium);
  font-size: var(--text-sm);
  color: var(--text-primary);
  white-space: nowrap;
  font-family: var(--font-mono);
  letter-spacing: var(--tracking-wide);
}

.navbar__brand:hover { color: var(--text-primary); }

.navbar__logo {
  width: 26px;
  height: 26px;
  color: var(--accent-primary);
}

.navbar__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: 1px solid var(--surface-border-hover);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  color: var(--text-primary);
  flex-shrink: 0;
}

.navbar__wordmark {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 400;
  letter-spacing: var(--tracking-wide);
}

@media (max-width: 480px) {
  .navbar__wordmark { display: none; }
}

.navbar__nav {
  display: none;
  align-items: center;
  gap: var(--space-2);
  margin-right: auto;
}

@media (min-width: 900px) {
  .navbar__nav { display: flex; }
}

.navbar__link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  font-weight: var(--font-normal);
  font-family: var(--font-mono);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  border-radius: var(--radius-none);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.navbar__link:hover {
  color: var(--text-primary);
  background: transparent;
}

.navbar__link--active {
  color: var(--text-primary);
  position: relative;
}

.navbar__link--active::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: -2px;
  height: 1px;
  background: var(--accent-primary);
  border-radius: 0;
}

.navbar__chevron {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-fast);
}

/* Dropdown */
.navbar__dropdown {
  position: relative;
}

.navbar__dropdown-trigger[aria-expanded="true"] .navbar__chevron {
  transform: rotate(180deg);
}

.navbar__dropdown-content {
  position: absolute;
  top: calc(100% + var(--space-3));
  left: 0;
  z-index: var(--z-dropdown);
  min-width: 540px;
  padding: var(--space-4);
  display: none;
  gap: var(--space-6);
  background: var(--bg-elevated);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-none);
  box-shadow: var(--shadow-lg);
}

.navbar__dropdown-content::before {
  content: "";
  position: absolute;
  top: calc(-1 * var(--space-3));
  left: 0;
  right: 0;
  height: var(--space-3);
}

.navbar__dropdown.is-open .navbar__dropdown-content {
  display: flex;
}

.navbar__dropdown-col {
  flex: 1;
  min-width: 0;
}

.navbar__dropdown-heading {
  display: block;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--text-tertiary);
  padding: var(--space-2) var(--space-3);
  font-weight: var(--font-semibold);
}

.navbar__dropdown-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.navbar__dropdown-link:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.navbar__dropdown-status {
  color: var(--text-tertiary);
  font-size: var(--text-sm);
  flex-shrink: 0;
}

.navbar__dropdown-link.is-complete .navbar__dropdown-status {
  color: var(--color-success);
}

.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}

.btn--nav {
  display: none;
  padding: 0.55rem 1.1rem;
  font-size: var(--text-xs);
}

@media (min-width: 900px) {
  .btn--nav { display: inline-flex; }
}

.navbar__search,
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.navbar__search:hover,
.theme-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.navbar__search svg,
.theme-toggle svg {
  width: 20px;
  height: 20px;
}

/* Theme toggle icon swap */
.theme-toggle__icon {
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.theme-toggle__icon--light { display: none; }
[data-theme="light"] .theme-toggle__icon--dark { display: none; }
[data-theme="light"] .theme-toggle__icon--light { display: block; }

/* Hamburger */
.navbar__hamburger {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 0 9px;
  border-radius: var(--radius-md);
}

@media (min-width: 900px) {
  .navbar__hamburger { display: none; }
}

.navbar__hamburger span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--text-primary);
  border-radius: var(--radius-full);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.navbar--open .navbar__hamburger span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.navbar--open .navbar__hamburger span:nth-child(2) {
  opacity: 0;
}
.navbar--open .navbar__hamburger span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile slide-in menu */
.mobile-menu {
  position: fixed;
  inset: var(--nav-height) 0 0 0;
  z-index: var(--z-navbar);
  background: var(--bg-primary);
  padding: var(--space-6);
  overflow-y: auto;
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  visibility: hidden;
}

.navbar--open ~ .mobile-menu,
.mobile-menu.is-open {
  transform: translateX(0);
  visibility: visible;
}

@media (min-width: 900px) {
  .mobile-menu { display: none; }
}

.mobile-menu__link {
  display: block;
  padding: var(--space-3) var(--space-2);
  font-size: var(--text-lg);
  font-weight: var(--font-medium);
  color: var(--text-primary);
  border-bottom: 1px solid var(--surface-border);
}

.mobile-menu__section-title {
  margin-top: var(--space-4);
  margin-bottom: var(--space-2);
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--text-tertiary);
}

.mobile-menu__chapters {
  display: grid;
  gap: var(--space-1);
}

.mobile-menu__chapter {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
}

.mobile-menu__chapter:hover { background: var(--bg-tertiary); color: var(--text-primary); }
.mobile-menu__chapter .navbar__dropdown-status { color: var(--text-tertiary); }
.mobile-menu__chapter.is-complete .navbar__dropdown-status { color: var(--color-success); }

/* ==========================================================================
   11. Button
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.75rem 1.35rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-weight: var(--font-normal);
  font-size: var(--text-sm);
  letter-spacing: var(--tracking-wide);
  line-height: 1;
  text-align: center;
  white-space: nowrap;
  cursor: pointer;
  position: relative;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast),
    transform var(--transition-fast),
    text-shadow var(--transition-fast);
  border: 1px solid var(--surface-border-hover);
  background: transparent;
  color: var(--text-primary);
  min-height: 44px;
}

.btn:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
}

.btn:active { transform: translateY(1px); }

/* Primary = thin-frame outline (engraving × terminal) */
.btn--primary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid color-mix(in srgb, var(--text-primary) 70%, transparent);
  box-shadow: none;
}
.btn--primary:hover {
  background: color-mix(in srgb, var(--text-primary) 6%, transparent);
  border-color: var(--text-primary);
  color: var(--text-primary);
  box-shadow: none;
}

@media (prefers-reduced-motion: no-preference) {
  .btn--primary:hover {
    text-shadow:
      1px 0 color-mix(in srgb, var(--accent-primary) 45%, transparent),
      -1px 0 color-mix(in srgb, var(--color-accent-blue, #6b7f96) 45%, transparent);
  }
}

[data-theme="light"] .btn--primary {
  background: transparent;
  color: var(--text-primary);
  border-color: color-mix(in srgb, var(--text-primary) 55%, transparent);
}
[data-theme="light"] .btn--primary:hover {
  background: color-mix(in srgb, var(--text-primary) 5%, transparent);
  color: var(--text-primary);
}

.btn--secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--surface-border-hover);
  border-radius: var(--radius-sm);
}
.btn--secondary:hover { background: var(--bg-tertiary); color: var(--text-primary); }

.btn--ghost {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--surface-border-hover);
  border-radius: var(--radius-sm);
}
.btn--ghost:hover { background: var(--bg-tertiary); color: var(--text-primary); }

.btn--sm { padding: 0.5rem 0.9rem; font-size: var(--text-xs); min-height: 36px; }
.btn--lg { padding: 0.9rem 1.6rem; font-size: var(--text-sm); min-height: 48px; }

/* ==========================================================================
   4. Badge
   ========================================================================== */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-none);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--font-normal);
  text-transform: uppercase;
  letter-spacing: var(--tracking-mono);
  white-space: nowrap;
}

.badge--alapszint { background: color-mix(in srgb, var(--level-alapszint) 15%, transparent); color: var(--level-alapszint); }
.badge--piackepes { background: color-mix(in srgb, var(--level-piackepes) 15%, transparent); color: var(--level-piackepes); }
.badge--senior    { background: color-mix(in srgb, var(--level-senior) 18%, transparent); color: var(--level-senior); }
.badge--platform  { background: color-mix(in srgb, var(--level-platform) 15%, transparent); color: var(--level-platform); }

/* ==========================================================================
   10. Hero
   ========================================================================== */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding: var(--space-24) var(--space-5);
}

/* Homepage engraving hero overrides base centering via home.css */

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, var(--surface-border) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 75%);
  opacity: 0.6;
}

.hero__blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
  will-change: transform;
}

.hero__blob--1 {
  width: 480px; height: 480px;
  background: radial-gradient(circle, #6366f1, transparent 70%);
  top: -120px; left: -80px;
  animation: blob-float-1 22s ease-in-out infinite;
}
.hero__blob--2 {
  width: 420px; height: 420px;
  background: radial-gradient(circle, #8b5cf6, transparent 70%);
  bottom: -140px; right: -60px;
  animation: blob-float-2 26s ease-in-out infinite;
}
.hero__blob--3 {
  width: 360px; height: 360px;
  background: radial-gradient(circle, #a78bfa, transparent 70%);
  top: 30%; left: 55%;
  animation: blob-float-3 30s ease-in-out infinite;
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 820px;
}

.hero__badge {
  display: inline-block;
  padding: var(--space-2) var(--space-4);
  margin-bottom: var(--space-6);
  border-radius: var(--radius-full);
  background: var(--accent-muted);
  border: 1px solid var(--surface-border);
  color: var(--accent-hover);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  letter-spacing: var(--tracking-wide);
}

.hero__title {
  font-size: var(--text-5xl);
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  margin-bottom: var(--space-6);
}

.hero__title--gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero__subtitle {
  font-size: var(--text-xl);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
  margin-bottom: var(--space-8);
  max-width: 640px;
  margin-inline: auto;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: center;
}

/* ==========================================================================
   Stats strip
   ========================================================================== */
.stats {
  border-block: 1px solid var(--surface-border);
  background: var(--bg-secondary);
}

.stats__inner {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
  padding-block: var(--space-10);
  text-align: center;
}

@media (min-width: 768px) {
  .stats__inner { grid-template-columns: repeat(4, 1fr); }
}

.stat__number {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  line-height: 1.1;
}

.stat__label {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

/* ==========================================================================
   2. Chapter card
   ========================================================================== */
.chapter-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-6);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  overflow: hidden;
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth),
    border-color var(--transition-smooth);
}

.chapter-card:hover {
  transform: translateY(-4px);
  border-color: var(--chapter-color, var(--accent-primary));
  box-shadow: var(--shadow-lg);
  color: inherit;
}

.chapter-card__number {
  position: absolute;
  top: var(--space-2);
  right: var(--space-4);
  font-size: 3.5rem;
  font-weight: var(--font-bold);
  line-height: 1;
  color: var(--chapter-color, var(--accent-primary));
  opacity: 0.14;
  font-family: var(--font-mono);
  pointer-events: none;
}

.chapter-card__content { position: relative; z-index: 1; flex: 1; }

.chapter-card__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.chapter-card__desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
}

.chapter-card__meta {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: auto;
}

.chapter-card__status {
  color: var(--color-success);
  font-weight: var(--font-bold);
}

.chapter-card__glow {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0;
  background: radial-gradient(circle at 70% 0%, var(--chapter-color, var(--accent-primary)), transparent 60%);
  transition: opacity var(--transition-smooth);
  pointer-events: none;
}

.chapter-card:hover .chapter-card__glow { opacity: 0.12; }

/* ==========================================================================
   Levels preview (landing) — horizontal cards
   ========================================================================== */
.levels-strip {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

@media (min-width: 640px) { .levels-strip { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .levels-strip { grid-template-columns: repeat(4, 1fr); } }

.level-chip {
  padding: var(--space-5);
  border: 1px solid var(--surface-border);
  border-top: 3px solid var(--level-color, var(--accent-primary));
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.level-chip:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.level-chip__emoji { font-size: var(--text-2xl); }
.level-chip__title { font-size: var(--text-lg); font-weight: var(--font-semibold); margin: var(--space-2) 0; color: var(--text-primary); }
.level-chip__desc { font-size: var(--text-sm); color: var(--text-secondary); }

/* ==========================================================================
   CTA final section
   ========================================================================== */
.cta-final {
  text-align: center;
}
.cta-final__box {
  position: relative;
  padding: var(--space-16) var(--space-6);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(var(--bg-secondary), var(--bg-secondary)) padding-box,
    var(--accent-gradient) border-box;
  border: 1px solid transparent;
  overflow: hidden;
}
.cta-final__title { font-size: var(--text-3xl); font-weight: var(--font-bold); margin-bottom: var(--space-4); }
.cta-final__text { color: var(--text-secondary); font-size: var(--text-lg); margin-bottom: var(--space-8); max-width: 520px; margin-inline: auto; }

/* ==========================================================================
   3. Callout
   ========================================================================== */
.callout {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  margin-block: var(--space-6);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  border-left: 3px solid var(--callout-color, var(--accent-primary));
  background: color-mix(in srgb, var(--callout-color, var(--accent-primary)) 8%, transparent);
}

.callout__icon {
  flex-shrink: 0;
  color: var(--callout-color, var(--accent-primary));
  display: flex;
}
.callout__icon svg { width: 22px; height: 22px; }

.callout__content { color: var(--text-secondary); }
.callout__content p { margin: 0; }
.callout__content p + p { margin-top: var(--space-2); }
.callout__content strong { color: var(--text-primary); }

.callout--note      { --callout-color: var(--color-info); }
.callout--important { --callout-color: var(--accent-primary); }
.callout--rule      { --callout-color: var(--color-warning); }
.callout--quote     { --callout-color: var(--text-secondary); font-style: italic; }

/* ==========================================================================
   7. Feature grid
   ========================================================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--space-4);
  list-style: none;
  padding: 0;
  margin-block: var(--space-6);
}

.feature-grid__item {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-4);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.feature-grid__item:hover {
  background: var(--bg-tertiary);
  border-color: var(--surface-border-hover);
}

.feature-grid__label {
  font-weight: var(--font-semibold);
  color: var(--text-primary);
}

.feature-grid__desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.feature-grid__icon { width: 20px; height: 20px; color: var(--accent-primary); }

/* ==========================================================================
   8. Reading progress bar
   ========================================================================== */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: var(--z-progress);
  background: transparent;
}

.progress-bar__fill {
  height: 100%;
  width: var(--progress, 0%);
  background: var(--chapter-color, var(--accent-primary));
  transition: width 0.1s linear;
}

/* summary bar (landing/roadmap) uses gradient */
.progress-summary {
  margin-block: var(--space-6);
}
.progress-summary__label {
  display: flex;
  justify-content: space-between;
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}
.progress-summary__track {
  height: 2px;
  border-radius: 0;
  background: var(--bg-tertiary);
  overflow: hidden;
}
.progress-summary__fill {
  height: 100%;
  width: var(--progress, 0%);
  background: var(--accent-primary);
  border-radius: 0;
  transition: width 0.4s var(--ease-out, ease);
}

/* ==========================================================================
   9. Sidebar
   ========================================================================== */
.sidebar {
  position: sticky;
  top: var(--nav-height);
  height: calc(100vh - var(--nav-height));
  overflow-y: auto;
  padding: var(--space-6) var(--space-4);
  border-right: 1px solid var(--surface-border);
  scrollbar-width: thin;
}

.sidebar__title {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--text-tertiary);
  padding-inline: var(--space-3);
  margin-bottom: var(--space-3);
}

.sidebar__list { list-style: none; display: grid; gap: 2px; }

.sidebar__link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  border-left: 2px solid transparent;
  font-size: var(--text-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.sidebar__link:hover { background: var(--bg-tertiary); color: var(--text-primary); }

.sidebar__item--active .sidebar__link {
  background: var(--accent-muted);
  color: var(--text-primary);
  border-left-color: var(--accent-primary);
  font-weight: var(--font-medium);
}

.sidebar__number {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.sidebar__item--active .sidebar__number { color: var(--accent-primary); }

.sidebar__title-text { flex: 1; }

.sidebar__check {
  flex-shrink: 0;
  color: var(--color-success);
  font-weight: var(--font-bold);
  font-size: var(--text-sm);
}

/* ==========================================================================
   12. Footer
   ========================================================================== */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--surface-border);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-24);
}

.footer__container {
  max-width: var(--container-xl);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

@media (min-width: 640px) { .footer__grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1024px) { .footer__grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; } }

.footer__brand-name .navbar__mark {
  margin-right: var(--space-2);
}

.footer__brand-name {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-weight: var(--font-normal);
  font-size: var(--text-sm);
  letter-spacing: var(--tracking-wide);
  color: var(--text-primary);
  margin-bottom: var(--space-3);
}
.footer__brand-name svg { width: 24px; height: 24px; color: var(--accent-primary); }
.footer__brand p { color: var(--text-secondary); font-size: var(--text-sm); max-width: 260px; }

.footer__column h4 {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--text-tertiary);
  margin-bottom: var(--space-4);
}

.footer__column ul { list-style: none; display: grid; gap: var(--space-2); }
.footer__column a {
  color: var(--text-secondary);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}
.footer__column a:hover { color: var(--accent-hover); }

.footer__bottom {
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px solid var(--surface-border);
  text-align: center;
  color: var(--text-tertiary);
  font-size: var(--text-sm);
}

.footer__credit {
  margin-top: var(--space-2);
  color: var(--text-tertiary);
}
.footer__credit a {
  color: var(--text-secondary);
  font-weight: var(--font-medium);
  transition: color var(--transition-fast);
}
.footer__credit a:hover { color: var(--accent-hover); }

/* ==========================================================================
   13. Search modal
   ========================================================================== */
.search-modal {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.search-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.search-modal__content {
  position: relative;
  width: min(600px, calc(100% - var(--space-8)));
  margin-top: 15vh;
  background: var(--bg-elevated);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: modal-pop 0.2s ease-out;
}

.search-modal__input-wrapper {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--surface-border);
}
.search-modal__input-wrapper svg { width: 20px; height: 20px; color: var(--text-tertiary); flex-shrink: 0; }

.search-modal__input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-size: var(--text-lg);
  color: var(--text-primary);
}
.search-modal__input::placeholder { color: var(--text-tertiary); }

.search-modal__kbd,
kbd.search-modal__kbd {
  padding: 2px var(--space-2);
  border-radius: var(--radius-sm);
  border: 1px solid var(--surface-border);
  background: var(--bg-tertiary);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--text-tertiary);
}

.search-modal__results {
  max-height: 55vh;
  overflow-y: auto;
  padding: var(--space-2);
}

.search-result {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
}
.search-result:hover,
.search-result.is-active {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}
.search-result__title { font-weight: var(--font-medium); color: var(--text-primary); display: flex; align-items: center; gap: var(--space-2); }
.search-result__meta { font-size: var(--text-xs); color: var(--text-tertiary); margin-top: 2px; }
.search-result mark { background: var(--accent-muted); color: var(--accent-hover); padding: 0 2px; border-radius: 3px; }

.search-empty,
.search-hint {
  padding: var(--space-6);
  text-align: center;
  color: var(--text-tertiary);
  font-size: var(--text-sm);
}

/* ==========================================================================
   14. Roadmap node
   ========================================================================== */
.roadmap {
  position: relative;
  max-width: var(--container-lg);
  margin-inline: auto;
  padding: var(--space-8) 0;
}

/* central line */
.roadmap::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 20px;
  width: 2px;
  background: linear-gradient(to bottom, var(--surface-border), var(--accent-primary), var(--surface-border));
}

@media (min-width: 900px) {
  .roadmap::before { left: 50%; transform: translateX(-50%); }
}

.roadmap-node {
  position: relative;
  padding-left: 56px;
  margin-bottom: var(--space-8);
}

@media (min-width: 900px) {
  .roadmap-node { width: 50%; padding-left: 0; }
  .roadmap-node--left { left: 0; padding-right: 48px; text-align: right; }
  .roadmap-node--right { left: 50%; padding-left: 48px; }
}

.roadmap-node__dot {
  position: absolute;
  top: var(--space-5);
  left: 12px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 3px solid var(--node-color, var(--accent-primary));
  z-index: 1;
  transition: background var(--transition-base), box-shadow var(--transition-base);
}

@media (min-width: 900px) {
  .roadmap-node--left .roadmap-node__dot { left: auto; right: -9px; }
  .roadmap-node--right .roadmap-node__dot { left: -9px; }
}

.roadmap-node.is-complete .roadmap-node__dot {
  background: var(--node-color, var(--accent-primary));
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--node-color, var(--accent-primary)) 25%, transparent);
}

.roadmap-node__card {
  display: block;
  padding: var(--space-5);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  border-left: 3px solid var(--node-color, var(--accent-primary));
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-smooth);
}

@media (min-width: 900px) {
  .roadmap-node--left .roadmap-node__card { border-left: 1px solid var(--surface-border); border-right: 3px solid var(--node-color, var(--accent-primary)); }
}

.roadmap-node__card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  color: inherit;
}

.roadmap-node__number {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--node-color, var(--accent-primary));
  font-weight: var(--font-bold);
}

.roadmap-node__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin: var(--space-1) 0 var(--space-3);
}

.roadmap-node__check {
  display: none;
  color: var(--color-success);
  font-weight: var(--font-bold);
  margin-left: var(--space-2);
}
.roadmap-node.is-complete .roadmap-node__check { display: inline; }

/* roadmap legend */
.roadmap-legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: center;
  margin-bottom: var(--space-12);
}
.roadmap-legend__item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}
.roadmap-legend__swatch { width: 14px; height: 14px; border-radius: 50%; }

/* ==========================================================================
   15. Level card (szintek.html)
   ========================================================================== */
.levels-track {
  position: relative;
  display: grid;
  gap: var(--space-8);
  max-width: var(--container-md);
  margin-inline: auto;
}

.level-card {
  position: relative;
  border: 1px solid var(--surface-border);
  border-left: 4px solid var(--level-color, var(--accent-primary));
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  overflow: hidden;
}

.level-card__header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6);
  background: linear-gradient(135deg, color-mix(in srgb, var(--level-color, var(--accent-primary)) 18%, transparent), transparent);
}

.level-card__emoji { font-size: var(--text-2xl); }
.level-card__title { font-size: var(--text-2xl); font-weight: var(--font-bold); color: var(--text-primary); }
.level-card__body { padding: var(--space-6); }

.level-card__skills {
  list-style: none;
  display: grid;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.level-card__skills li {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  font-size: var(--text-sm);
}
.level-card__skills li::before {
  content: "▹";
  color: var(--level-color, var(--accent-primary));
  font-weight: var(--font-bold);
}

.level-card__chapters h4 {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--text-tertiary);
  margin-bottom: var(--space-3);
}
.level-card__chapters-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  list-style: none;
}
.level-card__chapters-list a {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--accent-muted);
  color: var(--accent-hover);
  font-size: var(--text-sm);
}
.level-card__chapters-list a:hover { background: var(--accent-primary); color: #fff; }

.level-card__question {
  margin-top: var(--space-5);
  font-style: italic;
  color: var(--text-secondary);
  font-size: var(--text-sm);
}

/* ==========================================================================
   17. Toast
   ========================================================================== */
.toast {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  border: 1px solid var(--surface-border);
  box-shadow: var(--shadow-lg);
  color: var(--text-primary);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.toast.is-visible { opacity: 1; transform: translateY(0); }
.toast__message::before { content: ""; }

/* ==========================================================================
   18. Code block
   ========================================================================== */
.code-block {
  margin-block: var(--space-6);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg-tertiary);
}

.code-block__header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-4);
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--surface-border);
}

.code-block__lang {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--accent-hover);
}

.code-block__caption {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}

/* Copy button (code.js injects it) — pushed to the right of the header */
.code-block__copy {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  border: 1px solid var(--surface-border);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}
.code-block__copy:hover { background: var(--bg-elevated); color: var(--text-primary); border-color: var(--surface-border-hover); }
.code-block__copy.is-copied { color: var(--color-success); border-color: var(--color-success); }
.code-block__copy svg { flex-shrink: 0; }

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

.code-block code {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  white-space: pre;
}

/* Syntax highlight tokens (code.js) — theme-adaptive */
.code-block code .tok-keyword { color: var(--accent-hover); font-weight: var(--font-medium); }
.code-block code .tok-string  { color: var(--color-success); }
.code-block code .tok-comment { color: var(--text-tertiary); font-style: italic; }
.code-block code .tok-number  { color: var(--color-warning); }
.code-block code .tok-func    { color: var(--color-info); }
[data-theme="light"] .code-block code .tok-string { color: #16794a; }
[data-theme="light"] .code-block code .tok-number { color: #9a5b00; }

/* ==========================================================================
   19. Data table
   ========================================================================== */
.table-wrapper {
  margin-block: var(--space-6);
  overflow-x: auto;
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

.data-table th,
.data-table td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--surface-border);
  vertical-align: top;
}

.data-table thead th {
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-weight: var(--font-semibold);
  white-space: nowrap;
}

.data-table tbody th {
  color: var(--text-primary);
  font-weight: var(--font-semibold);
  background: var(--bg-secondary);
}

.data-table td { color: var(--text-secondary); }
.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td { border-bottom: none; }
.data-table tbody tr:hover td,
.data-table tbody tr:hover th { background: var(--bg-tertiary); }

/* ==========================================================================
   5. TOC (desktop sticky)
   ========================================================================== */
.toc {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-8));
  max-height: calc(100vh - var(--nav-height) - var(--space-16));
  overflow-y: auto;
  padding: var(--space-4) var(--space-2);
  scrollbar-width: thin;
}

.toc__title {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--text-tertiary);
  margin-bottom: var(--space-3);
  padding-left: var(--space-3);
}

.toc__list,
.toc__sublist { list-style: none; }
.toc__sublist { padding-left: var(--space-3); }

.toc__link {
  display: block;
  padding: var(--space-1) var(--space-3);
  border-left: 2px solid transparent;
  color: var(--text-tertiary);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.toc__link:hover { color: var(--text-secondary); }

.toc__item--active > .toc__link {
  color: var(--text-primary);
  border-left-color: var(--accent-primary);
  font-weight: var(--font-medium);
}

/* ==========================================================================
   20. Collapsible TOC (mobile/tablet)
   ========================================================================== */
.toc--collapsible {
  position: static;
  max-height: none;
  overflow: visible;
  margin-block: var(--space-6);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  padding: 0;
}

.toc__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-weight: var(--font-medium);
  color: var(--text-primary);
  font-size: var(--text-sm);
}

.toc__toggle::after {
  content: "▾";
  transition: transform var(--transition-fast);
  color: var(--text-tertiary);
}
.toc__toggle[aria-expanded="true"]::after { transform: rotate(180deg); }

.toc__panel { padding: 0 var(--space-3) var(--space-3); }

/* ==========================================================================
   21. Breadcrumb
   ========================================================================== */
.breadcrumb { margin-bottom: var(--space-6); }

.breadcrumb__list,
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  list-style: none;
  font-size: var(--text-sm);
  color: var(--text-tertiary);
}

.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--accent-hover); }

.breadcrumb li:not(:last-child)::after {
  content: "→";
  margin-left: var(--space-2);
  color: var(--text-tertiary);
}

.breadcrumb [aria-current="page"] { color: var(--text-primary); }

/* separator when using inline spans */
.breadcrumb span[aria-hidden="true"] { color: var(--text-tertiary); }

/* ==========================================================================
   6. Chapter nav (prev/next)
   ========================================================================== */
.chapter-nav {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-top: var(--space-12);
}

@media (min-width: 640px) {
  .chapter-nav { grid-template-columns: 1fr 1fr; }
}

.chapter-nav__link {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-5);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  transition: transform var(--transition-smooth), border-color var(--transition-smooth), box-shadow var(--transition-smooth);
}

.chapter-nav__link:hover {
  transform: translateY(-3px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
  color: inherit;
}

.chapter-nav__link--next { text-align: right; }

.chapter-nav__direction {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
}

.chapter-nav__title {
  font-weight: var(--font-semibold);
  color: var(--text-primary);
}

/* ==========================================================================
   22. Related chapters
   ========================================================================== */
.related-chapters {
  margin-top: var(--space-12);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  border: 1px solid var(--surface-border);
}

.related-chapters h2 {
  border-top: none !important;
  padding-top: 0 !important;
  margin-top: 0 !important;
  font-size: var(--text-xl);
  margin-bottom: var(--space-4);
}

.related-chapters__list { list-style: none; display: grid; gap: var(--space-3); }
.related-chapters__list li {
  padding-left: var(--space-4);
  border-left: 2px solid var(--surface-border);
  color: var(--text-secondary);
  font-size: var(--text-sm);
}
.related-chapters__list a { font-weight: var(--font-medium); }

/* ==========================================================================
   Content figure (images)
   ========================================================================== */
.content-figure {
  margin-block: var(--space-6);
}
.content-figure img {
  width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--surface-border);
}
.content-figure figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  text-align: center;
}

/* ==========================================================================
   Page hero (interior pages: roadmap, szintek, projektek, 404)
   ========================================================================== */
.page-hero {
  text-align: left;
  padding: calc(var(--nav-height) + var(--space-12)) var(--space-5) var(--space-12);
  max-width: var(--container-xl);
  margin-inline: auto;
  border-bottom: 1px solid var(--surface-border);
}
.page-hero__title {
  font-family: var(--font-serif);
  font-size: var(--text-4xl);
  font-weight: 600;
  letter-spacing: var(--tracking-tight);
  margin-bottom: var(--space-4);
  line-height: var(--leading-tight);
  max-width: 18ch;
  text-wrap: balance;
}
.page-hero__subtitle {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  max-width: 48ch;
  margin-inline: 0;
  line-height: var(--leading-relaxed);
}

/* ==========================================================================
   Project card (projektek.html)
   ========================================================================== */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  max-width: var(--container-lg);
  margin-inline: auto;
}

.project-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  padding: var(--space-6);
  border: 1px solid var(--surface-border);
  border-left: 3px solid var(--project-color, var(--accent-primary));
  border-radius: 0;
  background: var(--bg-secondary);
  transition: box-shadow var(--transition-base), border-color var(--transition-base);
  scroll-margin-top: calc(var(--nav-height) + var(--space-6));
  /* Prevent grid/flex blowout: allow the card to shrink below its content's
     min-content width so long inline <code> tokens can't force overflow. */
  min-width: 0;
  overflow-wrap: break-word;
}
.project-card:hover { box-shadow: var(--shadow-md); }

/* Long inline code tokens (e.g. commands) must wrap on narrow screens */
.project-card code {
  overflow-wrap: anywhere;
  word-break: break-word;
}

@media (min-width: 768px) {
  .project-card { padding: var(--space-8); }
}

.project-card__header {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--surface-border);
}
.project-card__number {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--project-color, var(--accent-primary));
}
.project-card__title { font-size: var(--text-2xl); font-weight: var(--font-bold); color: var(--text-primary); flex: 1; min-width: 200px; letter-spacing: var(--tracking-tight); }
.project-card__time { font-size: var(--text-sm); color: var(--text-tertiary); display: inline-flex; align-items: center; gap: var(--space-1); }

/* Lead / scenario brief */
.project-card__brief {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}
.project-card__brief strong { color: var(--text-primary); }

.project-card__desc { color: var(--text-secondary); line-height: var(--leading-relaxed); }
.project-card__desc + .project-card__desc { margin-top: var(--space-3); }

/* Sub-section within an assignment */
.project-card__section {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.project-card__section-title {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--project-color, var(--accent-primary));
}
.project-card__section-title svg { width: 16px; height: 16px; }

/* Goals / "amit megtanulsz" pill list */
.project-card__goals {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.project-card__goals li {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  border: 1px solid var(--surface-border);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* Task list (numbered milestones) */
.project-card__tasks {
  list-style: none;
  counter-reset: task;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.project-card__tasks > li {
  counter-increment: task;
  position: relative;
  padding-left: calc(var(--space-8) + var(--space-1));
  color: var(--text-secondary);
  line-height: var(--leading-normal);
}
.project-card__tasks > li::before {
  content: counter(task);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: var(--accent-muted);
  color: var(--project-color, var(--accent-hover));
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
}
.project-card__tasks > li strong { color: var(--text-primary); }

/* Acceptance criteria checklist */
.project-card__acceptance {
  padding: var(--space-5);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-success) 6%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-success) 20%, transparent);
}
.project-card__acceptance .project-card__section-title { color: var(--color-success); }
.project-card__acceptance ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-top: var(--space-3);
}
.project-card__acceptance li {
  position: relative;
  padding-left: var(--space-6);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
  font-size: var(--text-sm);
}
.project-card__acceptance li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--color-success);
  font-weight: var(--font-bold);
}

/* Stretch goals (optional extras) */
.project-card__stretch ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-top: var(--space-3);
}
.project-card__stretch li {
  position: relative;
  padding-left: var(--space-6);
  color: var(--text-tertiary);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
}
.project-card__stretch li::before {
  content: "★";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--color-warning);
}

/* Footer: chapters + prereq */
.project-card__footer {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding-top: var(--space-5);
  border-top: 1px solid var(--surface-border);
}
.project-card__chapters h3 {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--text-tertiary);
  margin-bottom: var(--space-2);
}
.project-card__chapters ul { list-style: none; display: flex; flex-wrap: wrap; gap: var(--space-2); }
.project-card__chapters a {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--accent-muted);
  color: var(--accent-hover);
  font-size: var(--text-sm);
}
.project-card__chapters a:hover { background: var(--accent-primary); color: #fff; }

.project-card__prereq {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
}
.project-card__prereq strong { color: var(--text-secondary); }

/* ==========================================================================
   Intro / prose block (landing intro)
   ========================================================================== */
.prose { max-width: var(--container-content); margin-inline: auto; }
.prose p { color: var(--text-secondary); line-height: var(--leading-relaxed); margin-bottom: var(--space-4); }

/* ==========================================================================
   404 page
   ========================================================================== */
.error-page {
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: var(--space-4);
  padding: var(--space-8);
}
.error-page__code {
  font-size: clamp(4rem, 20vw, 9rem);
  font-weight: var(--font-bold);
  line-height: 1;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* ==========================================================================
   23. Glossary (fogalomtár) — /fogalomtar.html
   ========================================================================== */
.glossary-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  margin-bottom: var(--space-8);
  max-width: var(--container-md);
  margin-inline: auto;
}

.glossary-search {
  flex: 1;
  min-width: 220px;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  transition: border-color var(--transition-fast);
}
.glossary-search:focus-within { border-color: var(--accent-primary); }
.glossary-search svg { width: 18px; height: 18px; color: var(--text-tertiary); flex-shrink: 0; }
.glossary-search input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: var(--text-base);
}
.glossary-search input::placeholder { color: var(--text-tertiary); }

.glossary-count {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  white-space: nowrap;
}

/* A-Z jump index */
.glossary-alpha {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  justify-content: center;
  margin-bottom: var(--space-8);
}
.glossary-alpha a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border: 1px solid var(--surface-border);
}
.glossary-alpha a:hover { background: var(--accent-muted); color: var(--accent-hover); }
.glossary-alpha a.is-empty { opacity: 0.3; pointer-events: none; }

.glossary-list {
  max-width: var(--container-md);
  margin-inline: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.glossary-group__letter {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--accent-primary);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--surface-border);
  margin-top: var(--space-6);
  scroll-margin-top: calc(var(--nav-height) + var(--space-4));
}

.glossary-item {
  padding: var(--space-4) var(--space-5);
  border: 1px solid var(--surface-border);
  border-left: 3px solid var(--accent-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--bg-secondary);
}
.glossary-item__term {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}
.glossary-item__def { color: var(--text-secondary); line-height: var(--leading-normal); margin-bottom: var(--space-2); }
.glossary-item__def mark { background: var(--accent-muted); color: var(--accent-hover); padding: 0 2px; border-radius: 3px; }
.glossary-item__source {
  font-size: var(--text-sm);
}
.glossary-item__source a {
  color: var(--text-tertiary);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}
.glossary-item__source a:hover { color: var(--accent-hover); }

.glossary-empty {
  text-align: center;
  padding: var(--space-16) var(--space-4);
  color: var(--text-tertiary);
}

/* ==========================================================================
   24. Chapter diagram (inline SVG figure)
   ========================================================================== */
.diagram {
  margin-block: var(--space-8);
  padding: var(--space-5);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
}
.diagram svg { width: 100%; height: auto; display: block; }
.diagram figcaption {
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  text-align: center;
}
/* diagram theming tokens (SVG uses currentColor + these vars) */
.diagram {
  --dia-stroke: var(--surface-border-hover);
  --dia-text: var(--text-secondary);
  --dia-label: var(--text-primary);
  --dia-accent: var(--chapter-color, var(--accent-primary));
  --dia-node-bg: var(--bg-tertiary);
}
.diagram text { fill: var(--dia-text); font-family: var(--font-sans); }
.diagram .dia-label { fill: var(--dia-label); font-weight: 600; }
.diagram .dia-node { fill: var(--dia-node-bg); stroke: var(--dia-stroke); }
.diagram .dia-node--accent { fill: color-mix(in srgb, var(--dia-accent) 15%, transparent); stroke: var(--dia-accent); }
.diagram .dia-edge { stroke: var(--dia-stroke); fill: none; }
.diagram .dia-edge--accent { stroke: var(--dia-accent); fill: none; }
.diagram .dia-arrow { fill: var(--dia-stroke); }
.diagram .dia-arrow--accent { fill: var(--dia-accent); }

/* ==========================================================================
   25. Quiz (fejezetvégi önellenőrzés)
   ========================================================================== */
.quiz {
  margin-top: var(--space-12);
  padding: var(--space-6);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
}
.quiz__header { margin-bottom: var(--space-5); }
.quiz__title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--text-primary);
  border: none !important;
  padding: 0 !important;
  margin: 0 0 var(--space-1) !important;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.quiz__subtitle { font-size: var(--text-sm); color: var(--text-tertiary); }

.quiz__question { margin-bottom: var(--space-6); }
.quiz__question:last-of-type { margin-bottom: var(--space-4); }
.quiz__q-text {
  font-weight: var(--font-medium);
  color: var(--text-primary);
  margin-bottom: var(--space-3);
  line-height: var(--leading-normal);
}
.quiz__q-num { color: var(--accent-primary); font-family: var(--font-mono); font-weight: var(--font-bold); margin-right: var(--space-2); }

.quiz__options { display: flex; flex-direction: column; gap: var(--space-2); list-style: none; }
.quiz__option {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  text-align: left;
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  cursor: pointer;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}
.quiz__option:hover:not([disabled]) { border-color: var(--surface-border-hover); background: var(--bg-elevated); }
.quiz__option[disabled] { cursor: default; }
.quiz__option-marker {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  border: 1px solid var(--surface-border-hover);
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
  font-family: var(--font-mono);
  color: var(--text-tertiary);
}
.quiz__option.is-correct {
  border-color: var(--color-success);
  background: color-mix(in srgb, var(--color-success) 10%, transparent);
  color: var(--text-primary);
}
.quiz__option.is-correct .quiz__option-marker { background: var(--color-success); color: #05240f; border-color: var(--color-success); }
.quiz__option.is-wrong {
  border-color: var(--color-error);
  background: color-mix(in srgb, var(--color-error) 10%, transparent);
  color: var(--text-primary);
}
.quiz__option.is-wrong .quiz__option-marker { background: var(--color-error); color: #2a0808; border-color: var(--color-error); }

.quiz__explanation {
  margin-top: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  background: var(--accent-muted);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
}
.quiz__explanation strong { color: var(--text-primary); }

.quiz__result {
  margin-top: var(--space-5);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  border: 1px solid var(--surface-border);
  text-align: center;
}
.quiz__result-score { font-size: var(--text-2xl); font-weight: var(--font-bold); color: var(--text-primary); }
.quiz__result-label { font-size: var(--text-sm); color: var(--text-secondary); margin-top: var(--space-1); }
.quiz__next-wrap {
  margin-top: var(--space-4);
}
.quiz__next {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  background: var(--accent-gradient);
  color: #fff;
  font-weight: var(--font-medium);
  font-size: var(--text-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.quiz__next:hover { transform: translateY(-1px); box-shadow: var(--shadow-md), var(--shadow-glow); color: #fff; }
.quiz__next--review {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--surface-border-hover);
}
.quiz__next--review:hover { color: var(--text-primary); background: var(--bg-tertiary); }

.quiz__reset {
  display: block;
  margin: var(--space-4) auto 0;
  font-size: var(--text-sm);
  color: var(--accent-hover);
  background: none;
  text-decoration: underline;
  cursor: pointer;
}

/* ==========================================================================
   26. Print stylesheet — clean, readable PDF/print output
   ========================================================================== */
@media print {
  /* Hide interactive chrome */
  .navbar,
  .mobile-menu,
  .sidebar,
  .toc,
  #toc-mobile-mount,
  .chapter-preview,
  .progress-bar,
  .search-modal,
  .toast,
  .quiz,
  .chapter-nav,
  .footer,
  .skip-nav,
  .code-block__copy,
  .hero__bg {
    display: none !important;
  }

  /* Reset the chapter grid to a single flowing column */
  .chapter-layout {
    display: block !important;
    max-width: 100% !important;
  }
  .chapter-main,
  .chapter-content {
    max-width: 100% !important;
    padding: 0 !important;
  }

  /* Light-on-white for ink economy, regardless of theme */
  :root,
  [data-theme="light"],
  [data-theme="dark"] {
    --bg-primary: #fff;
    --bg-secondary: #fff;
    --bg-tertiary: #f4f4f5;
    --bg-elevated: #fff;
    --text-primary: #000;
    --text-secondary: #1a1a1a;
    --text-tertiary: #555;
    --surface-border: #ccc;
  }
  html, body {
    background: #fff !important;
    color: #000 !important;
    font-size: 11pt;
  }

  main, .container { max-width: 100% !important; }

  /* Avoid awkward breaks */
  h1, h2, h3 { break-after: avoid; }
  .callout, .code-block, .diagram, .data-table, figure, pre { break-inside: avoid; }
  section { break-inside: auto; }

  /* Show link URLs for reference (only external + internal chapter links) */
  .chapter-content a[href^="/"]::after,
  .chapter-content a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 9pt;
    color: #555;
    word-break: break-all;
  }

  /* Keep diagrams legible on paper */
  .diagram { border: 1px solid #ccc; }
  .diagram .dia-node { fill: #f4f4f5; stroke: #999; }
  .diagram text, .diagram .dia-label { fill: #000; }
}