/* ══════════════════════════════════════════════════
   The Neon Scholar — Vibecoding Glossary Theme
   Converted from Tailwind reference to vanilla CSS
   ══════════════════════════════════════════════════ */

/* ── Reset & Variables ── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Surface & Background */
  --color-bg: #040a2f;
  --color-surface: #121b4c;
  --color-surface-hover: #1d2760;
  --color-surface-dim: #070f38;
  --color-surface-high: #172056;
  --color-surface-lowest: #000000;

  /* Text */
  --color-text: #e2e3ff;
  --color-text-muted: #a3a8d5;

  /* Accent: Secondary (Purple) */
  --color-primary: #af88ff;
  --color-primary-dim: #8a4cfc;
  --color-primary-deep: #6001d1;
  --color-on-primary: #2b0065;

  /* Accent: Tertiary (Neon Cyan) */
  --color-tertiary: #a1ffef;
  --color-tertiary-dim: #5ae4d0;

  /* Border */
  --color-border: #3f456c;
  --color-outline: #6d739d;

  /* Category Colors */
  --color-ai: #af88ff;
  --color-prompt: #dae2fd;
  --color-tools: #a1ffef;
  --color-practice: #fbbf24;

  /* Level Colors */
  --color-level-beginner: #5de7d3;
  --color-level-basic: #af88ff;
  --color-level-advanced: #ff716c;

  /* Typography */
  --font-headline: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-label: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.25rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --font-size-4xl: 3.5rem;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 52px;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
}

::selection {
  background: var(--color-tertiary);
  color: #005b51;
}

/* ── Hero Section ── */
.hero {
  position: relative;
  text-align: center;
  padding: var(--space-3xl) var(--space-lg) var(--space-2xl);
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -20%;
  left: -10%;
  width: 60%;
  height: 80%;
  border-radius: 50%;
  background: rgba(93, 231, 211, 0.05);
  filter: blur(120px);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -10%;
  right: -5%;
  width: 50%;
  height: 70%;
  border-radius: 50%;
  background: rgba(175, 136, 255, 0.05);
  filter: blur(120px);
  pointer-events: none;
}

.hero__container {
  max-width: 720px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero__title {
  font-family: var(--font-headline);
  font-size: var(--font-size-4xl);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 0.95;
  margin-bottom: var(--space-lg);
  color: var(--color-tertiary);
  text-shadow: 0 0 40px rgba(161, 255, 239, 0.3);
}

.hero__subtitle {
  font-family: var(--font-headline);
  font-size: var(--font-size-xl);
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: var(--space-xl);
  letter-spacing: -0.02em;
}

.hero__description {
  font-size: var(--font-size-base);
  color: var(--color-text-muted);
  line-height: 1.9;
  max-width: 560px;
  margin: 0 auto;
}

/* ── Hero Stats ── */
.hero__stats {
  display: flex;
  justify-content: center;
  gap: var(--space-2xl);
  margin-top: var(--space-xl);
}

.hero__stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero__stat-num {
  font-family: var(--font-headline);
  font-size: var(--font-size-2xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
}

.hero__stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-outline);
  margin-top: var(--space-xs);
}

/* ── Jump Menu ── */
.jump-menu {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(4, 10, 47, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(63, 69, 108, 0.3);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.jump-menu::-webkit-scrollbar { display: none; }

.jump-menu__link {
  padding: 0.375rem 0.875rem;
  font-family: var(--font-label);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-outline);
  text-decoration: none;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.jump-menu__link:hover {
  color: var(--color-text);
}

.jump-menu__link--active {
  color: var(--color-tertiary);
  background: rgba(90, 228, 208, 0.1);
}

/* ── Floating Action Buttons ── */
.fab {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.fab__btn {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.fab__btn:hover {
  transform: translateY(-2px);
}

.fab__btn--home {
  color: #fff;
  background: rgba(109, 115, 157, 0.7);
  backdrop-filter: blur(8px);
}

.fab__btn--home:hover {
  background: rgba(109, 115, 157, 0.9);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

.fab__btn--dark {
  color: #fff;
  background: rgba(109, 115, 157, 0.7);
  backdrop-filter: blur(8px);
}

.fab__btn--dark:hover {
  background: rgba(109, 115, 157, 0.9);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

.fab__btn--top {
  color: #fff;
  background: #2563eb;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.fab__btn--top:hover {
  background: #1d4ed8;
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

/* ── Light Mode (glossary) ── */

html.light .hero { background: var(--color-bg); }
html.light .hero::before, html.light .hero::after { opacity: 0; }
html.light .hero__title { color: var(--color-text); text-shadow: none; }
html.light .hero__subtitle { color: var(--color-primary); }
html.light .hero__description { color: var(--color-text-muted); }

html.light .hero__stat-num { color: var(--color-primary); }
html.light .hero__stat-label { color: var(--color-outline); }

html.light .search__input { background: #fff; border-color: #d4d8e3; color: #1a1d2e; }
html.light .search__input:focus { border-color: #7c4dff; box-shadow: 0 0 0 3px rgba(124,77,255,0.1); }
html.light .search__input::placeholder { color: #9ca3af; }
html.light .search__icon { color: #9ca3af; }
html.light .search__clear { color: #9ca3af; }
html.light .search__clear:hover { color: #1a1d2e; background: rgba(0,0,0,0.05); }

html.light .tabs__btn { background: #fff; border-color: #d4d8e3; color: #4a5068; }
html.light .tabs__btn:hover { color: #1a1d2e; border-color: #9ca3af; background: #f5f6fa; }
html.light .tabs__btn--active { color: #fff; border-color: transparent; background: linear-gradient(135deg, #7c4dff, #6234cc); box-shadow: 0 0 16px rgba(124,77,255,0.2); }
html.light .tabs__count { color: #8890a8; background: rgba(0,0,0,0.05); }
html.light .tabs__btn--active .tabs__count { color: rgba(255,255,255,0.8); background: rgba(255,255,255,0.2); }

html.light .filters__btn { border-color: #d4d8e3; color: #4a5068; }
html.light .filters__btn:hover { color: #1a1d2e; border-color: #9ca3af; }
html.light .filters__btn--active { color: #1a1d2e; border-color: #1a1d2e; background: rgba(0,0,0,0.03); }

html.light .counter { color: #8890a8; }

html.light .card { background: #fff; border-color: #d4d8e3; backdrop-filter: none; }
html.light .card:hover { box-shadow: 0 4px 20px rgba(0,0,0,0.06); border-color: #9ca3af; }
html.light .card__term { color: #1a1d2e; }
html.light .card__term-ko { color: #8890a8; }
html.light .card__short-def { color: #4a5068; }
html.light .card__category-icon { opacity: 0.8; }
html.light .card__toggle { color: #9ca3af; }
html.light .card:hover .card__toggle { color: #7c4dff; }
html.light .card--expanded .card__toggle { color: #0d9488; }
html.light .card__detail-inner { border-color: #e5e7eb; }
html.light .card__section-title { color: #0d9488; }
html.light .card__section-text { color: #4a5068; }
html.light .card--expanded { border-left-color: #7c4dff; }
html.light .card--expanded[data-category="ai-basic"] { border-left-color: #7c4dff; box-shadow: 0 0 20px rgba(124,77,255,0.05); }
html.light .card--expanded[data-category="prompt"] { border-left-color: #4a5068; box-shadow: 0 0 20px rgba(0,0,0,0.03); }
html.light .card--expanded[data-category="tools"] { border-left-color: #0d9488; box-shadow: 0 0 20px rgba(13,148,136,0.05); }
html.light .card--expanded[data-category="practice"] { border-left-color: #d97706; box-shadow: 0 0 20px rgba(217,119,6,0.05); }

html.light .card__badge--beginner { background: linear-gradient(135deg, #059669, #047857); color: #fff; }
html.light .card__badge--basic { background: linear-gradient(135deg, #7c4dff, #6234cc); color: #fff; }
html.light .card__badge--advanced { background: linear-gradient(135deg, #dc2626, #b91c1c); color: #fff; }

html.light .related__pill { color: #0d9488; background: rgba(13,148,136,0.06); border-color: rgba(13,148,136,0.2); }
html.light .related__pill:hover { color: #0f766e; background: rgba(13,148,136,0.12); border-color: rgba(13,148,136,0.4); }
html.light .card__section--related { border-color: #e5e7eb; }

html.light .jump-menu { background: rgba(245,246,250,0.97); border-color: #d4d8e3; }
html.light .jump-menu__link { color: #8890a8; }
html.light .jump-menu__link:hover { color: #1a1d2e; }
html.light .jump-menu__link--active { color: #0d9488; background: rgba(13,148,136,0.08); }

html.light .guide__heading { color: #1a1d2e; }
html.light .guide__intro { color: #4a5068; }
html.light .guide { border-color: #e5e7eb; }

html.light .roadmap__item,
html.light .pc__item,
html.light .pitfall__item,
html.light .cs__item,
html.light .ed__item { background: #fff; border-color: #d4d8e3; }

html.light .roadmap__item:hover,
html.light .pc__item:hover,
html.light .pitfall__item:hover,
html.light .cs__item:hover,
html.light .ed__item:hover { border-color: #9ca3af; }

html.light .roadmap__day { color: #fff; }
html.light .roadmap__title { color: #1a1d2e; }
html.light .roadmap__desc { color: #4a5068; }
html.light .roadmap__action { color: #0d9488; background: rgba(13,148,136,0.05); }
html.light .roadmap__result { color: #7c4dff; background: rgba(124,77,255,0.05); }

html.light .pc__goal { color: #1a1d2e; }
html.light .pc__label { color: #1a1d2e; }
html.light .pc__code { color: #4a5068; }
html.light .pc__why { color: #0d9488; }
html.light .pc__tags { color: #8890a8; }
html.light .pc__tag { color: #7c4dff; background: rgba(124,77,255,0.06); border-color: rgba(124,77,255,0.2); }
html.light .pc__box--bad { background: rgba(220,38,38,0.04); border-color: rgba(220,38,38,0.15); }
html.light .pc__box--good { background: rgba(5,150,105,0.04); border-color: rgba(5,150,105,0.15); }

html.light .compare-table th { background: #f5f6fa; color: #4a5068; border-color: #d4d8e3; }
html.light .compare-table td { color: #4a5068; border-color: #e5e7eb; }
html.light .compare-table tr:hover td { background: #f9fafb; }
html.light .ct__tool { color: #1a1d2e !important; }
html.light .table-wrap { border-color: #d4d8e3; }

html.light .pitfall__title { color: #1a1d2e; }
html.light .pitfall__problem { color: #dc2626; }
html.light .pitfall__problem strong { color: #b91c1c; }
html.light .pitfall__solution { color: #0d9488; }
html.light .pitfall__solution strong { color: #0f766e; }

html.light .cs__when { color: #8890a8; }
html.light .cs__technique { color: #1a1d2e; }
html.light .cs__example { color: #0d9488; }
html.light .cs__tip { color: #4a5068; }

html.light .ed__code { color: #dc2626; background: rgba(220,38,38,0.05); }
html.light .ed__header .card__badge { color: #fff; }
html.light .ed__meaning { color: #4a5068; }
html.light .ed__meaning strong { color: #1a1d2e; }
html.light .ed__solution { color: #0d9488; }
html.light .ed__solution strong { color: #0f766e; }

html.light .empty__text { color: #1a1d2e; }
html.light .empty__hint { color: #8890a8; }

html.light .hero__subtitle { color: #7c4dff; }
html.light .hero__stat-num { color: #7c4dff; }
html.light .hero__stat-label { color: #8890a8; }

html.light ::selection { background: #7c4dff; color: #fff; }

/* ── Tab Count Badge ── */
.tabs__count {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--color-outline);
  background: rgba(226, 227, 255, 0.08);
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-full);
  margin-left: 0.25rem;
}

.tabs__btn--active .tabs__count {
  color: var(--color-on-primary);
  background: rgba(255, 255, 255, 0.2);
}

/* ── Main Content ── */
.main {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-lg);
}

/* ── Search Bar ── */
.search {
  margin-bottom: var(--space-xl);
}

.search__wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search__icon {
  position: absolute;
  left: var(--space-lg);
  color: var(--color-outline);
  pointer-events: none;
  transition: color var(--transition-fast);
}

.search__input {
  flex: 1;
  min-width: 0;
  padding: 1rem 2.5rem 1rem 3.25rem;
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background: rgba(23, 32, 86, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search__input::placeholder {
  color: var(--color-outline);
}

.search__input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(175, 136, 255, 0.15), 0 0 20px rgba(175, 136, 255, 0.1);
}

.search__input:focus ~ .search__icon,
.search__wrapper:focus-within .search__icon {
  color: var(--color-primary);
}

/* ── Category Tabs ── */
.tabs {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
  padding-bottom: var(--space-xs);
}

.tabs__btn {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 0.625rem 1.25rem;
  font-family: var(--font-headline);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  background: rgba(23, 32, 86, 0.4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  white-space: nowrap;
  letter-spacing: -0.01em;
  transition: all var(--transition-fast);
}

.tabs__btn:hover {
  color: var(--color-text);
  background: var(--color-surface-hover);
  border-color: var(--color-outline);
}

.tabs__btn--active {
  color: var(--color-on-primary);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dim));
  border-color: transparent;
  box-shadow: 0 0 20px rgba(175, 136, 255, 0.25);
}

.tabs__btn--active:hover {
  color: var(--color-on-primary);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dim));
}

.tabs__icon {
  font-size: var(--font-size-sm);
}

/* ── Level Filters ── */
.filters {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.filters__btn {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  font-family: var(--font-label);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filters__btn:hover {
  color: var(--color-text);
  border-color: var(--color-outline);
}

.filters__btn--active {
  color: var(--color-text);
  border-color: var(--color-text);
  background: rgba(226, 227, 255, 0.08);
}

.filters__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 6px currentColor;
}

.filters__dot--beginner {
  background: var(--color-level-beginner);
  box-shadow: 0 0 6px rgba(93, 231, 211, 0.5);
}
.filters__dot--basic {
  background: var(--color-level-basic);
  box-shadow: 0 0 6px rgba(175, 136, 255, 0.5);
}
.filters__dot--advanced {
  background: var(--color-level-advanced);
  box-shadow: 0 0 6px rgba(255, 113, 108, 0.5);
}

/* ── Result Counter ── */
.counter {
  font-family: var(--font-label);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-outline);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

/* ── Card List ── */
.cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* ── Term Card (Glass Card) ── */
.card {
  background: rgba(23, 32, 86, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(63, 69, 108, 0.6);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal), transform var(--transition-fast);
}

.card:hover {
  border-color: var(--color-outline);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  transform: translateY(-1px);
}

.card__header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-lg) var(--space-xl);
  cursor: pointer;
  user-select: none;
}

.card__header:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
  border-radius: var(--radius-xl);
}

.card__badge {
  flex-shrink: 0;
  padding: 0.2rem 0.625rem;
  font-family: var(--font-label);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border-radius: var(--radius-sm);
  color: #fff;
}

.card__badge--beginner {
  background: linear-gradient(135deg, #5de7d3, #00b89c);
  color: #003d35;
  box-shadow: 0 0 10px rgba(93, 231, 211, 0.25);
}
.card__badge--basic {
  background: linear-gradient(135deg, #af88ff, #8a4cfc);
  color: #1a0040;
  box-shadow: 0 0 10px rgba(175, 136, 255, 0.25);
}
.card__badge--advanced {
  background: linear-gradient(135deg, #ff716c, #d7383b);
  color: #2d0000;
  box-shadow: 0 0 10px rgba(255, 113, 108, 0.25);
}

.card__info {
  flex: 1;
  min-width: 0;
}

.card__term {
  font-family: var(--font-headline);
  font-size: var(--font-size-lg);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.2rem;
  color: var(--color-text);
}

.card__term-ko {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-outline);
  margin-left: var(--space-sm);
  font-weight: 400;
}

.card__short-def {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

.card__category-icon {
  flex-shrink: 0;
  font-size: var(--font-size-lg);
  opacity: 0.6;
  transition: opacity var(--transition-fast);
}

.card:hover .card__category-icon {
  opacity: 1;
}

.card__bookmark {
  flex-shrink: 0;
  background: none;
  border: none;
  font-size: var(--font-size-base);
  color: var(--color-border);
  cursor: pointer;
  padding: 0 0.25rem;
  transition: color var(--transition-fast), transform var(--transition-fast);
  opacity: 0.4;
}
.card__bookmark:hover { opacity: 0.8; transform: scale(1.2); }
.card__bookmark--active { color: #fbbf24; opacity: 1; }
.card__bookmark--active:hover { opacity: 1; }
html.light .card__bookmark { color: #d4d8e3; }
html.light .card__bookmark--active { color: #f59e0b; opacity: 1; }

.card__toggle {
  flex-shrink: 0;
  font-size: var(--font-size-sm);
  color: var(--color-outline);
  transition: transform var(--transition-normal), color var(--transition-fast);
}

.card:hover .card__toggle {
  color: var(--color-primary);
}

.card--expanded .card__toggle {
  transform: rotate(180deg);
  color: var(--color-tertiary);
}

/* ── Accordion Detail ── */
.card__detail {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal);
}

.card--expanded .card__detail {
  max-height: 1000px;
}

.card__detail-inner {
  padding: 0 var(--space-xl) var(--space-xl);
  border-top: 1px solid rgba(63, 69, 108, 0.5);
  padding-top: var(--space-xl);
}

.card__section {
  margin-bottom: var(--space-lg);
}

.card__section:last-child {
  margin-bottom: 0;
}

.card__section-title {
  font-family: var(--font-headline);
  font-size: var(--font-size-sm);
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--color-tertiary-dim);
  letter-spacing: -0.01em;
}

.card__section-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: 1.9;
}

/* Category accent border on expanded card */
.card--expanded {
  border-left: 3px solid var(--color-primary);
}

.card--expanded[data-category="ai-basic"] {
  border-left-color: var(--color-ai);
  box-shadow: 0 0 30px rgba(175, 136, 255, 0.08);
}

.card--expanded[data-category="prompt"] {
  border-left-color: var(--color-prompt);
  box-shadow: 0 0 30px rgba(218, 226, 253, 0.06);
}

.card--expanded[data-category="tools"] {
  border-left-color: var(--color-tools);
  box-shadow: 0 0 30px rgba(161, 255, 239, 0.08);
}

.card--expanded[data-category="practice"] {
  border-left-color: var(--color-practice);
  box-shadow: 0 0 30px rgba(251, 191, 36, 0.08);
}

/* ── Empty State ── */
.empty {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
}

.empty__text {
  font-family: var(--font-headline);
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.empty__hint {
  font-size: var(--font-size-sm);
  color: var(--color-outline);
}

/* ── Footer ── */
.footer {
  text-align: center;
  padding: var(--space-xl) var(--space-lg);
  border-top: 1px solid rgba(63, 69, 108, 0.25);
  margin-top: var(--space-3xl);
  background: rgba(2, 6, 24, 0.5);
}

.footer__line {
  font-family: var(--font-label);
  font-size: 0.8rem;
  color: rgba(109, 115, 157, 0.6);
  letter-spacing: 0.01em;
}

.footer__sep {
  margin: 0 0.5rem;
  opacity: 0.4;
}

.footer__link {
  color: rgba(109, 115, 157, 0.6);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-tertiary-dim);
}

@media (max-width: 480px) {
  .footer__line {
    font-size: 0.7rem;
  }

  .footer__sep {
    display: none;
  }

  .footer__line {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
  }
}

/* ── Responsive: Mobile ── */
@media (max-width: 768px) {
  .hero {
    padding: var(--space-2xl) var(--space-md) var(--space-xl);
  }

  .hero__title {
    font-size: var(--font-size-2xl);
  }

  .hero__subtitle {
    font-size: var(--font-size-lg);
  }

  .main {
    padding: var(--space-lg) var(--space-md);
  }

  .card__header {
    padding: var(--space-md) var(--space-lg);
  }

  .card__term {
    font-size: var(--font-size-base);
  }

  .card__term-ko {
    display: block;
    margin-left: 0;
    margin-top: 0.125rem;
  }

  .card__detail-inner {
    padding: 0 var(--space-lg) var(--space-lg);
    padding-top: var(--space-md);
  }

  .tabs__btn {
    padding: 0.5rem 1rem;
  }

  .hero__stats {
    gap: var(--space-lg);
  }

  .hero__stat-num {
    font-size: var(--font-size-xl);
  }

  .jump-menu {
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
  }

  .jump-menu__link {
    font-size: 0.65rem;
    padding: 0.25rem 0.5rem;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: var(--font-size-xl);
  }

  .hero__subtitle {
    font-size: var(--font-size-base);
  }

  .card__header {
    padding: var(--space-md);
    gap: var(--space-sm);
  }

  .card__detail-inner {
    padding: 0 var(--space-md) var(--space-md);
    padding-top: var(--space-md);
  }
}

/* ── Password Gate ── */
.gate {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding-bottom: 6vh;
  background: radial-gradient(ellipse at 50% 30%, rgba(18, 27, 76, 0.8) 0%, var(--color-bg) 70%);
}

.gate__box {
  text-align: center;
  padding: var(--space-2xl);
  max-width: 460px;
  width: 100%;
}

.gate__logo {
  margin-bottom: var(--space-md);
  opacity: 0.8;
}

.gate__brand {
  font-family: var(--font-headline);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.3em;
  color: var(--color-text-muted);
  text-transform: uppercase;
  margin-bottom: var(--space-3xl);
}

.gate__caption {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-label);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  color: var(--color-outline);
  text-transform: uppercase;
  margin-bottom: var(--space-xl);
}

.gate__caption::before {
  content: '';
  display: inline-block;
  width: 12px;
  height: 12px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236d739d' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Crect x='3' y='11' width='18' height='11' rx='2' ry='2'/%3E%3Cpath d='M7 11V7a5 5 0 0 1 10 0v4'/%3E%3C/svg%3E");
  background-size: contain;
}

.gate__title {
  font-family: var(--font-headline);
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.4;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.gate__accent {
  color: var(--color-tertiary);
}

.gate__subdesc {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-outline);
  line-height: 1.8;
  margin-bottom: var(--space-2xl);
}

.gate__form {
  display: flex;
  gap: 0.625rem;
  margin-bottom: var(--space-md);
  max-width: 360px;
  margin-left: auto;
  margin-right: auto;
}

.gate__input {
  flex: 1;
  height: 48px;
  padding: 0 1.25rem;
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  background: rgba(18, 27, 76, 0.5);
  border: 1px solid rgba(63, 69, 108, 0.4);
  border-radius: var(--radius-lg);
  outline: none;
  transition: border-color var(--transition-fast);
}

.gate__input::placeholder {
  color: rgba(109, 115, 157, 0.6);
}

.gate__input:focus {
  border-color: rgba(175, 136, 255, 0.5);
}

.gate__btn {
  height: 48px;
  padding: 0 1.5rem;
  font-family: var(--font-headline);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: #fff;
  background: var(--color-primary-dim);
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: background var(--transition-fast);
  white-space: nowrap;
}

.gate__btn:hover {
  background: var(--color-primary);
}

.gate__error {
  font-size: 0.75rem;
  color: var(--color-level-advanced);
  margin-bottom: var(--space-sm);
}

.gate__footer {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-3xl);
  font-family: var(--font-label);
  font-size: 0.7rem;
  font-weight: 400;
  color: rgba(109, 115, 157, 0.5);
  letter-spacing: 0.02em;
}

.gate__dot {
  width: 2px;
  height: 2px;
  border-radius: 50%;
  background: rgba(109, 115, 157, 0.4);
}

@media (max-width: 480px) {
  .gate {
    padding-bottom: 2vh;
  }

  .gate__box {
    padding: var(--space-xl) var(--space-lg);
  }

  .gate__title {
    font-size: 1.3rem;
  }

  .gate__form {
    flex-direction: column;
    max-width: 100%;
  }

  .gate__btn {
    height: 48px;
  }
}

/* ── Skip Link ── */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-on-primary);
  background: var(--color-primary);
  border-radius: var(--radius-lg);
  text-decoration: none;
  z-index: 100;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
}

/* ── Search Clear Button ── */
/* ── Bookmark Filter Button ── */
.search__bookmark {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  margin-left: var(--space-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-lg);
  color: var(--color-border);
  background: rgba(23, 32, 86, 0.4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  cursor: pointer;
  transition: all var(--transition-fast);
}
.search__bookmark:hover { color: #fbbf24; border-color: rgba(251, 191, 36, 0.3); }
.search__bookmark--active { color: #fbbf24; background: rgba(251, 191, 36, 0.1); border-color: rgba(251, 191, 36, 0.4); }
html.light .search__bookmark { background: #fff; border-color: #d4d8e3; color: #d4d8e3; }
html.light .search__bookmark:hover { color: #f59e0b; border-color: rgba(245, 158, 11, 0.3); }
html.light .search__bookmark--active { color: #f59e0b; background: rgba(245, 158, 11, 0.06); border-color: rgba(245, 158, 11, 0.4); }

.search__clear {
  position: absolute;
  right: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  padding: 0;
  font-size: var(--font-size-sm);
  color: var(--color-outline);
  background: transparent;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.search__clear:hover {
  color: var(--color-text);
  background: rgba(226, 227, 255, 0.1);
}

/* ── Related Terms ── */
.card__section--related {
  padding-top: var(--space-md);
  border-top: 1px solid rgba(63, 69, 108, 0.3);
}

.related__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.related__pill {
  padding: 0.25rem 0.75rem;
  font-family: var(--font-label);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-tertiary-dim);
  background: rgba(90, 228, 208, 0.08);
  border: 1px solid rgba(90, 228, 208, 0.2);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.related__pill:hover {
  color: var(--color-tertiary);
  background: rgba(90, 228, 208, 0.15);
  border-color: rgba(90, 228, 208, 0.4);
  box-shadow: 0 0 10px rgba(90, 228, 208, 0.15);
}