/* ==========================================================================
   KOTOBA LAB (言葉ラボ) - Modern Dynamic Single Page Application Stylesheet
   Theme: Tokyo Cyber-Slate Glassmorphic UI with Fluid Responsiveness
   ========================================================================== */

/* 1. CSS Custom Properties / Design Tokens */
:root {
  /* Color Palette - Tokyo Dark (Default) */
  --bg-primary: #090d16;
  --bg-secondary: #0f172a;
  --bg-surface: rgba(18, 24, 38, 0.72);
  --bg-surface-elevated: rgba(26, 34, 52, 0.85);
  --bg-surface-hover: rgba(35, 46, 70, 0.9);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-border-hover: rgba(99, 102, 241, 0.45);
  --glass-backdrop-blur: blur(16px);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-tertiary: #64748b;
  --text-inverse: #090d16;

  /* Accent Gradients & Brand Colors */
  --accent-cyan: #38bdf8;
  --accent-indigo: #6366f1;
  --accent-purple: #a855f7;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;
  
  --gradient-brand: linear-gradient(135deg, #38bdf8 0%, #6366f1 50%, #c084fc 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
  --gradient-card-top: linear-gradient(180deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.01) 100%);

  /* Shadow & Elevation Tokens */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.4), 0 0 1px rgba(255, 255, 255, 0.1);
  --shadow-lg: 0 20px 40px -8px rgba(0, 0, 0, 0.55), 0 0 24px rgba(99, 102, 241, 0.2);
  --shadow-glow: 0 0 30px rgba(56, 189, 248, 0.25);

  /* Typography & Layout Spacing */
  --font-sans: 'Outfit', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Yu Gothic UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Menlo, Consolas, monospace;
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --transition-fast: 160ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 260ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 400ms cubic-bezier(0.16, 1, 0.3, 1);

  --container-max: 1280px;
}

/* Light Theme Variables */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-surface: rgba(255, 255, 255, 0.85);
  --bg-surface-elevated: rgba(255, 255, 255, 0.95);
  --bg-surface-hover: #ffffff;
  --glass-border: rgba(148, 163, 184, 0.22);
  --glass-border-hover: rgba(99, 102, 241, 0.6);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #94a3b8;
  --text-inverse: #ffffff;
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 8px 24px -4px rgba(15, 23, 42, 0.08), 0 0 1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 40px -8px rgba(15, 23, 42, 0.12), 0 0 20px rgba(99, 102, 241, 0.1);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  font-feature-settings: "palt" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  letter-spacing: 0.02em;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Ambient Background Lights */
.bg-ambient-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.45;
  will-change: transform;
}

.ambient-orb-1 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.35), transparent 70%);
  top: -100px;
  left: 10%;
  animation: floatOrb 22s ease-in-out infinite alternate;
}

.ambient-orb-2 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.3), transparent 70%);
  top: 30%;
  right: -50px;
  animation: floatOrb 26s ease-in-out infinite alternate-reverse;
}

.ambient-orb-3 {
  width: 450px;
  height: 450px;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.25), transparent 70%);
  bottom: 5%;
  left: 20%;
  animation: floatOrb 30s ease-in-out infinite alternate;
}

@keyframes floatOrb {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, 30px) scale(1.08); }
  100% { transform: translate(-30px, 50px) scale(0.95); }
}

/* 3. Header & Navigation */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  -webkit-backdrop-filter: var(--glass-backdrop-blur);
  border-bottom: 1px solid var(--glass-border);
  transition: all var(--transition-normal);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: inherit;
}

.brand-logo-badge {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.25rem;
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
  position: relative;
  overflow: hidden;
}

.brand-logo-badge::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.4) 0%, transparent 60%);
}

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

.brand-name {
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.brand-version-badge {
  font-size: 0.65rem;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.35);
  color: var(--accent-cyan);
  -webkit-text-fill-color: var(--accent-cyan);
  vertical-align: middle;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Action Buttons */
.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border);
  background: var(--bg-surface-elevated);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-action:hover {
  background: var(--bg-surface-hover);
  border-color: var(--glass-border-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn-action:active {
  transform: translateY(0);
}

.btn-action-primary {
  background: var(--gradient-brand);
  color: #ffffff;
  border: none;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-action-primary:hover {
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.55);
  transform: translateY(-1.5px);
  background: linear-gradient(135deg, #4dc7ff 0%, #7074ff 50%, #c88dfc 100%);
}

.btn-icon-only {
  width: 40px;
  height: 40px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
}

.badge-counter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  border-radius: var(--radius-full);
  background: var(--accent-indigo);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
}

/* 4. Main App Container */
.main-wrapper {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 2rem 1.5rem 5rem 1.5rem;
}

/* 5. Hero Banner Section */
.hero-section {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
  padding: 2.25rem 2.5rem;
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  -webkit-backdrop-filter: var(--glass-backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-brand);
}

.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.3);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 1rem;
}

.hero-badge-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 8px var(--accent-cyan);
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.8); }
}

.hero-title {
  font-size: clamp(2rem, 3.8vw, 2.85rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.hero-gradient-text {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.hero-description {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1.75rem;
}

.hero-metrics-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--glass-border);
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-number {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  font-feature-settings: "tnum" 1;
}

.metric-label {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

.hero-visual-card {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--glass-border);
}

.hero-banner-image {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  display: block;
  transition: transform var(--transition-slow);
}

.hero-visual-card:hover .hero-banner-image {
  transform: scale(1.03);
}

.hero-image-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 50%, rgba(9, 13, 22, 0.8) 100%);
  display: flex;
  align-items: flex-end;
  padding: 1.25rem;
  pointer-events: none;
}

.hero-image-caption {
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* 6. Learning Progress Bar Widget */
.learning-tracker-card {
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.5rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.tracker-left {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex: 1;
}

.tracker-icon {
  font-size: 1.6rem;
}

.tracker-details {
  flex: 1;
}

.tracker-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.35rem;
  font-size: 0.85rem;
  font-weight: 600;
}

.tracker-percent {
  color: var(--accent-cyan);
  font-weight: 700;
}

.progress-track {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-brand);
  border-radius: var(--radius-full);
  width: 0%;
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.tracker-quick-stats {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.tracker-pill {
  font-size: 0.8rem;
  color: var(--text-secondary);
  background: var(--bg-surface-elevated);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* 7. Interactive Controls & Search Toolbar */
.toolbar-section {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.search-and-presets-row {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.search-input-wrapper {
  flex: 1;
  position: relative;
}

.search-icon-decor {
  position: absolute;
  left: 1.15rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-tertiary);
  pointer-events: none;
  font-size: 1.1rem;
}

.glossary-search-input {
  width: 100%;
  padding: 0.9rem 3rem 0.9rem 3rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  outline: none;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.glossary-search-input:focus {
  border-color: var(--accent-indigo);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25), var(--shadow-sm);
  background: var(--bg-surface-elevated);
}

.glossary-search-input::placeholder {
  color: var(--text-tertiary);
}

.search-clear-btn {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  font-size: 1.1rem;
  padding: 4px;
  display: none;
}

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

.search-clear-btn.active {
  display: block;
}

/* Category Tabs Bar */
.category-tabs-container {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  overflow-x: auto;
  padding-bottom: 4px;
  scrollbar-width: none;
}

.category-tabs-container::-webkit-scrollbar {
  display: none;
}

.tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1.1rem;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: var(--radius-full);
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.tab-btn:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
  border-color: var(--glass-border-hover);
}

.tab-btn.active {
  background: var(--accent-indigo);
  border-color: var(--accent-indigo);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.tab-count-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 1px 7px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.15);
}

/* Secondary Filters & View Switchers */
.sub-filter-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 0.5rem;
}

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

.filter-chip {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: var(--radius-full);
  background: transparent;
  border: 1px solid var(--glass-border);
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-chip:hover {
  color: var(--text-secondary);
  border-color: var(--text-secondary);
}

.filter-chip.active {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  font-weight: 600;
}

.view-and-sort-controls {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.sort-select {
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 500;
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  outline: none;
  cursor: pointer;
}

.view-mode-toggle {
  display: flex;
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: 2px;
}

.view-toggle-btn {
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-tertiary);
  border-radius: 6px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.view-toggle-btn.active {
  background: var(--bg-surface-elevated);
  color: var(--accent-cyan);
  box-shadow: var(--shadow-sm);
}

/* 8. Active Filter Status & Result Count */
.results-indicator-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.results-count-bold {
  font-weight: 700;
  color: var(--text-primary);
  font-size: 1rem;
}

.filter-reset-link {
  color: var(--accent-cyan);
  background: none;
  border: none;
  font-size: 0.85rem;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.filter-reset-link:hover {
  color: #7dd3fc;
}

/* 9. Glossary Cards Grid & List Layouts */
.glossary-cards-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 1.5rem;
  transition: opacity var(--transition-fast);
}

/* List View Variant */
.glossary-cards-container.view-list {
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

/* Individual Term Card (Rich Glassmorphic Design) */
.term-card {
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  -webkit-backdrop-filter: var(--glass-backdrop-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
  cursor: pointer;
  overflow: hidden;
}

.term-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient, var(--gradient-brand));
  opacity: 0.4;
  transition: opacity var(--transition-fast), height var(--transition-fast);
}

.term-card:hover {
  transform: translateY(-4px);
  border-color: var(--glass-border-hover);
  box-shadow: var(--shadow-lg);
  background: var(--bg-surface-elevated);
}

.term-card:hover::before {
  opacity: 1;
  height: 4px;
}

/* Category Accent Gradients per Card */
.term-card[data-category="ai"] { --accent-gradient: linear-gradient(90deg, #38bdf8, #818cf8); }
.term-card[data-category="web"] { --accent-gradient: linear-gradient(90deg, #10b981, #06b6d4); }
.term-card[data-category="design"] { --accent-gradient: linear-gradient(90deg, #f43f5e, #ec4899); }
.term-card[data-category="trend"] { --accent-gradient: linear-gradient(90deg, #a855f7, #6366f1); }

.card-header-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.card-category-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
}

.card-actions-inline {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-card-fav {
  background: transparent;
  border: none;
  font-size: 1.15rem;
  cursor: pointer;
  color: var(--text-tertiary);
  transition: transform var(--transition-fast), color var(--transition-fast);
  padding: 4px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-card-fav:hover {
  color: var(--accent-rose);
  transform: scale(1.15);
}

.btn-card-fav.bookmarked {
  color: var(--accent-rose);
  animation: heartPop 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes heartPop {
  0% { transform: scale(0.8); }
  50% { transform: scale(1.3); }
  100% { transform: scale(1); }
}

.term-furigana {
  font-size: 0.75rem;
  color: var(--accent-cyan);
  font-weight: 500;
  margin-bottom: 0.15rem;
}

.term-title {
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
  letter-spacing: -0.01em;
}

.term-en-title {
  font-size: 0.825rem;
  font-weight: 500;
  color: var(--text-tertiary);
  margin-bottom: 0.85rem;
  font-family: 'Outfit', sans-serif;
}

.term-summary {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
}

.card-footer-tags {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: auto;
  padding-top: 0.85rem;
  border-top: 1px solid var(--glass-border);
}

.tag-list-chips {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.tag-mini {
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-tertiary);
}

.card-click-hint {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-indigo);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  transition: transform var(--transition-fast);
}

.term-card:hover .card-click-hint {
  transform: translateX(3px);
  color: var(--accent-cyan);
}

/* List View Customizations */
.view-list .term-card {
  padding: 1rem 1.5rem;
  flex-direction: row;
  align-items: center;
  gap: 1.5rem;
}

.view-list .term-card::before {
  top: 0;
  bottom: 0;
  left: 0;
  width: 3px;
  height: 100%;
}

.view-list .card-header-meta {
  margin-bottom: 0;
  flex-direction: column;
  align-items: flex-start;
  min-width: 140px;
}

.view-list .term-main-info {
  flex: 1;
  min-width: 250px;
}

.view-list .term-summary {
  -webkit-line-clamp: 2;
  margin-bottom: 0;
}

.view-list .card-footer-tags {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
  min-width: 200px;
  justify-content: flex-end;
}

/* 10. Empty State */
.empty-state-card {
  grid-column: 1 / -1;
  text-align: center;
  padding: 4rem 2rem;
  background: var(--bg-surface);
  border: 1px dashed var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: var(--glass-backdrop-blur);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.empty-state-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.empty-state-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto 1.5rem auto;
}

/* 11. Native HTML Modal Dialog Styling (Modern @starting-style Top-layer) */
dialog.custom-modal {
  margin: auto;
  border: 1px solid var(--glass-border-hover);
  border-radius: var(--radius-lg);
  background: var(--bg-surface-elevated);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  color: var(--text-primary);
  max-width: 760px;
  width: calc(100% - 2rem);
  box-shadow: 0 25px 60px -15px rgba(0, 0, 0, 0.7), 0 0 30px rgba(99, 102, 241, 0.25);
  overflow: hidden;
  outline: none;
  padding: 0;
  
  /* Modern CSS transition with top-layer allow-discrete */
  opacity: 0;
  transform: scale(0.94) translateY(15px);
  transition: opacity var(--transition-normal), transform var(--transition-normal), overlay var(--transition-normal) allow-discrete, display var(--transition-normal) allow-discrete;
}

dialog.custom-modal[open] {
  opacity: 1;
  transform: scale(1) translateY(0);
}

@starting-style {
  dialog.custom-modal[open] {
    opacity: 0;
    transform: scale(0.94) translateY(15px);
  }
}

dialog.custom-modal::backdrop {
  background: rgba(9, 13, 22, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  transition: opacity var(--transition-normal), overlay var(--transition-normal) allow-discrete, display var(--transition-normal) allow-discrete;
}

dialog.custom-modal[open]::backdrop {
  opacity: 1;
}

@starting-style {
  dialog.custom-modal[open]::backdrop {
    opacity: 0;
  }
}

.modal-header-bar {
  padding: 1.5rem 1.75rem 1.25rem 1.75rem;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.02);
}

.modal-title-group {
  flex: 1;
}

.modal-badge-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
}

.modal-title {
  font-size: 1.75rem;
  font-weight: 800;
  line-height: 1.25;
}

.modal-en-title {
  font-size: 0.95rem;
  color: var(--text-tertiary);
  font-family: 'Outfit', sans-serif;
  margin-top: 0.2rem;
}

.modal-actions-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-modal-close {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all var(--transition-fast);
}

.btn-modal-close:hover {
  background: rgba(255, 255, 255, 0.12);
  color: var(--text-primary);
}

.modal-body-content {
  padding: 1.75rem;
  max-height: 72vh;
  overflow-y: auto;
  overscroll-behavior: contain;
}

/* Audio Pronunciation Bar */
.audio-pronounce-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.25);
  border-radius: var(--radius-sm);
  margin-bottom: 1.5rem;
}

.audio-pronounce-left {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.soundwave-animation {
  display: inline-flex;
  align-items: flex-end;
  gap: 3px;
  height: 18px;
}

.soundwave-bar {
  width: 3px;
  background: var(--accent-cyan);
  border-radius: 2px;
  height: 4px;
  transition: height 0.2s ease;
}

.soundwave-animation.playing .soundwave-bar:nth-child(1) { animation: wave 0.8s infinite ease-in-out; }
.soundwave-animation.playing .soundwave-bar:nth-child(2) { animation: wave 0.8s infinite 0.15s ease-in-out; }
.soundwave-animation.playing .soundwave-bar:nth-child(3) { animation: wave 0.8s infinite 0.3s ease-in-out; }
.soundwave-animation.playing .soundwave-bar:nth-child(4) { animation: wave 0.8s infinite 0.45s ease-in-out; }

@keyframes wave {
  0%, 100% { height: 4px; }
  50% { height: 18px; }
}

.modal-section-block {
  margin-bottom: 1.5rem;
}

.modal-section-heading {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--glass-border);
}

.modal-text-lead {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-secondary);
  white-space: pre-line;
}

/* Pros and Cons Matrix */
.merit-demerit-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1rem;
}

.merit-box, .demerit-box {
  padding: 1rem 1.2rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
}

.merit-box {
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.demerit-box {
  background: rgba(244, 63, 94, 0.08);
  border: 1px solid rgba(244, 63, 94, 0.25);
}

.box-title-merit {
  font-weight: 700;
  color: var(--accent-emerald);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.box-title-demerit {
  font-weight: 700;
  color: var(--accent-rose);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.box-bullet-list {
  padding-left: 1.2rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.box-bullet-list li {
  margin-bottom: 0.35rem;
}

/* Code Snippet Block */
.code-box-wrapper {
  background: #050811;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #38bdf8;
  overflow-x: auto;
  line-height: 1.6;
  white-space: pre-wrap;
}

/* Related Terms Pill Cloud */
.related-terms-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.5rem;
}

.related-term-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.related-term-chip:hover {
  background: var(--accent-indigo);
  border-color: var(--accent-indigo);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

/* Modal Footer */
.modal-footer-bar {
  padding: 1.1rem 1.75rem;
  background: rgba(255, 255, 255, 0.02);
  border-top: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

/* 12. Interactive Mini-Quiz Modal / Flashcard Engine */
.quiz-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.quiz-header-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--glass-border);
}

.quiz-question-box {
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.quiz-question-label {
  font-size: 0.8rem;
  color: var(--accent-cyan);
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.quiz-question-text {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.5;
}

.quiz-options-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.quiz-option-btn {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  text-align: left;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.quiz-option-btn:hover:not(:disabled) {
  background: var(--bg-surface-hover);
  border-color: var(--accent-indigo);
  transform: translateX(4px);
}

.quiz-option-marker {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8rem;
  color: var(--text-secondary);
  flex-shrink: 0;
}

.quiz-option-btn.correct {
  background: rgba(16, 185, 129, 0.15) !important;
  border-color: var(--accent-emerald) !important;
  color: #34d399 !important;
}

.quiz-option-btn.wrong {
  background: rgba(244, 63, 94, 0.15) !important;
  border-color: var(--accent-rose) !important;
  color: #fb7185 !important;
}

.quiz-feedback-box {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  display: none;
  animation: fadeIn 0.3s ease;
}

.quiz-feedback-box.active {
  display: block;
}

.quiz-feedback-box.is-correct {
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid var(--accent-emerald);
  color: #34d399;
}

.quiz-feedback-box.is-wrong {
  background: rgba(244, 63, 94, 0.12);
  border: 1px solid var(--accent-rose);
  color: #fb7185;
}

/* 13. Add Term Form Modal */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-group-full {
  grid-column: 1 / -1;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-input, .form-textarea, .form-select {
  padding: 0.75rem 1rem;
  font-family: inherit;
  font-size: 0.95rem;
  background: var(--bg-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  outline: none;
  transition: all var(--transition-fast);
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
  border-color: var(--accent-indigo);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.form-textarea {
  min-height: 90px;
  resize: vertical;
}

/* 14. Toast Notification Popup */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  pointer-events: none;
}

.toast-message {
  padding: 0.85rem 1.4rem;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  backdrop-filter: blur(16px);
  border: 1px solid var(--accent-indigo);
  color: var(--text-primary);
  font-size: 0.9rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  animation: slideToast 0.35s cubic-bezier(0.16, 1, 0.3, 1), fadeOutToast 0.4s 2.6s forwards;
  pointer-events: auto;
}

@keyframes slideToast {
  from { transform: translateY(20px) scale(0.9); opacity: 0; }
  to { transform: translateY(0) scale(1); opacity: 1; }
}

@keyframes fadeOutToast {
  to { opacity: 0; transform: translateY(-10px); }
}

/* 15. Footer */
.app-footer {
  margin-top: 4rem;
  padding: 2.5rem 1.5rem;
  border-top: 1px solid var(--glass-border);
  background: var(--bg-surface);
  backdrop-filter: var(--glass-backdrop-blur);
  text-align: center;
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-nav {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  font-size: 0.85rem;
  color: var(--text-tertiary);
}

.footer-nav a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-nav a:hover {
  color: var(--accent-cyan);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-tertiary);
}

/* 16. Responsive Media Queries */
@media (max-width: 900px) {
  .hero-section {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 1.75rem;
  }
  .learning-tracker-card {
    flex-direction: column;
    align-items: stretch;
  }
  .tracker-quick-stats {
    justify-content: space-between;
  }
  .merit-demerit-grid {
    grid-template-columns: 1fr;
  }
  .form-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-container {
    padding: 0.75rem 1rem;
  }
  .brand-tagline {
    display: none;
  }
  .btn-action span.btn-label {
    display: none;
  }
  .hero-title {
    font-size: 1.75rem;
  }
  .glossary-cards-container {
    grid-template-columns: 1fr;
  }
  .search-and-presets-row {
    flex-direction: column;
  }
  .toast-container {
    left: 1rem;
    right: 1rem;
    bottom: 1rem;
  }
}

/* Reduced Motion Preference Accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .ambient-orb {
    display: none;
  }
}