/* ========================================
   しろくまパワー Design System
   Blazor Hybrid Edition
   ======================================== */

:root {
  /* Brand hues as RGB triplets so every translucent rgba() follows the active skin.
     Skins re-tint the whole UI by overriding just these (plus the solid vars below). */
  --accent-rgb: 56, 189, 248;     /* primary (cyan) */
  --secondary-rgb: 129, 140, 248; /* indigo */
  --tertiary-rgb: 167, 139, 250;  /* violet */
  --success-rgb: 52, 211, 153;    /* green */
  --success2-rgb: 34, 211, 238;   /* teal-cyan */
  --warning-rgb: 251, 191, 36;    /* amber */
  --danger-rgb: 248, 113, 113;    /* red */
  --surface-sunken: rgba(0, 0, 0, 0.2); /* inset tint behind example sentences */
  --on-accent: white;            /* text/icon color placed on solid accent buttons */
  --science-text: var(--accent-tertiary); /* readable accent text for tip/science titles */
  --nav-bg: rgba(11, 14, 23, 0.85); /* sticky top nav + mobile tab bar backdrop */

  /* Color Palette - Arctic Theme */
  --bg-primary: #0b0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2030;
  --bg-card-hover: #222d42;
  --bg-elevated: #1e2a3d;
  --bg-glass: rgba(26, 32, 48, 0.8);

  --text-primary: #f0f4ff;
  --text-secondary: #8b99b8;
  --text-muted: #5a6784;
  --text-accent: #7dd3fc;

  /* Accent Colors */
  --accent-primary: #38bdf8;
  --accent-primary-dark: #0ea5e9;
  --accent-secondary: #818cf8;
  --accent-tertiary: #a78bfa;
  --accent-success: #34d399;
  --accent-success-dark: #059669;
  --accent-warning: #fbbf24;
  --accent-danger: #f87171;
  --accent-danger-dark: #dc2626;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  --gradient-secondary: linear-gradient(135deg, #818cf8 0%, #a78bfa 100%);
  --gradient-success: linear-gradient(135deg, #34d399 0%, #22d3ee 100%);
  --gradient-warm: linear-gradient(135deg, #fbbf24 0%, #f87171 100%);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
  --gradient-card: linear-gradient(135deg, rgba(var(--accent-rgb),0.1) 0%, rgba(var(--secondary-rgb),0.1) 100%);
  --gradient-glow: radial-gradient(ellipse at 50% 0%, rgba(var(--accent-rgb),0.15) 0%, transparent 60%);

  /* Borders */
  --border-subtle: rgba(var(--accent-rgb), 0.1);
  --border-accent: rgba(var(--accent-rgb), 0.3);
  --border-hover: rgba(var(--accent-rgb), 0.5);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px rgba(var(--accent-rgb),0.2);
  --shadow-glow-strong: 0 0 30px rgba(var(--accent-rgb),0.3);

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

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Typography */
  --font-ja: 'M PLUS Rounded 1c', 'Hiragino Sans', 'Meiryo', sans-serif;
  --font-en: 'Inter', sans-serif;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --transition-spring: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ========================================
   Base Styles
   ======================================== */

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-ja);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
  /* Safe area padding for iOS notch/dynamic island */
  padding-top: env(safe-area-inset-top);
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
  padding-bottom: env(safe-area-inset-bottom);
}

/* body::before glow gradient removed for WebView compatibility */

#app {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  padding-bottom: 100px;
}

/* ========================================
   Scrollbar
   ======================================== */

::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-primary);
  border-radius: var(--radius-full);
}

/* ========================================
   Navigation
   ======================================== */

#main-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) 0;
  position: sticky;
  top: 0;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 100;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: var(--space-xl);
  transition: transform 0.3s ease;
}

#main-nav.nav-hidden {
  transform: translateY(-100%);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.brand-icon {
  font-size: 1.8rem;
  animation: float 3s ease-in-out infinite;
}

.brand-text {
  font-size: 1.2rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: var(--space-xs);
}

.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: var(--space-sm) var(--space-md);
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  font-family: var(--font-ja);
  font-size: 0.7rem;
  text-decoration: none;
}

.nav-icon {
  font-size: 1.2rem;
  transition: transform var(--transition-spring);
}

.nav-btn:hover {
  color: var(--text-primary);
  background: rgba(var(--accent-rgb), 0.1);
}

.nav-btn:hover .nav-icon {
  transform: scale(1.2);
}

/* Active nav button: supports both manual .active and Blazor NavLink active class */
.nav-btn.active,
.nav-btn.active:hover {
  color: var(--accent-primary);
  background: rgba(var(--accent-rgb), 0.15);
}

.nav-streak {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  background: rgba(var(--warning-rgb), 0.1);
  border: 1px solid rgba(var(--warning-rgb), 0.2);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
}

.streak-flame {
  font-size: 1.2rem;
  animation: pulse 2s ease-in-out infinite;
}

.streak-count {
  font-weight: 700;
  color: var(--accent-warning);
}

.streak-label {
  color: var(--text-secondary);
  font-size: 0.75rem;
}

/* ========================================
   Page Transitions (Blazor routing)
   ======================================== */

.page-content {
  animation: fadeIn 0.4s ease;
}

/* ========================================
   Dashboard
   ======================================== */

.dashboard-hero {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
  padding: var(--space-2xl);
  background: var(--gradient-hero);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
  margin-bottom: var(--space-xl);
  position: relative;
  overflow: hidden;
}

.dashboard-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(var(--accent-rgb),0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-bear {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.bear-animation {
  font-size: 5rem;
  animation: bearBounce 2s ease-in-out infinite;
  filter: drop-shadow(0 0 20px rgba(var(--accent-rgb),0.3));
}

.hero-speech-bubble {
  background: var(--bg-card);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-accent);
  position: relative;
  font-size: 0.9rem;
  color: var(--text-accent);
  max-width: 200px;
  text-align: center;
}

.hero-speech-bubble::before {
  content: '';
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
  border-bottom: 8px solid var(--border-accent);
}

.hero-greeting {
  font-size: 2rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-top: var(--space-sm);
}

/* Dashboard Cards */
.dashboard-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.dash-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.dash-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-review::before { background: var(--gradient-warm); }
.card-new::before { background: var(--gradient-primary); }
.card-mastered::before { background: var(--gradient-success); }
.card-total::before { background: var(--gradient-secondary); }

.dash-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
}

.card-number {
  font-size: 2.5rem;
  font-weight: 900;
  display: block;
  line-height: 1;
}

.card-review .card-number { color: var(--accent-warning); }
.card-new .card-number { color: var(--accent-primary); }
.card-mastered .card-number { color: var(--accent-success); }
.card-total .card-number { color: var(--accent-secondary); }

.card-label {
  color: var(--text-secondary);
  font-size: 0.85rem;
  display: block;
  margin-top: var(--space-xs);
}

.card-action {
  margin-top: var(--space-md);
  font-size: 0.8rem;
  color: var(--accent-primary);
  font-weight: 600;
}

/* Science Tip */
.science-tip {
  background: linear-gradient(135deg, rgba(var(--secondary-rgb),0.1) 0%, rgba(var(--tertiary-rgb),0.1) 100%);
  border: 1px solid rgba(var(--secondary-rgb),0.2);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.tip-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.tip-icon {
  font-size: 1.5rem;
}

.tip-title {
  font-weight: 700;
  color: var(--science-text);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tip-content {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* Today's Progress */
.today-progress {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.today-progress h3 {
  margin-bottom: var(--space-md);
  font-size: 1rem;
}

.progress-bar-container {
  height: 12px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-sm);
}

.progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
  position: relative;
}

.progress-bar::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.2) 50%, transparent 100%);
  animation: shimmer 2s infinite;
}

.progress-info {
  text-align: right;
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* Level Display */
.level-display {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.level-info {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.level-badge {
  background: var(--gradient-primary);
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  font-weight: 800;
  font-size: 0.9rem;
}

.level-title {
  font-weight: 700;
  color: var(--text-accent);
}

.xp-bar-container {
  height: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-xs);
}

.xp-bar {
  height: 100%;
  background: var(--gradient-secondary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

.xp-text {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ========================================
   Flashcard Study
   ======================================== */

.study-header {
  margin-bottom: var(--space-xl);
}

.study-header h2 {
  font-size: 1.5rem;
  margin-bottom: var(--space-md);
}

.study-controls {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.select-input {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-ja);
  font-size: 0.85rem;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.select-input:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.study-progress-bar {
  height: 6px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-xl);
  position: relative;
  overflow: hidden;
}

.study-progress-fill {
  height: 100%;
  background: var(--gradient-success);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.study-progress-text {
  position: absolute;
  right: 0;
  top: 12px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Flashcard */
.flashcard-container {
  max-width: 500px;
  margin: 0 auto;
}

.flashcard {
  width: 100%;
  cursor: pointer;
  outline: none;
}

.flashcard-inner {
  width: 100%;
}

.flashcard-front,
.flashcard-back {
  width: 100%;
  border-radius: var(--radius-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-xl) var(--space-xl) var(--space-xl);
  border: 1px solid var(--border-accent);
  overflow: hidden;
}

.flashcard-front {
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-elevated) 100%);
  box-shadow: var(--shadow-glow);
}

.flashcard-back {
  display: none;
  background: linear-gradient(135deg, rgba(var(--success-rgb),0.1) 0%, rgba(var(--success2-rgb),0.1) 100%);
  border-color: rgba(var(--success-rgb),0.3);
}

.flashcard.flipped .flashcard-front {
  display: none;
}

.flashcard.flipped .flashcard-back {
  display: flex;
}

.flashcard-top {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  padding-top: var(--space-md);
}

.flashcard-middle {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: var(--space-md) 0;
}

.flashcard-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  padding-bottom: var(--space-sm);
}

.flashcard-category {
  font-size: 0.75rem;
  color: var(--accent-primary);
  background: rgba(var(--accent-rgb),0.1);
  padding: 2px 12px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-sm);
}

.flashcard-word-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

.flashcard-word {
  font-size: clamp(1rem, 4vw, 2.2rem);
  font-weight: 900;
  text-align: center;
  line-height: 1.3;
  overflow-wrap: break-word;
  word-break: break-word;
  max-width: 100%;
}

.flashcard-reading {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-top: var(--space-sm);
}

.flashcard-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  animation: pulse 2s ease-in-out infinite;
}

.flashcard-answer {
  font-size: clamp(1rem, 4vw, 2rem);
  font-weight: 700;
  color: var(--accent-success);
  text-align: center;
  overflow-wrap: break-word;
  word-break: break-word;
  max-width: 100%;
}

.flashcard-answer ruby {
  ruby-position: over;
}

.flashcard-answer rt {
  font-size: 0.45em;
  font-weight: 400;
  color: var(--text-secondary);
}

.flashcard-definition {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.5;
  margin-bottom: var(--space-xs);
}

.definition-row {
  padding: 2px 0;
}

.flashcard-example {
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.6;
  padding: var(--space-sm) var(--space-md);
  background: var(--surface-sunken);
  border-radius: var(--radius-md);
  max-width: 100%;
}

.tts-btn {
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  opacity: 0.7;
  transition: opacity 0.2s, transform 0.2s;
}
.tts-btn:hover {
  opacity: 1;
  transform: scale(1.15);
}
.tts-btn-sm {
  font-size: 1rem;
  padding: 2px 4px;
  flex-shrink: 0;
}
.example-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.flashcard-science {
  font-size: 0.75rem;
  color: var(--science-text);
  margin-top: var(--space-md);
  font-style: italic;
}

/* Flashcard Image */
.flashcard-image-container {
  position: relative;
  width: 120px;
  height: 120px;
  margin: var(--space-sm) 0;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.flashcard-image {
  width: 120px;
  height: 120px;
  object-fit: contain;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.image-spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border-subtle);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.image-regenerate-btn {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 28px;
  height: 28px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.5);
  color: var(--text-primary);
  cursor: pointer;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.flashcard-image-container:hover .image-regenerate-btn {
  opacity: 1;
}

.image-regenerate-btn:hover {
  background: rgba(var(--accent-rgb), 0.6);
}

.flashcard-image-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.image-retry-btn {
  padding: 2px 10px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--accent-primary);
  cursor: pointer;
  font-size: 0.7rem;
  font-family: var(--font-ja);
  transition: all var(--transition-fast);
}

.image-retry-btn:hover {
  background: rgba(var(--accent-rgb), 0.1);
  border-color: var(--accent-primary);
}

/* SRS Layout Positions */
.study-layout {
  display: flex;
  flex-direction: column;
}

.study-layout.srs-layout-top {
  flex-direction: column-reverse !important;
}

.study-layout.srs-layout-left {
  flex-direction: row-reverse !important;
  align-items: flex-start;
  gap: 0;
  justify-content: center;
}

.study-layout.srs-layout-right {
  flex-direction: row !important;
  align-items: flex-start;
  gap: 0;
  justify-content: center;
}

.srs-layout-left .flashcard-container,
.srs-layout-right .flashcard-container {
  flex: 1;
  min-width: 0;
}

.srs-layout-left .srs-buttons,
.srs-layout-right .srs-buttons {
  max-width: 80px;
  margin: 0;
}

.srs-layout-left .srs-btn-group,
.srs-layout-right .srs-btn-group {
  flex-direction: column;
  gap: var(--space-xs);
}

.srs-layout-left .srs-btn,
.srs-layout-right .srs-btn {
  flex-direction: column;
  padding: var(--space-xs) var(--space-xs);
  gap: 2px;
}

.srs-layout-left .srs-text,
.srs-layout-right .srs-text {
  font-size: 0.6rem;
}

.srs-layout-left .srs-interval,
.srs-layout-right .srs-interval {
  font-size: 0.55rem;
}

.srs-layout-left .srs-prompt,
.srs-layout-right .srs-prompt {
  font-size: 0.7rem;
}


/* SRS Buttons */
.srs-buttons {
  max-width: 500px;
  margin: 24px auto 0;
  text-align: center;
  position: relative;
  z-index: 10;
}

.srs-prompt {
  color: var(--text-secondary);
  margin-top: var(--space-sm);
  margin-bottom: 0;
  font-size: 0.85rem;
}

.srs-btn-group {
  display: flex;
  gap: var(--space-xs);
}

.srs-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: var(--space-sm) var(--space-xs);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-normal);
  font-family: var(--font-ja);
  white-space: nowrap;
}

.srs-emoji {
  font-size: 1.1rem;
}

.srs-text {
  font-size: 0.7rem;
  font-weight: 600;
}

.srs-interval {
  font-size: 0.6rem;
  color: var(--text-muted);
}

.srs-again:hover { border-color: var(--accent-danger); background: rgba(var(--danger-rgb),0.1); }
.srs-hard:hover { border-color: var(--accent-warning); background: rgba(var(--warning-rgb),0.1); }
.srs-good:hover { border-color: var(--accent-primary); background: rgba(var(--accent-rgb),0.1); }
.srs-easy:hover { border-color: var(--accent-success); background: rgba(var(--success-rgb),0.1); }

.srs-btn:active {
  transform: scale(0.95);
}

/* Study Empty State */
.study-empty {
  text-align: center;
  padding: var(--space-2xl);
}

.empty-bear {
  font-size: 4rem;
  margin-bottom: var(--space-md);
  animation: bearBounce 2s ease-in-out infinite;
}

.study-empty h3 {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
  color: var(--accent-success);
}

.study-empty p {
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

/* ========================================
   Quiz Mode
   ======================================== */

.quiz-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.quiz-header h2 {
  font-size: 1.8rem;
}

.quiz-subtitle {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: var(--space-xs);
}

.quiz-modes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-lg);
}

.quiz-mode-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
}

.quiz-mode-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.qm-icon {
  font-size: 3rem;
  margin-bottom: var(--space-md);
}

.quiz-mode-card h3 {
  font-size: 1.1rem;
  margin-bottom: var(--space-xs);
}

.quiz-mode-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.qm-badge {
  display: inline-block;
  margin-top: var(--space-md);
  font-size: 0.7rem;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  background: rgba(var(--accent-rgb),0.15);
  color: var(--accent-primary);
  font-weight: 600;
}

/* Quiz Area */
.quiz-area {
  max-width: 600px;
  margin: 0 auto;
}

.quiz-score-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-xl);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.quiz-score {
  font-weight: 700;
}

.score-correct {
  color: var(--accent-success);
  font-size: 1.2rem;
}

.score-total {
  color: var(--text-secondary);
}

.quiz-timer {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-family: var(--font-en);
}

.quiz-question-container {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-accent);
  margin-bottom: var(--space-xl);
  min-height: 150px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.quiz-question {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.3;
}

.quiz-question-sub {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: var(--space-sm);
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.quiz-option {
  padding: var(--space-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  font-family: var(--font-ja);
  font-size: 1rem;
  color: var(--text-primary);
  text-align: center;
}

.quiz-option:hover:not(.disabled) {
  border-color: var(--accent-primary);
  background: rgba(var(--accent-rgb),0.1);
  transform: translateY(-2px);
}

.quiz-option.correct {
  border-color: var(--accent-success) !important;
  background: rgba(var(--success-rgb),0.2) !important;
  animation: correctPulse 0.5s ease;
}

.quiz-option.incorrect {
  border-color: var(--accent-danger) !important;
  background: rgba(var(--danger-rgb),0.2) !important;
  animation: shake 0.5s ease;
}

.quiz-option.disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Quiz Feedback */
.quiz-feedback {
  text-align: center;
  padding: var(--space-lg);
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  margin-bottom: var(--space-lg);
}

.feedback-icon {
  font-size: 3rem;
  margin-bottom: var(--space-sm);
}

.feedback-text {
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
  font-size: 1rem;
}

/* Quiz Results */
.quiz-results {
  text-align: center;
  padding: var(--space-2xl);
}

.results-bear {
  font-size: 4rem;
  margin-bottom: var(--space-md);
  animation: bearBounce 2s ease-in-out infinite;
}

.results-score {
  font-size: 3rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: var(--space-md) 0;
}

.results-details {
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

.results-actions {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
}

/* ========================================
   Word List
   ======================================== */

.wordlist-header {
  margin-bottom: var(--space-xl);
}

.wordlist-header h2 {
  margin-bottom: var(--space-md);
}

.wordlist-controls {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.search-input {
  flex: 1;
  min-width: 200px;
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-ja);
  font-size: 0.9rem;
  transition: border-color var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.wordlist-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-md);
}

.word-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  transition: all var(--transition-normal);
  position: relative;
}

.word-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.word-card.has-image {
  border-color: rgba(var(--accent-rgb),0.3);
}

.word-card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.word-card-top-left {
  flex: 1;
  min-width: 0;
}

.word-card-thumb {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  object-fit: cover;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
  animation: thumb-appear 0.4s ease-out;
}

.word-card-thumb-placeholder {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.4rem;
  opacity: 0.3;
}

@keyframes thumb-appear {
  from { opacity: 0; transform: scale(0.8); }
  to { opacity: 1; transform: scale(1); }
}

.word-japanese {
  font-size: 1.5rem;
  font-weight: 800;
}

.word-strength {
  display: flex;
  gap: 2px;
}

.strength-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--bg-secondary);
}

.strength-dot.filled {
  background: var(--accent-success);
}

.strength-dot.half {
  background: var(--accent-warning);
}

.word-reading {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: var(--space-xs);
}

.word-english {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-sm);
}

.word-card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
}

.word-category-tag {
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: rgba(var(--accent-rgb),0.1);
  color: var(--accent-primary);
}

.word-due-date {
  color: var(--text-muted);
}

.word-due-date.overdue {
  color: var(--accent-danger);
}

.word-card-actions {
  display: flex;
  gap: var(--space-xs);
  margin-top: var(--space-sm);
}

.word-action-btn {
  padding: 4px 8px;
  border: none;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.05);
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.7rem;
  transition: all var(--transition-fast);
  font-family: var(--font-ja);
}

.word-action-btn:hover {
  background: rgba(var(--accent-rgb),0.1);
  color: var(--accent-primary);
}

.word-action-btn.delete:hover {
  background: rgba(var(--danger-rgb),0.1);
  color: var(--accent-danger);
}

/* ========================================
   Statistics
   ======================================== */

.stats-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.stats-header p {
  color: var(--text-secondary);
}

.stats-overview {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-align: center;
  transition: all var(--transition-normal);
}

.stat-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.stat-icon {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
}

.stat-value {
  font-size: 2rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: var(--space-xs);
}

.stats-section {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.stats-section h3 {
  margin-bottom: var(--space-lg);
}

/* Heatmap — GitHub-style Calendar (table layout) */
.heatmap-scroll {
  overflow-x: auto;
  padding-bottom: var(--space-xs);
}

.heatmap-table {
  border-spacing: 3px;
  border-collapse: separate;
  width: 100%;
}

.heatmap-table td,
.heatmap-table th {
  padding: 0;
}

.heatmap-month-label {
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--text-muted);
  text-align: left;
  padding-bottom: 4px !important;
  white-space: nowrap;
}

.heatmap-day-label {
  font-size: 0.65rem;
  color: var(--text-muted);
  text-align: right;
  padding-right: 6px !important;
  width: 28px;
  white-space: nowrap;
}

.heatmap-cell {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  transition: all 0.15s ease;
  position: relative;
}

.heatmap-cell:hover {
  transform: scale(1.5);
  z-index: 10;
}

.heatmap-cell:hover::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-size: 0.7rem;
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
  border: 1px solid var(--border-accent);
  box-shadow: 0 4px 12px rgba(0,0,0,0.5);
  pointer-events: none;
}

.heatmap-empty {
  background: transparent;
}

.heatmap-0 {
  background: var(--bg-secondary);
}

.heatmap-1 {
  background: rgba(var(--accent-rgb), 0.18);
  box-shadow: inset 0 0 0 1px rgba(var(--accent-rgb), 0.12);
}

.heatmap-2 {
  background: rgba(var(--accent-rgb), 0.38);
  box-shadow: 0 0 4px rgba(var(--accent-rgb), 0.15);
}

.heatmap-3 {
  background: rgba(var(--accent-rgb), 0.62);
  box-shadow: 0 0 8px rgba(var(--accent-rgb), 0.25);
}

.heatmap-4 {
  background: rgba(var(--accent-rgb), 0.88);
  box-shadow: 0 0 12px rgba(var(--accent-rgb), 0.4), 0 0 4px rgba(var(--accent-rgb), 0.6);
}

.heatmap-legend {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  justify-content: flex-end;
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: var(--space-sm);
}

.heatmap-box {
  width: 12px;
  height: 12px;
  border-radius: 3px;
}

/* Category Progress */
.category-progress-item {
  margin-bottom: var(--space-lg);
}

.cat-progress-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-xs);
  font-size: 0.85rem;
}

.cat-progress-bar {
  height: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.cat-progress-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

/* Clickable tag rows in the Stats tag breakdown (deep-link to the filtered Word List) */
.category-progress-item--clickable {
  cursor: pointer;
  border-radius: var(--radius-md, 8px);
  padding: var(--space-xs) var(--space-sm);
  margin: 0 calc(-1 * var(--space-sm)) var(--space-sm);
  transition: background var(--transition-fast, 0.15s);
}

.category-progress-item--clickable:hover,
.category-progress-item--clickable:focus-visible {
  background: var(--bg-secondary);
  outline: none;
}

/* Memory Chart */
.memory-chart {
  display: flex;
  align-items: flex-end;
  gap: var(--space-sm);
  height: 200px;
  padding-top: var(--space-md);
}

.memory-bar-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  height: 100%;
  justify-content: flex-end;
}

.memory-bar {
  width: 100%;
  max-width: 60px;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  transition: height var(--transition-slow);
  min-height: 4px;
}

.memory-bar-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-align: center;
}

.memory-bar-count {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
}

/* Science Cards */
.science-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.science-card {
  background: linear-gradient(135deg, rgba(var(--secondary-rgb),0.05) 0%, rgba(var(--tertiary-rgb),0.05) 100%);
  border: 1px solid rgba(var(--secondary-rgb),0.15);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
}

.science-card-title {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: var(--space-xs);
  color: var(--science-text);
}

.science-card-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.science-section {
  background: linear-gradient(135deg, rgba(var(--secondary-rgb),0.05) 0%, rgba(var(--tertiary-rgb),0.05) 100%);
  border-color: rgba(var(--secondary-rgb),0.15);
}

/* ========================================
   Add Word Form
   ======================================== */

.add-header {
  margin-bottom: var(--space-xl);
}

.add-form {
  max-width: 600px;
  margin: 0 auto var(--space-2xl);
}

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

.form-group label {
  display: block;
  margin-bottom: var(--space-sm);
  font-weight: 600;
  font-size: 0.9rem;
}

.required {
  color: var(--accent-danger);
}

.form-input {
  width: 100%;
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-ja);
  font-size: 1rem;
  transition: border-color var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb),0.1);
}

.form-input::placeholder {
  color: var(--text-muted);
}

.category-input-group {
  display: flex;
  gap: var(--space-sm);
}

.category-input-group .form-input {
  flex: 1;
}

.form-textarea {
  width: 100%;
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-en);
  font-size: 0.85rem;
  resize: vertical;
  transition: border-color var(--transition-fast);
  line-height: 1.5;
}

.form-textarea:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.form-actions {
  display: flex;
  gap: var(--space-md);
}

.bulk-import-section {
  max-width: 600px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.bulk-import-section h3 {
  margin-bottom: var(--space-sm);
}

.bulk-import-section p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.bulk-import-section .btn-primary {
  margin-top: var(--space-md);
}

/* ========================================
   Buttons
   ======================================== */

.btn-primary {
  padding: var(--space-md) var(--space-xl);
  background: var(--gradient-primary);
  color: var(--on-accent);
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-ja);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn-primary::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: rgba(255,255,255,0.2);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: width 0.5s, height 0.5s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover::after {
  width: 300px;
  height: 300px;
}

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

.btn-outline {
  padding: var(--space-md) var(--space-xl);
  background: transparent;
  color: var(--accent-primary);
  border: 1px solid var(--accent-primary);
  border-radius: var(--radius-md);
  font-family: var(--font-ja);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.btn-outline:hover {
  background: rgba(var(--accent-rgb),0.1);
}

.btn-small {
  padding: var(--space-xs) var(--space-md);
  font-size: 0.8rem;
}

.btn-large {
  padding: var(--space-md) var(--space-2xl);
  font-size: 1.1rem;
}

.btn-icon {
  margin-left: var(--space-sm);
}

/* ========================================
   Toast Notifications
   ======================================== */

.toast-container {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.toast {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  animation: slideInRight 0.4s ease, fadeOut 0.4s ease 2.6s forwards;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  box-shadow: var(--shadow-lg);
  max-width: 350px;
}

.toast-success {
  background: linear-gradient(135deg, rgba(var(--success-rgb),0.9), rgba(var(--success2-rgb),0.9));
  color: #0b0e17;
}

.toast-error {
  background: linear-gradient(135deg, rgba(var(--danger-rgb),0.9), rgba(var(--warning-rgb),0.9));
  color: #0b0e17;
}

.toast-info {
  background: linear-gradient(135deg, rgba(var(--accent-rgb),0.9), rgba(var(--secondary-rgb),0.9));
  color: var(--on-accent);
}

/* ========================================
   Animations
   ======================================== */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes bearBounce {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  25% { transform: translateY(-10px) rotate(-3deg); }
  75% { transform: translateY(-5px) rotate(3deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(200%); }
}

@keyframes slideInRight {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

@keyframes fadeOut {
  from { opacity: 1; }
  to { opacity: 0; }
}

@keyframes correctPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

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

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
  #app {
    padding: 0 var(--space-md);
    padding-bottom: 68px; /* space for bottom tab bar */
  }

  /* --- Top bar: compact, single row --- */
  #main-nav {
    flex-wrap: nowrap;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    padding-top: calc(env(safe-area-inset-top, 0px) + var(--space-sm));
    margin-bottom: var(--space-md);
  }

  .nav-brand {
    gap: var(--space-xs);
  }

  .brand-icon {
    font-size: 1.4rem;
  }

  .brand-text {
    font-size: 1rem;
  }

  .nav-streak {
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.8rem;
  }

  .streak-flame {
    font-size: 1rem;
  }

  .nav-user {
    padding: 4px 8px;
  }

  .user-avatar {
    width: 24px;
    height: 24px;
  }

  .nav-logout-btn {
    font-size: 11px;
    padding: 2px 6px;
  }

  /* --- Bottom tab bar --- */
  .nav-links {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 200;
    background: var(--nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--border-subtle);
    display: flex;
    justify-content: space-around;
    padding: var(--space-xs) 0;
    padding-bottom: env(safe-area-inset-bottom, var(--space-xs));
    width: 100%;
    order: unset;
    overflow-x: visible;
  }

  .nav-btn {
    padding: 4px 0;
    min-width: 0;
    flex: 1;
  }

  .nav-icon {
    font-size: 1.3rem;
  }

  .nav-label {
    display: block;
    font-size: 0.6rem;
    line-height: 1;
  }

  /* --- Page headers: compact --- */
  .study-header,
  .quiz-header,
  .wordlist-header,
  .add-header,
  .stats-header {
    margin-bottom: var(--space-md);
  }

  .study-header h2,
  .quiz-header h2,
  .wordlist-header h2,
  .add-header h2 {
    font-size: 1.2rem;
  }

  .quiz-subtitle {
    font-size: 0.8rem;
  }

  /* --- Dashboard compact --- */
  .dashboard-hero {
    flex-direction: column;
    text-align: center;
    padding: var(--space-md);
    margin-bottom: var(--space-md);
    gap: var(--space-md);
  }

  .hero-greeting {
    font-size: 1.3rem;
  }

  .bear-animation {
    font-size: 2.5rem;
  }

  .hero-speech-bubble {
    font-size: 0.85rem;
    padding: var(--space-sm) var(--space-md);
  }

  .dashboard-cards {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
  }

  .dash-card {
    padding: var(--space-md);
  }

  .card-number {
    font-size: 1.6rem;
  }

  .card-label {
    font-size: 0.7rem;
  }

  .science-tip {
    margin-bottom: var(--space-md);
    padding: var(--space-md);
  }

  .tip-content {
    font-size: 0.8rem;
  }

  .today-progress {
    margin-bottom: var(--space-md);
  }

  .today-progress h3 {
    font-size: 1rem;
  }

  .level-display {
    margin-bottom: var(--space-md);
  }

  /* --- Study/Quiz compact --- */
  .flashcard-word {
    font-size: 2rem;
  }

  .srs-btn {
    padding: var(--space-xs);
    gap: 2px;
  }

  .quiz-options {
    grid-template-columns: 1fr;
  }

  .quiz-question {
    font-size: 1.8rem;
  }

  .quiz-modes {
    gap: var(--space-sm) !important;
  }

  .quiz-mode-card h3 {
    font-size: 1rem;
  }

  .quiz-mode-card p {
    font-size: 0.75rem;
  }

  /* --- Other compact --- */
  .wordlist-controls {
    flex-direction: column;
  }

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

  .stats-overview {
    grid-template-columns: repeat(2, 1fr);
  }

  .form-actions {
    flex-direction: column;
  }

  .results-actions {
    flex-direction: column;
    align-items: center;
  }

  .settings-container {
    gap: var(--space-md);
  }

  .settings-section {
    padding: var(--space-lg);
  }

  .settings-section h3 {
    font-size: 1rem;
  }

  .language-radio-group {
    grid-template-columns: 1fr;
  }

  .language-radio {
    padding: var(--space-sm) var(--space-md);
  }

  .radio-label {
    font-size: 0.85rem;
  }

  .apikey-input-group {
    flex-direction: column;
    align-items: stretch;
  }

  .apikey-input {
    min-width: 0;
    max-width: 100%;
  }

  .apikey-masked {
    font-size: 0.8rem;
    word-break: break-all;
  }

  .apikey-guide {
    padding: var(--space-sm) var(--space-md);
  }

  .apikey-guide ol {
    padding-left: 1.2em;
    font-size: 0.8rem;
  }

  .voice-select-grid {
    grid-template-columns: 1fr;
  }

  .tts-slider {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .dashboard-cards {
    grid-template-columns: 1fr;
  }

  .nav-label {
    display: none;
  }

  .nav-icon {
    font-size: 1.4rem;
  }

  .settings-section {
    padding: var(--space-md);
  }

  .settings-desc {
    font-size: 0.8rem;
    margin-bottom: var(--space-md);
  }

  .daily-goal-input {
    flex-wrap: wrap;
  }

  .form-select {
    font-size: 0.8rem;
    padding: 6px 10px;
  }

  .btn-sm {
    padding: 5px 12px;
    font-size: 0.8rem;
    width: 100%;
  }
}

/* ========================================
   Confirm Dialog Overlay
   ======================================== */

.confirm-dialog-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  animation: fadeIn 0.2s ease;
}

.confirm-dialog-overlay .confirm-dialog {
  background: var(--bg-card);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  max-width: 400px;
  width: 90%;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.confirm-dialog-overlay .confirm-dialog h3 {
  margin-bottom: var(--space-md);
  font-size: 1.1rem;
}

.confirm-dialog-overlay .confirm-dialog p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: var(--space-xl);
}

.confirm-dialog-overlay .confirm-dialog .confirm-actions {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
}

/* ========================================
   Image Overlay (Lightbox)
   ======================================== */

.image-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  cursor: pointer;
  animation: fadeIn 0.2s ease;
}

.image-overlay-img {
  width: 80vw;
  max-height: 80vh;
  object-fit: contain;
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  cursor: pointer;
  animation: zoomIn 0.25s ease;
}

@keyframes zoomIn {
  from { transform: scale(0.7); opacity: 0; }
  to   { transform: scale(1);   opacity: 1; }
}

/* ========================================
   Blazor Error UI
   ======================================== */

#blazor-error-ui {
  background: linear-gradient(135deg, rgba(var(--danger-rgb),0.95), rgba(220,38,38,0.95));
  color: white;
  font-family: var(--font-ja);
  font-size: 0.9rem;
  padding: var(--space-md) var(--space-xl);
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 9999;
  text-align: center;
  display: none;
  box-shadow: 0 -4px 16px rgba(0,0,0,0.4);
}

#blazor-error-ui .dismiss {
  cursor: pointer;
  position: absolute;
  right: var(--space-lg);
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.2);
  border: none;
  color: white;
  border-radius: var(--radius-sm);
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.8rem;
}

#blazor-error-ui .dismiss:hover {
  background: rgba(255,255,255,0.3);
}

/* ========================================
   Toast Animation (Blazor component)
   ======================================== */

.toast-container .toast {
  animation: slideInRight 0.4s ease;
}

/* ========================================
   Login Page
   ======================================== */

.login-page {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: calc(100dvh - 120px);
  background: var(--bg-primary);
  padding: 20px;
}

.login-card {
  background: var(--bg-card);
  border-radius: 24px;
  padding: 48px 40px;
  text-align: center;
  max-width: 400px;
  width: 100%;
  border: 1px solid rgba(255,255,255,0.06);
}

.login-bear {
  font-size: 64px;
  margin-bottom: 16px;
}

.login-card h1 {
  font-family: 'M PLUS Rounded 1c', sans-serif;
  font-size: 28px;
  font-weight: 800;
  color: var(--text-primary);
  margin: 0 0 8px;
}

.login-card p {
  color: var(--text-secondary);
  margin: 0 0 8px;
}

.login-subtitle {
  font-size: 14px;
  color: var(--text-muted) !important;
  margin-bottom: 32px !important;
}

.btn-google-login {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 28px;
  background: #fff;
  color: #333;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  margin-top: 16px;
}

.btn-google-login:hover {
  background: #f1f1f1;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
}

/* ========================================
   Nav User Section
   ======================================== */

.nav-user {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
}

.user-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
}

.nav-logout-btn {
  font-size: 12px;
  color: var(--text-muted);
  text-decoration: none;
  padding: 4px 8px;
  border-radius: 6px;
  transition: all 0.2s;
}

.nav-logout-btn:hover {
  color: var(--accent-danger);
  background: rgba(var(--danger-rgb), 0.1);
}

.nav-user {
  position: relative;
}

.nav-user-trigger {
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  border-radius: 50%;
}

.user-avatar-fallback {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-primary);
  color: var(--on-accent);
  font-size: 13px;
  font-weight: 700;
}

.nav-user-backdrop {
  position: fixed;
  inset: 0;
  z-index: 900;
}

.nav-user-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 901;
  min-width: 200px;
  background: var(--bg-card, #1e293b);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.35);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.nav-user-info {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border-subtle);
}

.nav-user-name {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.nav-user-email {
  font-size: 0.75rem;
  color: var(--text-muted);
  word-break: break-all;
}

.nav-user-logout {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary, var(--text-muted));
  transition: all 0.2s;
}

.nav-user-logout:hover {
  color: var(--accent-danger);
  background: rgba(var(--danger-rgb), 0.1);
}

/* ========================================
   Settings Page
   ======================================== */

.settings-container {
  max-width: 600px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.settings-section {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.settings-section h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 var(--space-xs);
}

.settings-desc {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin: 0 0 var(--space-lg);
}

/* Toggle row + switch (e.g. AI Conversation auto-translate) */
.setting-toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-subtle);
}

.setting-toggle-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.setting-toggle-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.setting-toggle-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.setting-switch {
  position: relative;
  display: inline-block;
  flex: 0 0 auto;
  width: 48px;
  height: 26px;
}

.setting-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.setting-switch-slider {
  position: absolute;
  inset: 0;
  cursor: pointer;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  transition: background 0.2s, border-color 0.2s;
}

.setting-switch-slider::before {
  content: "";
  position: absolute;
  height: 18px;
  width: 18px;
  left: 3px;
  top: 50%;
  transform: translateY(-50%);
  background: var(--text-secondary);
  border-radius: 50%;
  transition: transform 0.2s, background 0.2s;
}

.setting-switch input:checked + .setting-switch-slider {
  background: rgba(var(--accent-rgb), 0.25);
  border-color: var(--accent-primary);
}

.setting-switch input:checked + .setting-switch-slider::before {
  transform: translate(22px, -50%);
  background: var(--accent-primary);
}

.setting-switch input:focus-visible + .setting-switch-slider {
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.25);
}

.language-radio-group {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
}

.language-radio {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
}

.language-radio input[type="radio"] {
  flex-shrink: 0;
  accent-color: var(--accent-primary);
}

.language-radio:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.language-radio.selected {
  border-color: var(--accent-primary);
  background: rgba(var(--accent-rgb), 0.08);
}

.radio-label {
  font-size: 0.9rem;
  color: var(--text-primary);
  line-height: 1.3;
}

.radio-desc-warn {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.language-checkbox-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.language-checkbox {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
}

.language-checkbox:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.language-checkbox.selected {
  border-color: var(--accent-primary);
  background: rgba(var(--accent-rgb), 0.08);
}

.language-checkbox input[type="checkbox"] {
  accent-color: var(--accent-primary);
  width: 18px;
  height: 18px;
}

.checkbox-label {
  font-size: 0.95rem;
  color: var(--text-primary);
}

.daily-goal-input {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.goal-unit {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.tts-slider-group {
  margin-bottom: var(--space-md);
}
.tts-slider-label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}
.tts-slider {
  width: 100%;
  max-width: 300px;
  accent-color: var(--accent-primary);
}
.voice-select-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}
.voice-select-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.voice-select-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}
.form-select {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--bg-tertiary);
  border-radius: var(--radius-md);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.85rem;
  cursor: pointer;
  appearance: auto;
}
.form-select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px rgba(var(--accent-primary-rgb, 99, 102, 241), 0.2);
}
.apikey-input-group {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-bottom: var(--space-xs);
}
.apikey-input {
  flex: 1;
  min-width: 200px;
  max-width: 400px;
  font-family: monospace;
  font-size: 0.85rem;
}
.apikey-masked {
  font-family: monospace;
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: 6px 12px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
}
.apikey-status.valid {
  color: var(--accent-success, #22c55e);
  font-size: 0.85rem;
  font-weight: 600;
}
.apikey-guide {
  background: var(--bg-secondary);
  border: 1px solid var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin: var(--space-sm) 0 var(--space-md);
}
.apikey-guide h4 {
  margin: 0 0 var(--space-sm);
  font-size: 0.9rem;
  color: var(--text-primary);
}
.apikey-guide ol {
  margin: 0;
  padding-left: 1.5em;
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.apikey-guide li {
  margin-bottom: 6px;
}
.apikey-guide a {
  color: var(--accent-primary);
  text-decoration: underline;
}
.settings-error {
  color: var(--accent-danger, #ef4444);
  font-size: 0.85rem;
  margin: var(--space-xs) 0;
}
.settings-hint {
  font-size: 0.8rem;
  color: var(--text-tertiary);
  margin: var(--space-xs) 0 var(--space-md);
}
.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}
.language-radio.disabled {
  opacity: 0.5;
  pointer-events: none;
}

.settings-actions {
  display: flex;
  justify-content: center;
  padding-bottom: var(--space-xl);
}

/* ========================================
   Word Tags (Chips)
   ======================================== */

.word-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 4px;
}

.word-tag {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.word-tag.tag-pos {
  background: rgba(var(--accent-rgb), 0.15);
  color: var(--accent-primary);
  border: 1px solid rgba(var(--accent-rgb), 0.25);
}

.word-tag.tag-cat {
  background: rgba(var(--tertiary-rgb), 0.15);
  color: var(--science-text);
  border: 1px solid rgba(var(--tertiary-rgb), 0.25);
}

/* Clicking a tag chip filters the Word List by that tag */
.word-tag--filter {
  cursor: pointer;
  transition: filter 0.15s, box-shadow 0.15s;
}

.word-tag--filter:hover {
  filter: brightness(1.25);
}

.word-tag--filter.is-active {
  box-shadow: 0 0 0 2px currentColor;
}

.word-tag-remove {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  font-size: 0.85rem;
  line-height: 1;
  margin-left: 4px;
  padding: 0;
  opacity: 0.6;
}

.word-tag-remove:hover {
  opacity: 1;
}

.word-tag-add {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.7rem;
  font-weight: 600;
  background: transparent;
  color: var(--text-muted);
  border: 1px dashed var(--border-subtle);
  cursor: pointer;
  transition: all 0.2s;
}

.word-tag-add:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.word-tag-input {
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: 10px;
  border: 1px solid var(--accent-primary);
  background: var(--bg-elevated, rgba(255,255,255,0.05));
  color: var(--text-primary);
  max-width: 140px;
}

/* Personal tag management (Settings) */
.personal-tag-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: var(--space-sm);
}

.personal-tag-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* ===== Flashcard tags (Study screen) ===== */
.flashcard-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-top: var(--space-md);
}

.fc-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 11px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.4;
}

.fc-tag-sys {
  background: rgba(var(--accent-rgb), 0.12);
  color: var(--accent-primary);
  border: 1px solid rgba(var(--accent-rgb), 0.28);
}

.fc-tag-user {
  background: rgba(var(--tertiary-rgb), 0.15);
  color: var(--science-text);
  border: 1px solid rgba(var(--tertiary-rgb), 0.3);
}

.fc-tag-author {
  background: rgba(var(--success-rgb), 0.13);
  color: var(--accent-success);
  border: 1px solid rgba(var(--success-rgb), 0.28);
}

.fc-tag-remove {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1;
  padding: 0;
  margin-left: 1px;
  opacity: 0.55;
  transition: opacity 0.15s;
}
.fc-tag-remove:hover { opacity: 1; }

.fc-tag-add {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 3px 12px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
  background: transparent;
  color: var(--text-muted);
  border: 1px dashed var(--border-accent);
  cursor: pointer;
  transition: all 0.2s;
}
.fc-tag-add:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background: rgba(var(--accent-rgb), 0.08);
}

/* Add/select editor panel */
.fc-tag-editor {
  margin: var(--space-sm) auto 0;
  max-width: 360px;
  width: 100%;
  background: var(--bg-elevated);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
  padding: var(--space-sm) var(--space-md);
  box-shadow: var(--shadow-md);
  animation: fc-tag-pop 0.18s ease-out;
}
@keyframes fc-tag-pop {
  from { opacity: 0; transform: translateY(-6px) scale(0.98); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.fc-tag-input-row {
  display: flex;
  align-items: center;
  gap: 6px;
}
.fc-tag-input-icon { font-size: 0.95rem; opacity: 0.85; }

.fc-tag-input {
  flex: 1;
  min-width: 0;
  font-size: 0.85rem;
  padding: 6px 10px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-accent);
  background: var(--bg-primary);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.fc-tag-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.18);
}

.fc-tag-confirm,
.fc-tag-cancel {
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: filter 0.15s, background 0.15s, color 0.15s, opacity 0.15s;
}
.fc-tag-confirm {
  background: var(--accent-primary);
  color: #06131f;
}
.fc-tag-confirm:disabled { opacity: 0.4; cursor: default; }
.fc-tag-confirm:not(:disabled):hover { filter: brightness(1.1); }
.fc-tag-cancel {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
}
.fc-tag-cancel:hover { background: rgba(var(--danger-rgb), 0.18); color: var(--accent-danger); }

.fc-tag-suggestions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 5px;
  margin-top: var(--space-sm);
  padding-top: var(--space-sm);
  border-top: 1px dashed var(--border-subtle);
}
.fc-tag-suggestions-label {
  font-size: 0.68rem;
  color: var(--text-muted);
  margin-right: 2px;
}
.fc-tag-suggestion {
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
  background: rgba(var(--tertiary-rgb), 0.1);
  color: var(--science-text);
  border: 1px solid rgba(var(--tertiary-rgb), 0.25);
  cursor: pointer;
  transition: all 0.15s;
}
.fc-tag-suggestion:hover {
  background: rgba(var(--tertiary-rgb), 0.22);
  border-color: var(--science-text);
}

/* ========================================
   Admin Page
   ======================================== */

.admin-header {
  text-align: center;
  padding: 1.5rem 0 1rem;
}

.admin-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.admin-denied {
  text-align: center;
  padding: 4rem 2rem;
}

.admin-denied .denied-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.admin-denied h3 {
  color: var(--accent-danger);
  margin-bottom: 0.5rem;
}

.admin-denied p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.admin-section {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.admin-section h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.admin-section p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.admin-btn-group {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.admin-progress {
  margin-top: 1rem;
}

.admin-progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 0.5rem;
}

.admin-progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 4px;
  transition: width 0.3s ease;
}

.admin-progress-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.admin-file-upload {
  border: 2px dashed var(--border-accent);
  border-radius: 12px;
  padding: 2rem;
  text-align: center;
  transition: border-color 0.2s;
}

.admin-file-upload:hover {
  border-color: var(--border-hover);
}

.admin-file-upload ::deep input[type="file"] {
  color: var(--text-secondary);
}

.admin-import-result {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: rgba(var(--success-rgb), 0.1);
  border: 1px solid rgba(var(--success-rgb), 0.3);
  border-radius: 8px;
  color: var(--accent-success);
  font-size: 0.9rem;
}

.admin-confirm {
  padding: 1rem;
  background: rgba(var(--warning-rgb), 0.08);
  border: 1px solid rgba(var(--warning-rgb), 0.3);
  border-radius: 10px;
}

.admin-confirm-text {
  margin: 0 0 1rem;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.admin-confirm-actions {
  display: flex;
  gap: var(--space-sm);
}

.admin-matrix-wrap {
  overflow-x: auto;
}

.admin-matrix {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.admin-matrix th,
.admin-matrix td {
  padding: 0.6rem 0.8rem;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}

.admin-matrix th {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.admin-matrix td:last-child {
  text-align: right;
}

.lang-code {
  display: inline-block;
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-primary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-right: 0.5rem;
}

.lang-name {
  color: var(--text-primary);
}

.badge-missing {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
}

.badge-complete {
  background: rgba(var(--success-rgb), 0.15);
  color: var(--accent-success);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
}

.coverage-bar {
  display: inline-block;
  width: 60px;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  overflow: hidden;
  vertical-align: middle;
  margin-right: 0.4rem;
}

.coverage-fill {
  height: 100%;
  background: var(--accent-primary);
  border-radius: 3px;
  transition: width 0.3s ease;
}

.coverage-fill.complete {
  background: var(--accent-success);
}

.coverage-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.source-row {
  opacity: 0.6;
}

.badge-source {
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-primary);
  padding: 2px 6px;
  border-radius: 10px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-left: 0.4rem;
}

.text-muted {
  color: var(--text-secondary);
  opacity: 0.5;
}

/* ── Help Page ─────────────────────────────────────────── */
.help-page {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 1rem 3rem;
}

.help-header {
  padding: 1.5rem 0 0.5rem;
}

.help-header h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 0;
}

.help-section {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.4rem 1.6rem;
  margin-top: 1.2rem;
}

.help-section h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin: 0 0 0.9rem;
}

.help-desc {
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

/* Feature list */
.help-feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.help-feature-list li {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
}

.help-feature-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.help-feature-list li > div strong {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.help-feature-list li > div p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Screen guide grid */
.help-screen-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.8rem;
}

.help-screen-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 0.9rem 1rem;
}

.help-screen-icon {
  font-size: 1.3rem;
  display: block;
  margin-bottom: 0.35rem;
}

.help-screen-card strong {
  display: block;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
}

.help-screen-card p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* Changelog */
.help-changelog {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.changelog-entry {
  display: grid;
  grid-template-columns: 70px 100px 1fr;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--border-color);
}

.changelog-entry:last-child {
  border-bottom: none;
}

.changelog-version {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  background: color-mix(in srgb, var(--accent-primary) 12%, transparent);
  padding: 2px 7px;
  border-radius: 8px;
  text-align: center;
}

.changelog-date {
  font-size: 0.8rem;
  color: var(--text-muted, var(--text-secondary));
  opacity: 0.7;
}

.changelog-entry p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== AI Chat — Unified Conversation Timeline (Glass + Neon Dark) ===== */
.aichat-shell {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  padding-bottom: 3rem;
}

/* ---- Top bar (glass header) ---- */
.aichat-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}
.aichat-brand { display: flex; align-items: center; gap: 0.85rem; min-width: 0; }
.aichat-brand-glyph {
  font-size: 1.6rem;
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: var(--radius-md);
  background: var(--gradient-card);
  border: 1px solid var(--border-accent);
  box-shadow: var(--shadow-glow);
  filter: drop-shadow(0 0 8px rgba(var(--accent-rgb), 0.4));
}
.aichat-brand-title {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.aichat-counter {
  display: flex; flex-direction: column; align-items: center;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  flex: 0 0 auto;
}
.aichat-counter-num { font-size: 1.3rem; font-weight: 800; color: var(--accent-primary); line-height: 1; }
.aichat-counter-lbl { font-size: 0.64rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); }

/* ---- Key-missing card ---- */
.aichat-keycard {
  text-align: center;
  border-radius: var(--radius-lg);
  padding: 2.5rem 1.5rem;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);
}
.aichat-keycard-icon { font-size: 2.6rem; margin-bottom: 0.4rem; }
.aichat-keycard-title { margin: 0.4rem 0 0.4rem; color: var(--text-primary); font-weight: 700; }
.aichat-keycard-desc { margin: 0 auto 1.25rem; max-width: 420px; color: var(--text-secondary); font-size: 0.92rem; line-height: 1.5; }

/* ===== Work area (compose, on top) ===== */
.aichat-workarea {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.25rem;
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-accent);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.aichat-workarea-glow {
  position: absolute; inset: 0;
  background: var(--gradient-glow);
  pointer-events: none;
}
.aichat-workarea > .aichat-bubble,
.aichat-workarea > .aichat-flow { position: relative; z-index: 1; }

/* Conversation bubbles */
.aichat-bubble {
  position: relative;
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.aichat-bubble--source:focus-within {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}
.aichat-bubble-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.6rem;
}
.aichat-bubble-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-primary);
}
.aichat-dot {
  width: 8px; height: 8px;
  border-radius: var(--radius-full);
  box-shadow: 0 0 8px currentColor;
}
.aichat-dot--source { background: var(--accent-primary); color: var(--accent-primary); }
.aichat-dot--target { background: var(--accent-tertiary); color: var(--science-text); }
.aichat-langtag {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 0.12rem 0.5rem;
  border-radius: var(--radius-full);
  background: rgba(var(--accent-rgb), 0.12);
  color: var(--accent-primary);
  border: 1px solid var(--border-accent);
}
.aichat-langtag--alt {
  color: var(--science-text);
  background: rgba(var(--tertiary-rgb), 0.12);
  border-color: rgba(var(--tertiary-rgb), 0.3);
}
.aichat-bubble-actions { display: flex; gap: 0.5rem; flex-wrap: wrap; }

.aichat-textarea {
  width: 100%;
  min-height: 96px;
  resize: vertical;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.85rem;
  font-size: 1rem;
  font-family: inherit;
  line-height: 1.55;
  background: rgba(11, 14, 23, 0.6);
  color: var(--text-primary);
  box-sizing: border-box;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.aichat-textarea::placeholder { color: var(--text-muted); }
/* Washi & Matcha: dark-tinted textarea bg needs a white placeholder for contrast */
[data-skin="washi"] .aichat-textarea::placeholder { color: #fff; }
.aichat-textarea:focus {
  outline: none;
  border-color: var(--border-hover);
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.12);
}
.aichat-branch-note {
  margin-top: 0.55rem;
  font-size: 0.78rem;
  color: var(--accent-success);
  background: rgba(var(--success-rgb), 0.1);
  border: 1px solid rgba(var(--success-rgb), 0.25);
  border-radius: var(--radius-sm);
  padding: 0.35rem 0.6rem;
}
.aichat-translation-box {
  min-height: 60px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.85rem;
  font-size: 1rem;
  line-height: 1.55;
  background: rgba(var(--tertiary-rgb), 0.06);
  color: var(--text-primary);
  white-space: pre-wrap;
}

/* Mic recording pulse */
.aichat-mic.recording {
  background: var(--accent-danger) !important;
  box-shadow: 0 0 0 0 rgba(var(--danger-rgb), 0.5);
  animation: aichat-pulse 1.4s ease-in-out infinite;
}
@keyframes aichat-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(var(--danger-rgb), 0.5); }
  70%  { box-shadow: 0 0 0 10px rgba(var(--danger-rgb), 0); }
  100% { box-shadow: 0 0 0 0 rgba(var(--danger-rgb), 0); }
}

/* Translate flow */
.aichat-flow {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 0.35rem 0;
}
.aichat-flow-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-accent), transparent);
}
.aichat-translate-btn {
  flex: 0 0 auto;
  border: none;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--on-accent);
  padding: 0.55rem 1.15rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary) 55%, var(--accent-tertiary));
  box-shadow: var(--shadow-md), var(--shadow-glow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
}
.aichat-translate-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg), var(--shadow-glow-strong);
}
.aichat-translate-btn:disabled { opacity: 0.45; cursor: not-allowed; }

.aichat-status { font-size: 0.85rem; color: var(--accent-primary); margin: 0.5rem 0 0; }
.aichat-empty { color: var(--text-muted); font-size: 0.9rem; }

/* ===== History (tree, below work area) ===== */
.aichat-history-head { margin-bottom: 0.85rem; }
.aichat-history-title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}
.aichat-history-empty {
  text-align: center;
  padding: 2.25rem 1rem;
  background: var(--bg-card);
  border: 1px dashed var(--border-subtle);
  border-radius: var(--radius-lg);
}
.aichat-history-empty-glyph { font-size: 2rem; display: block; margin-bottom: 0.5rem; opacity: 0.6; }

/* ===== Tree ===== */
.aichat-tree { display: flex; flex-direction: column; gap: 0.6rem; }
.aichat-node-wrap { position: relative; }

/* children indented under their parent, with a vertical connector rail */
.aichat-children {
  position: relative;
  margin-left: 1.35rem;
  padding-left: 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-top: 0.6rem;
}
.aichat-children::before {
  content: "";
  position: absolute;
  left: 0; top: -0.3rem; bottom: 0.9rem;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-secondary), rgba(var(--secondary-rgb), 0.15));
  border-radius: var(--radius-full);
}

/* node card */
.aichat-node {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  padding: 0.7rem 0.85rem 0.7rem 1.15rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: background var(--transition-fast), border-color var(--transition-fast),
              transform var(--transition-spring), box-shadow var(--transition-fast);
}
.aichat-node:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateX(2px);
}
.aichat-node.active {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-glow);
  background: var(--bg-elevated);
}

/* elbow connector from rail to child node */
.aichat-children > .aichat-node-wrap > .aichat-node .aichat-node-rail {
  position: absolute;
  left: -1.1rem; top: 1.4rem;
  width: 1.1rem; height: 2px;
  background: var(--accent-secondary);
  opacity: 0.7;
}
.aichat-tree > .aichat-node-wrap > .aichat-node .aichat-node-rail { display: none; }

/* node dot (depth-tinted) */
.aichat-node-dot {
  position: absolute;
  left: -0.36rem; top: 1.05rem;
  width: 11px; height: 11px;
  border-radius: var(--radius-full);
  background: var(--accent-primary);
  border: 2px solid var(--bg-primary);
  box-shadow: 0 0 8px rgba(var(--accent-rgb), 0.6);
}
.aichat-node.is-child .aichat-node-dot {
  background: var(--accent-secondary);
  box-shadow: 0 0 8px rgba(var(--secondary-rgb), 0.6);
}
.aichat-depth-2 > .aichat-node .aichat-node-dot,
.aichat-depth-3 > .aichat-node .aichat-node-dot,
.aichat-depth-4 > .aichat-node .aichat-node-dot,
.aichat-depth-5 > .aichat-node .aichat-node-dot {
  background: var(--accent-tertiary);
  box-shadow: 0 0 8px rgba(var(--tertiary-rgb), 0.6);
}

.aichat-node-body { flex: 1; min-width: 0; cursor: pointer; }
.aichat-node-meta {
  display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap;
  margin-bottom: 0.3rem;
}
.aichat-node-badge {
  font-size: 0.64rem; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase;
  padding: 0.1rem 0.5rem; border-radius: var(--radius-full);
}
.aichat-node-badge.root {
  color: var(--accent-primary);
  background: rgba(var(--accent-rgb), 0.12);
  border: 1px solid var(--border-accent);
}
.aichat-node-badge.branch {
  color: var(--science-text);
  background: rgba(var(--tertiary-rgb), 0.12);
  border: 1px solid rgba(var(--tertiary-rgb), 0.3);
}
.aichat-node-time { font-size: 0.72rem; color: var(--text-muted); font-variant-numeric: tabular-nums; }
.aichat-node-source { font-size: 0.92rem; color: var(--text-primary); line-height: 1.45; word-break: break-word; }
.aichat-node-trans {
  font-size: 0.85rem; color: var(--text-secondary); line-height: 1.45; margin-top: 0.25rem;
  padding-top: 0.3rem; border-top: 1px dashed var(--border-subtle); word-break: break-word;
}

.aichat-node-actions { display: flex; flex-direction: column; gap: 0.35rem; flex: 0 0 auto; }
.aichat-node-btn {
  width: 32px; height: 32px;
  display: grid; place-items: center;
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast),
              box-shadow var(--transition-fast), transform var(--transition-fast);
}
.aichat-node-btn:hover:not(:disabled) {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-1px);
}
.aichat-node-btn.branch:hover:not(:disabled) {
  border-color: rgba(var(--tertiary-rgb), 0.5);
  box-shadow: 0 0 10px rgba(var(--tertiary-rgb), 0.3);
}
.aichat-node-btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* responsive */
@media (max-width: 640px) {
  .aichat-workarea { padding: 1rem; border-radius: var(--radius-md); }
  .aichat-translate-btn { font-size: 0.82rem; padding: 0.5rem 0.9rem; }
  .aichat-node { flex-wrap: wrap; }
  .aichat-node-actions { flex-direction: row; width: 100%; margin-top: 0.4rem; }
  .aichat-children { margin-left: 0.85rem; padding-left: 0.85rem; }
}

/* ===== AI Chat — 改修追加（日付グループ / ノード行 / ノード翻訳 / 折りたたみ） ===== */
.aichat-daygroup { margin-bottom: 0.75rem; }
.aichat-day-header {
  display: flex; align-items: center; gap: 0.6rem; width: 100%;
  padding: 0.5rem 0.8rem; background: var(--bg-elevated); color: var(--text-primary);
  border: 1px solid var(--border-subtle); border-radius: var(--radius-md);
  cursor: pointer; font-size: 0.9rem; transition: background 0.15s, border-color 0.15s;
}
.aichat-day-header:hover { background: var(--bg-card-hover); border-color: var(--border-accent); }
.aichat-day-header.open { border-color: var(--border-accent); }
.aichat-day-caret { color: var(--accent-primary); font-size: 0.8rem; width: 1rem; text-align: center; }
.aichat-day-date { font-weight: 600; }
.aichat-day-count {
  margin-left: auto; background: var(--bg-card); color: var(--text-secondary);
  padding: 0.1rem 0.55rem; border-radius: var(--radius-full); font-size: 0.78rem;
}
.aichat-day-today {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  color: #051018; padding: 0.1rem 0.6rem; border-radius: var(--radius-full);
  font-size: 0.72rem; font-weight: 700;
}
.aichat-daygroup .aichat-tree { margin-top: 0.5rem; }

.aichat-node-line { display: flex; align-items: flex-start; gap: 0.4rem; }
.aichat-node-line .aichat-node-source,
.aichat-node-line .aichat-node-trans { flex: 1; }
.aichat-node-translate {
  margin-top: 0.4rem; align-self: flex-start;
  background: rgba(var(--accent-rgb), 0.12); color: var(--accent-primary);
  border: 1px solid var(--border-accent); border-radius: var(--radius-sm);
  padding: 0.25rem 0.7rem; font-size: 0.8rem; cursor: pointer; transition: background 0.15s;
}
.aichat-node-translate:hover:not(:disabled) { background: rgba(var(--accent-rgb), 0.2); }
.aichat-node-translate:disabled { opacity: 0.5; cursor: default; }
.aichat-node-btn.toggle { color: var(--accent-secondary); }
.aichat-collapsed-hint {
  margin: 0.3rem 0 0.3rem 1.2rem; padding: 0.2rem 0.7rem;
  background: var(--bg-elevated); color: var(--text-secondary);
  border: 1px dashed var(--border-accent); border-radius: var(--radius-full);
  font-size: 0.76rem; cursor: pointer; transition: color 0.15s, border-color 0.15s;
}
.aichat-collapsed-hint:hover { color: var(--accent-primary); border-color: var(--border-hover); }

/* ========================================
   Skins (color themes) — applied via [data-skin] on <html>.
   "original" = the default Arctic theme defined in :root above.
   Each skin re-tints the whole UI by overriding the brand-hue RGB triplets
   plus the solid / gradient / border / shadow tokens. Every text/UI pair was
   verified to meet WCAG 2.1 AA contrast.
   ======================================== */

/* Washi & Matcha — 和紙と抹茶: warm paper light, matcha-green ink, persimmon accent */
[data-skin="washi"] {
  --accent-rgb: 91, 117, 83;
  --secondary-rgb: 154, 90, 59;
  --tertiary-rgb: 176, 138, 74;
  --success-rgb: 91, 140, 90;
  --success2-rgb: 95, 160, 140;
  --warning-rgb: 203, 138, 43;
  --danger-rgb: 196, 74, 63;

  --bg-primary: #f7f3ea;
  --bg-secondary: #f1ebdd;
  --bg-card: #fffdf7;
  --bg-card-hover: #fbf6ec;
  --bg-elevated: #fffefb;
  --bg-glass: rgba(255, 253, 247, 0.82);

  --text-primary: #2b2620;
  --text-secondary: #6b6358;
  --text-muted: #83796b;
  --text-accent: #9a5a3b;

  --accent-primary: #5b7553;
  --accent-primary-dark: #46603f;
  --accent-secondary: #9a5a3b;
  --accent-tertiary: #b08a4a;
  --accent-success: #5b8c5a;
  --accent-success-dark: #3f7d57;
  --accent-warning: #cb8a2b;
  --accent-danger: #c44a3f;
  --accent-danger-dark: #b4342b;

  --gradient-primary: linear-gradient(135deg, #5b7553 0%, #46603f 100%);
  --gradient-secondary: linear-gradient(135deg, #b07a4a 0%, #9a5a3b 100%);
  --gradient-success: linear-gradient(135deg, #5b8c5a 0%, #3f7d57 100%);
  --gradient-warm: linear-gradient(135deg, #d6a24a 0%, #b86a3c 100%);
  --gradient-hero: linear-gradient(135deg, #f7f3ea 0%, #f1ebdd 55%, #ece3d2 100%);
  --gradient-card: linear-gradient(135deg, rgba(91,117,83,0.05) 0%, rgba(154,90,59,0.04) 100%);
  --gradient-glow: radial-gradient(ellipse at 50% 0%, rgba(91,117,83,0.08) 0%, transparent 65%);

  --border-subtle: rgba(43, 38, 32, 0.10);
  --border-accent: rgba(91, 117, 83, 0.35);
  --border-hover: rgba(91, 117, 83, 0.55);

  --shadow-sm: 0 1px 2px rgba(58, 48, 34, 0.06), 0 1px 3px rgba(58, 48, 34, 0.08);
  --shadow-md: 0 2px 6px rgba(58, 48, 34, 0.07), 0 4px 12px rgba(58, 48, 34, 0.09);
  --shadow-lg: 0 6px 16px rgba(58, 48, 34, 0.10), 0 12px 32px rgba(58, 48, 34, 0.12);
  --shadow-glow: 0 2px 10px rgba(91, 117, 83, 0.14);
  --shadow-glow-strong: 0 4px 18px rgba(91, 117, 83, 0.20);

  --surface-sunken: #f1ebdd;
  --on-accent: #ffffff;
  --science-text: #834b30;
  --nav-bg: rgba(247, 243, 234, 0.85);
}

/* Candlelit Study — 灯火（ともしび）: warm espresso dark, honey amber + sage, restful at night */
[data-skin="tomoshibi"] {
  --accent-rgb: 224, 169, 103;
  --secondary-rgb: 201, 154, 106;
  --tertiary-rgb: 176, 137, 104;
  --success-rgb: 163, 177, 138;
  --success2-rgb: 138, 166, 140;
  --warning-rgb: 224, 169, 103;
  --danger-rgb: 217, 140, 122;

  --bg-primary: #1c1714;
  --bg-secondary: #241d19;
  --bg-card: #2a221d;
  --bg-card-hover: #33291f;
  --bg-elevated: #312720;
  --bg-glass: rgba(42, 34, 29, 0.82);

  --text-primary: #f3e9df;
  --text-secondary: #c5b3a3;
  --text-muted: #9a8676;
  --text-accent: #e6b87a;

  --accent-primary: #e0a967;
  --accent-primary-dark: #c98a3e;
  --accent-secondary: #c99a6a;
  --accent-tertiary: #b08968;
  --accent-success: #a3b18a;
  --accent-success-dark: #7d9468;
  --accent-warning: #e0a967;
  --accent-danger: #d98c7a;
  --accent-danger-dark: #c87557;

  --gradient-primary: linear-gradient(135deg, #e0a967 0%, #c98a3e 100%);
  --gradient-secondary: linear-gradient(135deg, #c99a6a 0%, #b08968 100%);
  --gradient-success: linear-gradient(135deg, #a3b18a 0%, #7d9468 100%);
  --gradient-warm: linear-gradient(135deg, #e0a967 0%, #d98c7a 100%);
  --gradient-hero: linear-gradient(160deg, #241d19 0%, #2a221d 55%, #1c1714 100%);
  --gradient-card: linear-gradient(135deg, rgba(224,169,103,0.07) 0%, rgba(176,137,104,0.05) 100%);
  --gradient-glow: radial-gradient(ellipse at 50% 0%, rgba(224,169,103,0.10) 0%, transparent 62%);

  --border-subtle: rgba(224, 169, 103, 0.10);
  --border-accent: rgba(224, 169, 103, 0.30);
  --border-hover: rgba(224, 169, 103, 0.46);

  --shadow-sm: 0 2px 8px rgba(10, 6, 3, 0.40);
  --shadow-md: 0 6px 18px rgba(10, 6, 3, 0.48);
  --shadow-lg: 0 14px 40px rgba(8, 5, 2, 0.55);
  --shadow-glow: 0 4px 18px rgba(201, 138, 62, 0.18);
  --shadow-glow-strong: 0 6px 26px rgba(201, 138, 62, 0.26);

  --surface-sunken: #181310;
  --on-accent: #231a12;
  --science-text: #d8b48f;
  --nav-bg: rgba(28, 23, 20, 0.85);
}

/* ========================================
   Skin selector (Settings page)
   ======================================== */
.skin-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-md);
}

.skin-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-sm);
  background: var(--bg-card);
  border: 2px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: left;
  font-family: var(--font-ja);
  position: relative;
}

.skin-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.skin-card.selected {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-glow);
}

.skin-preview {
  position: relative;
  display: block;
  height: 84px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-subtle);
}

.skin-preview-bar {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 22px;
}

.skin-preview-dots {
  position: absolute;
  top: 30px; left: 10px;
  display: flex;
  gap: 5px;
}

.skin-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.skin-preview-card {
  position: absolute;
  bottom: 10px; left: 10px; right: 10px;
  height: 24px;
  border-radius: 6px;
}

.skin-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 0 var(--space-xs) var(--space-xs);
}

.skin-name {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-primary);
}

.skin-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.skin-check {
  position: absolute;
  top: 8px; right: 8px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent-primary);
  color: var(--on-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 800;
}

/* Fixed preview palettes — must show each skin's own colors regardless of the active skin. */
[data-skin-preview="original"] { background: #0b0e17; }
[data-skin-preview="original"] .skin-preview-bar { background: linear-gradient(135deg, #38bdf8, #818cf8); }
[data-skin-preview="original"] .skin-preview-card { background: #1a2030; }
[data-skin-preview="original"] .skin-dot-1 { background: #38bdf8; }
[data-skin-preview="original"] .skin-dot-2 { background: #818cf8; }
[data-skin-preview="original"] .skin-dot-3 { background: #34d399; }

[data-skin-preview="washi"] { background: #f7f3ea; }
[data-skin-preview="washi"] .skin-preview-bar { background: linear-gradient(135deg, #5b7553, #46603f); }
[data-skin-preview="washi"] .skin-preview-card { background: #fffdf7; box-shadow: 0 1px 3px rgba(58, 48, 34, 0.14); }
[data-skin-preview="washi"] .skin-dot-1 { background: #5b7553; }
[data-skin-preview="washi"] .skin-dot-2 { background: #9a5a3b; }
[data-skin-preview="washi"] .skin-dot-3 { background: #cb8a2b; }

[data-skin-preview="tomoshibi"] { background: #1c1714; }
[data-skin-preview="tomoshibi"] .skin-preview-bar { background: linear-gradient(135deg, #e0a967, #c98a3e); }
[data-skin-preview="tomoshibi"] .skin-preview-card { background: #2a221d; }
[data-skin-preview="tomoshibi"] .skin-dot-1 { background: #e0a967; }
[data-skin-preview="tomoshibi"] .skin-dot-2 { background: #c99a6a; }
[data-skin-preview="tomoshibi"] .skin-dot-3 { background: #a3b18a; }