/* ==========================================
   KACE LEARN - DESIGN SYSTEM & STYLESHEET
   ========================================== */

:root {
  /* HSL Color Palette (Developer Theme) */
  --bg-main: hsl(222, 47%, 9%);       /* Deep Space */
  --bg-card: hsla(222, 47%, 15%, 0.7); /* Translucent Slate */
  --border-color: hsl(223, 27%, 24%);  /* Slate Border */

  --text-main: hsl(210, 40%, 98%);     /* Bright White/Blue */
  --text-muted: hsl(215, 20%, 65%);    /* Silver Gray */

  /* Accent Colors */
  --color-primary: hsl(263, 90%, 65%);   /* Electric Violet */
  --color-primary-hover: hsl(263, 90%, 70%);
  --color-secondary: hsl(217, 91%, 60%); /* Royal Blue */
  --color-accent: hsl(190, 95%, 50%);    /* Neon Cyan */

  /* Game State Colors */
  --color-success: hsl(142, 70%, 45%);   /* Emerald Green */
  --color-success-bg: hsla(142, 70%, 15%, 0.8);
  --color-success-border: hsl(142, 70%, 30%);

  --color-error: hsl(350, 85%, 55%);     /* Crimson Red */
  --color-error-bg: hsla(350, 85%, 15%, 0.8);
  --color-error-border: hsl(350, 85%, 30%);

  /* Utilities */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --font-family: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --shadow-glow: 0 0 20px hsla(263, 90%, 65%, 0.25);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.4);
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --bg-app-container: hsla(222, 47%, 6%, 0.5);
  --bg-validation-drawer: hsl(222, 47%, 6%);
}

:root[data-theme="light"] {
  /* HSL Color Palette (Light Developer Theme) */
  --bg-main: hsl(220, 30%, 95%);       /* Light blueish gray */
  --bg-card: hsla(220, 30%, 100%, 0.85); /* White glass */
  --border-color: hsl(220, 20%, 85%);  /* Light Gray Border */

  --text-main: hsl(222, 47%, 9%);     /* Dark Slate Text */
  --text-muted: hsl(215, 15%, 45%);    /* Soft gray-blue */

  /* Accent Colors */
  --color-primary: hsl(263, 70%, 55%);   /* Darker Violet for contrast */
  --color-primary-hover: hsl(263, 70%, 45%);
  --color-secondary: hsl(217, 80%, 50%); /* Mid Blue */
  --color-accent: hsl(190, 85%, 40%);    /* Darker Cyan */

  /* Game State Colors */
  --color-success: hsl(142, 60%, 35%);   /* Forest Green */
  --color-success-bg: hsla(142, 70%, 90%, 0.95);
  --color-success-border: hsl(142, 60%, 75%);

  --color-error: hsl(350, 75%, 45%);     /* Deep Red */
  --color-error-bg: hsla(350, 85%, 90%, 0.95);
  --color-error-border: hsl(350, 75%, 75%);

  --shadow-glow: 0 0 20px hsla(263, 70%, 55%, 0.15);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.08);
  --bg-app-container: hsla(220, 30%, 100%, 0.4);
  --bg-validation-drawer: hsl(220, 30%, 90%);
}

/* Reset & Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

.hidden {
  display: none !important;
}

/* Prevent Safari auto-zoom on input focus (font-size must be >= 16px) */
input, textarea, select {
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  height: 100dvh;
  width: 100vw;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  position: fixed;
  left: 0;
  top: 0;
  background-image:
    radial-gradient(at 0% 0%, hsla(263, 90%, 65%, 0.08) 0px, transparent 50%),
    radial-gradient(at 100% 100%, hsla(190, 95%, 50%, 0.08) 0px, transparent 50%);
}

/* Desktop-only aurora behind the glass app viewport. */
@media (min-width: 650px) {
  body::before {
    content: '';
    position: fixed;
    inset: -34vmax;
    z-index: -2;
    pointer-events: none;
    opacity: .72;
    background:
      radial-gradient(ellipse at 20% 32%, hsla(263, 95%, 68%, .58) 0 10%, transparent 34%),
      radial-gradient(ellipse at 76% 26%, hsla(190, 95%, 54%, .5) 0 11%, transparent 35%),
      radial-gradient(ellipse at 47% 77%, hsla(217, 91%, 62%, .38) 0 12%, transparent 38%),
      radial-gradient(ellipse at 85% 68%, hsla(282, 88%, 62%, .3) 0 9%, transparent 31%);
    filter: blur(54px) saturate(118%);
    transform: translate3d(-3%, -2%, 0) scale(1.04) rotate(-4deg);
    transform-origin: center;
    will-change: transform;
    animation: desktop-aurora-drift 32s ease-in-out infinite alternate;
  }

  :root[data-theme="light"] body::before {
    opacity: .32;
    filter: blur(58px) saturate(92%);
  }
}

@keyframes desktop-aurora-drift {
  0% { transform: translate3d(-3%, -2%, 0) scale(1.04) rotate(-4deg); }
  48% { transform: translate3d(4%, 3%, 0) scale(1.13) rotate(3deg); }
  100% { transform: translate3d(-1%, 5%, 0) scale(1.07) rotate(-1deg); }
}

@media (min-width: 650px) and (prefers-reduced-motion: reduce) {
  body::before {
    animation: none;
    will-change: auto;
  }
}

/* App Viewport Container */
.app-container {
  width: 100%;
  max-width: 650px;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  position: relative;
  padding: 0;
  overflow: hidden;
}

@media (min-width: 650px) {
  .app-container {
    height: 100dvh;
    max-height: none;
    border-left: 3px solid var(--border-color);
    border-right: 3px solid var(--border-color);
    border-top: none;
    border-bottom: none;
    border-radius: 0;
    background-color: var(--bg-app-container);
    backdrop-filter: blur(10px);
    box-shadow: 8px 0 0 rgba(0, 0, 0, 0.05), -8px 0 0 rgba(0, 0, 0, 0.05);
  }
}

/* Screens States */
.screen {
  display: none;
  flex-direction: column;
  width: 100%;
  height: 100%;
  max-height: 100%;
  flex: 1;
  min-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.screen.active {
  display: flex;
  opacity: 1;
}

/* Buttons */
.primary-btn {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  border: none;
  padding: 16px 32px;
  font-size: 1.1rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  cursor: pointer;
  box-shadow: var(--shadow-glow);
  transition: all var(--transition-fast);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.primary-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 0 25px hsla(263, 90%, 65%, 0.4);
  filter: brightness(1.1);
}

.primary-btn:active:not(:disabled) {
  transform: translateY(1px);
}

.primary-btn.disabled, .primary-btn:disabled {
  background: hsl(223, 15%, 20%);
  color: var(--text-muted);
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

.secondary-btn {
  background-color: transparent;
  color: var(--text-muted);
  border: 2px solid var(--border-color);
  padding: 16px 32px;
  font-size: 1.1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.secondary-btn:hover {
  border-color: var(--text-muted);
  color: var(--text-main);
  background-color: hsla(222, 47%, 20%, 0.3);
}

.icon-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 8px;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-btn:hover {
  color: var(--text-main);
}

/* 1. WELCOME SCREEN */
#welcome-screen {
  align-items: center;
  padding: 40px 24px;
  overflow-y: auto !important;
  overflow-x: hidden;
}

.welcome-card {
  width: 100%;
  max-width: 500px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin: 20px 0;
}

.logo-area h1 {
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -1px;
  margin-top: 10px;
  background: linear-gradient(135deg, var(--text-main) 30%, var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-area h1 span {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-area .mascot-avatar {
  font-size: 4.5rem;
  animation: float 4s ease-in-out infinite;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.6;
}

.config-section {
  display: flex;
  flex-direction: column;
  gap: 24px;
  text-align: left;
}

.config-group h3 {
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.radio-tiles {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.tile-option {
  position: relative;
  cursor: pointer;
}

.tile-option input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.tile-label {
  display: block;
  padding: 14px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 16px;
  font-weight: 700;
  text-align: center;
  transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  color: var(--text-muted);
  box-shadow: 0 4px 0 var(--border-color);
}

.tile-option:active .tile-label {
  transform: translateY(2px);
  box-shadow: 0 2px 0 var(--border-color);
}

.tile-option input:checked + .tile-label {
  border-color: #58cc02;
  background-color: #e8f5e9;
  color: #58cc02;
  box-shadow: 0 4px 0 #58cc02;
}

.tile-option:active input:checked + .tile-label {
  transform: translateY(2px);
  box-shadow: 0 2px 0 #58cc02;
}

.tile-option input:checked + .tile-label::after {
  content: '✓';
  position: absolute;
  top: -6px;
  right: -6px;
  width: 18px;
  height: 18px;
  background: #58cc02;
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: bold;
  border: 2px solid #fff;
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
}

.tile-option:hover .tile-label {
  border-color: color-mix(in srgb, var(--color-primary) 30%, var(--border-color));
  background-color: var(--bg-tertiary, #f7f7f7);
}

/* Animations */
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.pulse {
  animation: pulse-glow 2.5s infinite;
}

@keyframes pulse-glow {
  0% { box-shadow: 0 0 0 0 hsla(263, 90%, 65%, 0.4); }
  70% { box-shadow: 0 0 0 15px hsla(263, 90%, 65%, 0); }
  100% { box-shadow: 0 0 0 0 hsla(263, 90%, 65%, 0); }
}

/* 2. GAME SCREEN */
#game-screen {
  height: 100%;
  overflow: hidden;
}

.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  gap: 16px;
  border-bottom: 1px solid var(--border-color);
}

.infinite-stop-btn {
  min-height: 40px;
  padding: 7px 11px;
  flex: 0 0 auto;
  border: 2px solid var(--color-error-border);
  border-radius: 12px;
  background: var(--color-error-bg);
  color: var(--color-error);
  font: inherit;
  font-size: .76rem;
  font-weight: 900;
  cursor: pointer;
}
.infinite-stop-btn:hover { filter: brightness(.97); transform: translateY(-1px); }

.progress-bar-container {
  flex: 1;
  height: 16px;
  background-color: var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  position: relative;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), var(--color-secondary));
  border-radius: 8px;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 0 10px hsla(190, 95%, 50%, 0.4);
}

.hearts-container {
  display: flex;
  align-items: center;
  gap: 12px;
}

.score-badge {
  background-color: hsla(190, 95%, 50%, 0.1);
  border: 1px solid hsla(190, 95%, 50%, 0.3);
  color: var(--color-accent);
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 700;
}

.hearts-display {
  display: flex;
  gap: 4px;
  font-size: 1.25rem;
}

.heart {
  opacity: 0.3;
  transform: scale(0.85);
  transition: all var(--transition-fast);
}

.heart.active {
  opacity: 1;
  transform: scale(1);
  animation: heart-beat 1.2s infinite alternate;
}

@keyframes heart-beat {
  0% { transform: scale(1); }
  100% { transform: scale(1.1); }
}

.heart.shake {
  animation: shake 0.5s ease-in-out;
}

/* Game Content layout */
.game-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 24px 20px;
  gap: 20px;
  max-width: 550px;
  margin: 0 auto;
  width: 100%;
  overflow-y: auto;
}

.prompt-bubble-container {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  flex-shrink: 0;
}

.mascot-small {
  font-size: 2.5rem;
}

.speech-bubble {
  position: relative;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  padding: 16px 20px;
  border-radius: var(--radius-md);
  flex: 1;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.speech-bubble::before {
  content: '';
  position: absolute;
  left: -10px;
  top: 18px;
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-right: 10px solid var(--border-color);
}

.speech-bubble::after {
  content: '';
  position: absolute;
  left: -7px;
  top: 18px;
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-right: 10px solid hsl(222, 47%, 15%);
}

.instruction {
  color: var(--text-muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
  font-weight: 600;
}

#vietnamese-sentence {
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.4;
}

/* Interactive Workspace Styles */
.workspace {
  min-height: 100px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  flex-shrink: 0;
}

/* Optional image attached to a quiz-deck question. */
.quiz-question-image {
  display: flex;
  justify-content: center;
  width: 100%;
  min-height: 64px;
  margin: 2px 0 18px;
  overflow: hidden;
  border: 2px solid var(--border-color);
  border-radius: 16px;
  background: var(--bg-card);
}
.quiz-question-image.loading::after { content: 'Đang tải ảnh…'; align-self: center; color: var(--text-muted); font-size: .85rem; }
.quiz-question-image img { display: block; width: 100%; max-height: min(42vh, 380px); object-fit: contain; }
.quiz-question-image.loading img { display: none; }

/* Workspace Specifics: Sentence Builder */
.sentence-slots {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 16px;
  border-bottom: 2px dashed var(--border-color);
  min-height: 70px;
  align-items: center;
}

.sentence-slots:focus {
  outline: none;
  border-bottom-color: var(--color-primary);
}

/* Tiles Styling */
.word-tile {
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-bottom-width: 4px;
  color: var(--text-main);
  padding: 10px 18px;
  font-size: 1.05rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  user-select: none;
  transition: transform var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
  display: inline-block;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.word-tile:hover {
  border-color: var(--text-muted);
  /* Keep the hit area stationary: moving a hovered tile can make :hover flicker
     when the pointer is close to its lower edge. */
  box-shadow: 0 4px 8px rgba(0,0,0,0.24);
}

.word-tile:active {
  transform: translateY(1px);
  border-bottom-width: 2px;
  margin-top: 2px;
}

.word-tile.used {
  opacity: 0.15;
  cursor: default;
  pointer-events: none;
  transform: none !important;
  border-bottom-width: 2px;
}

/* Options Container: Word Tiles */
.options-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  min-height: 100px;
  align-content: flex-start;
  flex-shrink: 0;
}

/* Workspace Specifics: Fill in the Blank */
.fill-blank-sentence {
  font-size: 1.5rem;
  font-weight: 600;
  text-align: center;
  line-height: 1.8;
  letter-spacing: 0.5px;
}

.blank-slot {
  display: inline-block;
  min-width: 90px;
  border-bottom: 3px dashed var(--color-primary);
  margin: 0 10px;
  text-align: center;
  color: var(--color-accent);
  padding-bottom: 2px;
  font-weight: 700;
}

.blank-slot.filled {
  border-bottom-style: solid;
  color: var(--color-primary);
  animation: scale-up 0.2s ease-out;
}

/* Workspace Specifics: Multiple Choice Cards */
.choice-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
}

.choice-card {
  display: flex;
  align-items: center;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-bottom-width: 4px;
  border-radius: var(--radius-md);
  padding: 16px 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  user-select: none;
  color: var(--text-main);
  font-family: inherit;
}

.choice-card:hover {
  border-color: var(--text-muted);
  box-shadow: 0 4px 8px rgba(0,0,0,0.18);
}

.choice-card:active {
  transform: translateY(1px);
  border-bottom-width: 2px;
}

.choice-card.selected {
  border-color: var(--color-primary);
  background-color: hsla(263, 90%, 65%, 0.08);
  box-shadow: 0 0 15px hsla(263, 90%, 65%, 0.1);
}

.choice-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  margin-right: 16px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.choice-card.selected .choice-number {
  border-color: var(--color-primary);
  background-color: var(--color-primary);
  color: #fff;
}

.choice-text {
  font-size: 1.1rem;
  font-weight: 600;
  flex: 1;
}

/* 3. VALIDATION BOTTOM DRAWER */
.validation-drawer {
  position: relative;
  background-color: var(--bg-validation-drawer);
  border-top: 2px solid var(--border-color);
  padding: 20px 24px;
  transition: all var(--transition-normal);
  z-index: 100;
  width: 100%;
}



.drawer-inner {
  max-width: 550px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.drawer-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Feedback message container */
.feedback-message {
  display: none;
  font-size: 1.1rem;
  font-weight: 700;
  align-items: center;
  gap: 12px;
  animation: slide-up-subtle 0.25s cubic-bezier(0.18, 0.89, 0.32, 1.28);
}

.feedback-message svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
}

.feedback-details {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.feedback-correct-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  font-weight: 600;
  opacity: 0.8;
}

/* Drawer States (Correct/Incorrect) */
.validation-drawer.correct {
  background-color: var(--color-success-bg);
  border-top-color: var(--color-success-border);
}

.validation-drawer.correct .feedback-message {
  display: flex;
  color: var(--color-success);
}

.validation-drawer.correct #check-btn {
  background: var(--color-success) !important;
  box-shadow: 0 0 15px hsla(142, 70%, 45%, 0.4);
}

.validation-drawer.incorrect {
  background-color: var(--color-error-bg);
  border-top-color: var(--color-error-border);
}

.validation-drawer.incorrect .feedback-message {
  display: flex;
  color: var(--color-error);
}

.validation-drawer.incorrect #check-btn {
  background: var(--color-error) !important;
  box-shadow: 0 0 15px hsla(350, 85%, 55%, 0.4);
}

/* Key Helper Style */
.keyboard-help {
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-muted);
  pointer-events: none;
  padding: 8px 0;
  width: 100%;
  display: none;
}

@media (min-width: 650px) {
  .keyboard-help {
    display: block;
  }
}

/* 4. RESULT SCREEN */
#result-screen {
  align-items: center;
  padding: 40px 24px;
  overflow-y: auto !important;
  overflow-x: hidden;
}

.result-card {
  width: 100%;
  max-width: 500px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin: 20px 0;
}

.trophy-icon {
  font-size: 5rem;
  animation: bounce-rotate 1.5s ease infinite alternate;
}

.result-subtitle {
  color: var(--text-muted);
  margin-top: -10px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(88px, 1fr));
  gap: 12px;
  margin: 10px 0;
}

.stat-card {
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  padding: 16px 8px;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-accent);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
}

.review-section {
  text-align: left;
  display: flex;
  flex-direction: column;
  max-height: 250px;
  overflow-y: auto;
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 20px;
  background-color: var(--bg-card);
  box-shadow: 0 4px 0 var(--border-color);
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

.review-section h3 {
  margin: 0 0 16px;
  font-size: 1.05rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.review-section::-webkit-scrollbar {
  width: 6px;
}
.review-section::-webkit-scrollbar-thumb {
  background-color: var(--border-color);
  border-radius: 3px;
}

.review-list {
  display: flex;
  flex-direction: column;
}

.review-item {
  display: flex;
  gap: 14px;
  font-size: 0.92rem;
  line-height: 1.4;
  padding: 12px 0;
  border-bottom: 2px solid var(--border-color);
}

.review-item:first-child {
  padding-top: 0;
}

.review-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.review-status-icon {
  font-size: 1.2rem;
  flex-shrink: 0;
  display: flex;
  align-items: flex-start;
  padding-top: 2px;
}

.review-details {
  flex: 1;
}

.review-vi {
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 4px;
  font-size: 0.95rem;
}

.review-eng {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
}

.review-eng.wrong {
  color: #ea2b2b;
  text-decoration: line-through;
  margin-right: 8px;
}

.review-correct {
  color: #58cc02;
  font-weight: 700;
  font-size: 0.88rem;
}

/* Animations */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.shake-active {
  animation: shake 0.4s ease-in-out;
}

@keyframes bounce-rotate {
  0% { transform: scale(1) rotate(0deg); }
  100% { transform: scale(1.1) rotate(10deg); }
}

@keyframes scale-up {
  0% { transform: scale(0.9); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes slide-up-subtle {
  0% { transform: translateY(15px); opacity: 0; }
  100% { transform: translateY(0); opacity: 1; }
}

/* Confetti styling for complete state */
.confetti {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 999;
  animation: confetti-fall 3s ease-out forwards;
}

@keyframes confetti-fall {
  0% { transform: translateY(-50px) rotate(0deg); opacity: 1; }
  100% { transform: translateY(800px) rotate(720deg); opacity: 0; }
}

/* Custom Scrollbar Styles for consistent look */
#welcome-screen,
#result-screen,
.game-content {
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

#welcome-screen::-webkit-scrollbar,
#result-screen::-webkit-scrollbar,
.game-content::-webkit-scrollbar {
  width: 6px;
}

#welcome-screen::-webkit-scrollbar-thumb,
#result-screen::-webkit-scrollbar-thumb,
.game-content::-webkit-scrollbar-thumb {
  background-color: var(--border-color);
  border-radius: 3px;
}

/* Matching Card Layout and Card States */
.matching-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  width: 100%;
  margin-top: 10px;
}

.matching-column {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.matching-card {
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-bottom-width: 4px;
  border-radius: var(--radius-md);
  padding: 16px 12px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
  user-select: none;
  color: var(--text-main);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  min-height: 70px;
}

.matching-card:hover:not(.matched) {
  border-color: var(--text-muted);
  box-shadow: 0 4px 8px rgba(0,0,0,0.18);
}

.matching-card:active:not(.matched) {
  transform: translateY(1px);
  border-bottom-width: 2px;
}

.matching-card.selected {
  border-color: var(--color-primary);
  background-color: hsla(263, 90%, 65%, 0.12);
  box-shadow: 0 0 15px hsla(263, 90%, 65%, 0.15);
}

.matching-card.matched {
  border-color: var(--color-success-border);
  background-color: var(--color-success-bg);
  color: var(--color-success);
  opacity: 0.4;
  cursor: default;
  pointer-events: none;
  border-bottom-width: 2px;
  transform: none !important;
}

.matching-card.wrong {
  border-color: var(--color-error-border);
  background-color: var(--color-error-bg);
  color: var(--color-error);
  animation: shake 0.4s ease-in-out;
}

/* Typing Card / Input Styling */
.typing-container {
  display: flex;
  width: 100%;
  padding: 10px 0;
  flex-shrink: 0;
}

.typing-input {
  width: 100%;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  color: var(--text-main);
  font-family: inherit;
  font-size: 1.25rem;
  font-weight: 600;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: var(--shadow-card);
}

.typing-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 15px hsla(263, 90%, 65%, 0.15);
}

.typing-input::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

/* Listening Mode Styles */
.listening-workspace {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  gap: 12px;
  margin-bottom: 16px;
  flex-shrink: 0;
}

.speaker-container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 90px;
}

.speaker-btn {
  width: 76px;
  height: 76px;
  border-radius: 50%;
  background-color: hsla(263, 90%, 65%, 0.12);
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  outline: none;
  transition: all var(--transition-fast);
  box-shadow: 0 0 10px hsla(263, 90%, 65%, 0.1);
  position: relative;
}

.speaker-btn:hover {
  transform: scale(1.06);
  background-color: hsla(263, 90%, 65%, 0.22);
  box-shadow: 0 0 20px hsla(263, 90%, 65%, 0.3);
}

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

.speaker-btn svg {
  width: 32px;
  height: 32px;
  fill: currentColor;
}

/* Speaker pulse wave animation */
.speaker-btn::after {
  content: '';
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  border-radius: 50%;
  border: 2px solid var(--color-primary);
  opacity: 0;
  pointer-events: none;
}

.speaker-btn.playing::after {
  animation: speakerPulse 1.2s cubic-bezier(0.24, 0, 0.38, 1) infinite;
}

@keyframes speakerPulse {
  0% {
    transform: scale(1);
    opacity: 0.8;
  }
  100% {
    transform: scale(1.4);
    opacity: 0;
  }
}

.hint-toggle-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: underline;
  cursor: pointer;
  transition: color var(--transition-fast);
  padding: 4px 8px;
}

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

.hint-text {
  font-size: 1.1rem;
  color: var(--color-primary);
  font-weight: 600;
  text-align: center;
  min-height: 24px;
  opacity: 0;
  transition: opacity 0.3s ease;
  background-color: hsla(263, 90%, 65%, 0.05);
  padding: 6px 16px;
  border-radius: var(--radius-sm);
  border: 1px dashed hsla(263, 90%, 65%, 0.2);
}

.hint-text.visible {
  opacity: 1;
}

/* Light mode specific background override */
:root[data-theme="light"] body {
  background-image:
    radial-gradient(at 0% 0%, hsla(263, 70%, 55%, 0.04) 0px, transparent 50%),
    radial-gradient(at 100% 100%, hsla(190, 85%, 40%, 0.04) 0px, transparent 50%);
}

/* Smooth Transitions */
body, .app-container, .screen, .welcome-card, .result-card, .speech-bubble, .choice-card, .word-tile, .matching-card, .typing-input, .primary-btn, .secondary-btn, .game-header, .validation-drawer, .stat-card, .review-item {
  transition: background-color var(--transition-normal), border-color var(--transition-normal), color var(--transition-normal), box-shadow var(--transition-normal);
}

/* Theme Toggle Button Styles (Duolingo Pill Switch Style) */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px;
  border-radius: 20px;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  box-shadow: 0 3px 0 var(--border-color);
  cursor: pointer;
  position: relative;
  width: 76px;
  height: 38px;
  box-sizing: border-box;
  overflow: hidden;
  user-select: none;
  z-index: 100;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle-btn:hover {
  transform: scale(1.05);
}

.theme-toggle-btn:active {
  transform: scale(0.98);
}

.toggle-sun {
  position: absolute;
  left: 8px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 1;
  font-size: 0.95rem;
  pointer-events: none;
  line-height: 1;
}

.toggle-moon {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 1;
  font-size: 0.95rem;
  pointer-events: none;
  line-height: 1;
}

.duo-toggle-knob {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: inline-block;
  transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
  position: absolute;
  top: 6px;
  left: 6px;
  z-index: 2;
  flex-shrink: 0;
}

.duo-toggle-knob.light {
  transform: translateX(0px);
  background: #ff9600;
}

.duo-toggle-knob.dark {
  transform: translateX(38px);
  background: var(--color-primary);
}

/* Floating screen positioning */
.result-theme-toggle {
  position: absolute;
  top: 20px;
  right: 20px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  box-shadow: var(--shadow-glow);
}

/* Subtitles / extra light theme styles */
:root[data-theme="light"] .score-badge {
  background-color: hsla(190, 85%, 40%, 0.08);
  border-color: hsla(190, 85%, 40%, 0.25);
  color: hsl(190, 85%, 35%);
}

:root[data-theme="light"] .mascot-avatar {
  background-color: hsla(263, 70%, 55%, 0.08);
}

/* Light mode specific button overrides */
:root[data-theme="light"] .primary-btn.disabled,
:root[data-theme="light"] .primary-btn:disabled {
  background: hsl(220, 20%, 80%) !important;
  color: hsl(220, 10%, 55%) !important;
}

:root[data-theme="light"] .secondary-btn:hover {
  background-color: hsla(220, 30%, 80%, 0.4);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* --- User Profile & Auth Styles --- */
.welcome-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 0 14px;
  position: absolute;
  top: 16px;
  left: 0;
  z-index: 10;
}

#user-profile-area {
  display: flex;
  align-items: center;
  gap: 10px;
}

.google-login-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 8px 16px;
  border-radius: 50px;
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}
.google-login-btn:hover {
  background: var(--bg-main);
  border-color: var(--color-primary);
}

.google-login-btn svg {
  flex-shrink: 0;
}

.welcome-user-chip {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 4px 12px 4px 4px;
  border-radius: 50px;
  text-decoration: none;
  color: var(--text-main);
  transition: border-color var(--transition-fast);
}
.welcome-user-chip:hover {
  border-color: var(--color-primary);
}

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

.welcome-user-chip .username {
  font-size: 0.85rem;
  font-weight: 600;
  max-width: 100px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.welcome-user-chip .manage-link {
  font-size: 0.75rem;
  color: var(--color-primary);
  font-weight: 700;
  margin-left: 4px;
}

/* Deck dropdown */
.deck-dropdown {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 2px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-family);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition-fast);
}
.deck-dropdown:focus {
  border-color: var(--color-primary);
}

/* Auth error alert */
.auth-error-alert {
  padding: 12px 16px;
  background: var(--color-error-bg);
  border: 1px solid var(--color-error-border);
  color: var(--color-error);
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  margin-bottom: 16px;
  text-align: left;
}

/* ── Duolingo Home Page Overrides ── */
.top-bar-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Compact welcome header controls */
.topbar-icon-btn,
.leaderboard-toggle-btn,
.welcome-theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1.5px solid var(--border-color);
  border-radius: 10px;
  background: var(--bg-card);
  color: var(--text-main);
  box-shadow: 0 2px 0 var(--border-color);
  font: inherit;
  font-size: 1rem;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.topbar-icon-btn:hover,
.leaderboard-toggle-btn:hover,
.welcome-theme-toggle:hover {
  transform: translateY(-1px);
  border-color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 10%, var(--bg-card));
}
.topbar-icon-btn:active,
.leaderboard-toggle-btn:active,
.welcome-theme-toggle:active {
  transform: translateY(1px);
  box-shadow: none;
}
.topbar-icon-btn:focus-visible,
.leaderboard-toggle-btn:focus-visible,
.welcome-theme-toggle:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--color-primary) 42%, transparent);
  outline-offset: 2px;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Streak Counter Badge */
.streak-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-width: 43px;
  height: 34px;
  padding: 0 8px;
  background: color-mix(in srgb, #ff9600 10%, var(--bg-card));
  border: 1.5px solid #ff9600;
  color: #ff9600;
  border-radius: 10px;
  font-weight: 800;
  font-size: 0.8rem;
  box-shadow: 0 2px 0 color-mix(in srgb, #ff9600 70%, var(--border-color));
  transition: transform var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
}
.streak-badge:hover {
  transform: translateY(-1px);
  background: color-mix(in srgb, #ff9600 17%, var(--bg-card));
}

/* Duolingo Profile Chip on Home Screen */
.duo-profile-chip {
  display: flex;
  align-items: center;
  gap: 7px;
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  padding: 3px 4px 3px 3px;
  border-radius: 12px;
  box-shadow: 0 2px 0 var(--border-color);
}

.duo-profile-chip img.user-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  object-fit: cover;
  border: 1.5px solid #fff;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.duo-profile-chip .user-name {
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--text-main);
  max-width: 88px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.duo-profile-chip .manage-badge-btn {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  border-color: color-mix(in srgb, var(--color-primary) 55%, var(--border-color));
  box-shadow: none;
  font-size: .88rem;
  background: color-mix(in srgb, var(--color-primary) 8%, var(--bg-card));
  color: var(--color-primary);
}
.duo-profile-chip .manage-badge-btn:hover {
  background: var(--color-primary);
  color: #fff;
}

.welcome-theme-toggle {
  border-radius: 50%;
  overflow: visible;
  z-index: 10;
}
.welcome-theme-toggle .compact-theme-icon { font-size: 1rem; line-height: 1; }
.welcome-theme-toggle .toggle-sun,
.welcome-theme-toggle .toggle-moon,
.welcome-theme-toggle .duo-toggle-knob { display: none; }

/* Green Config Headers (Dynamic Theme-based primary color) */
.config-group h3 {
  color: var(--color-primary) !important;
  font-weight: 800 !important;
  font-size: 0.88rem !important;
  letter-spacing: 0.05em !important;
  margin-bottom: 12px !important;
  display: flex !important;
  align-items: center !important;
  gap: 8px !important;
  text-transform: uppercase !important;
}

/* Option tile active colors using dynamic primary color */
.tile-option input:checked + .tile-label {
  border-color: var(--color-primary) !important;
  background-color: color-mix(in srgb, var(--color-primary) 10%, var(--bg-card)) !important;
  color: var(--color-primary) !important;
  box-shadow: 0 4px 0 var(--color-primary) !important;
}
.tile-option input:checked + .tile-label::after {
  background: var(--color-primary) !important;
}

/* Custom Deck Selector Dropdown */
.deck-dropdown {
  border-radius: 16px !important;
  border: 2px solid var(--border-color) !important;
  box-shadow: 0 3px 0 var(--border-color) !important;
  font-weight: 700 !important;
  padding: 12px 20px !important;
}

/* Bouncy Green Duolingo Start Button (Dynamic Theme-based primary color) */
#start-btn {
  background: var(--color-primary) !important;
  color: #fff !important;
  border: none !important;
  border-bottom: 5px solid color-mix(in srgb, var(--color-primary) 70%, black) !important;
  box-shadow: none !important;
  border-radius: 16px !important;
  padding: 14px 32px !important;
  font-weight: 800 !important;
  font-size: 1.1rem !important;
  letter-spacing: 0.05em !important;
  width: 100% !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 8px !important;
  transition: transform 0.1s ease, border-bottom-width 0.1s ease !important;
  text-shadow: 0 1px 2px rgba(0,0,0,0.1);
  box-sizing: border-box;
  margin-top: 10px;
}
#start-btn:active {
  transform: translateY(3px) !important;
  border-bottom-width: 2px !important;
}



/* Mascot layout alignment */
.mascot-illustration {
  margin-bottom: 12px;
  display: flex;
  justify-content: center;
}

/* Duolingo Rolling Hills CSS Backdrop at the bottom */
body::after {
  content: '';
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 120px;
  background-image:
    radial-gradient(ellipse at 30% 120%, #78c800 50%, transparent 55%),
    radial-gradient(ellipse at 70% 120%, #58a700 55%, transparent 60%);
  background-size: 100% 120px;
  z-index: -1;
  pointer-events: none;
  opacity: 0.45;
}
:root[data-theme="dark"] body::after {
  opacity: 0.15; /* Subtler in dark mode */
}

/* ── Mobile Layout Optimization for Top Bar ── */
@media (max-width: 480px) {
  .welcome-top-bar {
    padding: 0 8px !important;
    top: 8px !important;
  }
  .duo-profile-chip {
    padding: 3px !important;
    gap: 0 !important;
  }
  .duo-profile-chip .user-name {
    display: none !important; /* Hide name on mobile viewports to prevent layout overflow */
  }
  .top-bar-right {
    gap: 5px !important;
  }
  .streak-badge {
    min-width: 38px !important;
    height: 31px !important;
    padding: 0 6px !important;
    font-size: 0.76rem !important;
  }
  .topbar-icon-btn,
  .leaderboard-toggle-btn,
  .welcome-theme-toggle {
    width: 31px;
    height: 31px;
  }
  .duo-profile-chip .manage-badge-btn {
    display: none;
  }
}

/* ── Streak Celebration Overlay ── */
.streak-celebration-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  animation: fadeIn 0.3s ease forwards;
}

.streak-celebration-card {
  background: var(--bg-card);
  border: 3px solid var(--border-color);
  border-radius: 28px;
  padding: 32px;
  max-width: 420px;
  width: 90%;
  text-align: center;
  box-shadow: 0 12px 0 var(--border-color);
  animation: popIn 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
  box-sizing: border-box;
}

/* Fire animations */
.streak-fire-wrapper {
  position: relative;
  width: 160px;
  height: 160px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.streak-huge-fire {
  font-size: 8rem;
  line-height: 1;
  animation: burn 1.2s ease-in-out infinite alternate;
  filter: drop-shadow(0 4px 10px rgba(255, 69, 0, 0.3));
}

.streak-huge-number {
  position: absolute;
  font-size: 2.8rem;
  font-weight: 900;
  color: #ffffff;
  top: 55%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-shadow:
    -3px -3px 0 #000,
     3px -3px 0 #000,
    -3px  3px 0 #000,
     3px  3px 0 #000,
     0px  4px 0 #ff4500;
  animation: pulseNumber 1.2s ease-in-out infinite alternate;
}

.streak-title {
  color: #ff8c00;
  font-size: 1.8rem;
  font-weight: 800;
  margin: 10px 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-shadow: 0 2px 0 rgba(0,0,0,0.05);
}

.streak-desc {
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.streak-continue-btn {
  background: #ff8c00 !important;
  border-bottom: 5px solid #cc7000 !important;
  color: #fff !important;
  padding: 14px 32px !important;
  font-size: 1.1rem !important;
  font-weight: 800 !important;
  border-radius: 16px !important;
  width: 100% !important;
  cursor: pointer;
  transition: transform 0.1s ease, border-bottom-width 0.1s ease !important;
}

.streak-continue-btn:active {
  transform: translateY(3px) !important;
  border-bottom-width: 2px !important;
}

/* Confetti particles inside the streak popup */
.streak-spark {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  opacity: 1;
  animation: flyOut 1.5s cubic-bezier(0.1, 0.8, 0.3, 1) forwards;
}

/* Animations declarations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

@keyframes burn {
  from { transform: scale(0.95) rotate(-2deg); }
  to { transform: scale(1.05) rotate(2deg); }
}

@keyframes pulseNumber {
  from { transform: translate(-50%, -50%) scale(0.95); }
  to { transform: translate(-50%, -50%) scale(1.05); }
}

@keyframes flyOut {
  to {
    transform: translate(var(--x-dest), var(--y-dest)) scale(0);
    opacity: 0;
  }
}

.streak-celebration-overlay.fade-out {
  opacity: 0;
  transition: opacity 0.4s ease;
}


/* ==========================================
   AI CHAT — Floating Panel Styles
   ========================================== */

/* Floating Action Button */
.ai-chat-fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9000;
  display: flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  border: none;
  border-radius: 50px;
  padding: 14px 20px;
  cursor: pointer;
  font-family: var(--font-family);
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: 0 4px 0 hsla(263, 90%, 40%, 0.6), 0 8px 24px hsla(263, 90%, 60%, 0.35);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  user-select: none;
  animation: ai-fab-pulse 3s ease-in-out infinite;
}

.ai-chat-fab:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 0 hsla(263, 90%, 40%, 0.6), 0 12px 32px hsla(263, 90%, 60%, 0.4);
}

.ai-chat-fab:active {
  transform: translateY(1px);
  box-shadow: 0 2px 0 hsla(263, 90%, 40%, 0.6), 0 4px 12px hsla(263, 90%, 60%, 0.3);
}

.ai-chat-fab-icon {
  font-size: 1.3rem;
  line-height: 1;
}

.ai-chat-fab-label {
  letter-spacing: 0.03em;
}

@keyframes ai-fab-pulse {
  0%, 100% { box-shadow: 0 4px 0 hsla(263, 90%, 40%, 0.6), 0 8px 24px hsla(263, 90%, 60%, 0.35); }
  50% { box-shadow: 0 4px 0 hsla(263, 90%, 40%, 0.6), 0 8px 32px hsla(263, 90%, 65%, 0.55); }
}

/* Chat Panel */
.ai-chat-panel {
  position: fixed;
  bottom: 90px;
  right: 24px;
  z-index: 9001;
  width: 380px;
  max-width: calc(100vw - 32px);
  max-height: 580px;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 24px;
  box-shadow: 0 6px 0 var(--border-color), 0 16px 48px rgba(0,0,0,0.4);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: ai-panel-slidein 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

@keyframes ai-panel-slidein {
  from { opacity: 0; transform: translateY(20px) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

/* Panel Header */
.ai-chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  flex-shrink: 0;
}

.ai-chat-header-info {
  display: flex;
  align-items: center;
  gap: 10px;
}

.ai-chat-header-icon {
  font-size: 1.6rem;
  line-height: 1;
}

.ai-chat-header-title {
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: 0.02em;
}

.ai-chat-header-sub {
  font-size: 0.78rem;
  opacity: 0.85;
  font-weight: 500;
  margin-top: 1px;
  max-width: 200px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.ai-chat-header-actions {
  display: flex;
  gap: 6px;
}

.ai-chat-icon-btn {
  background: rgba(255,255,255,0.15);
  border: none;
  color: #fff;
  border-radius: 8px;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 700;
  transition: background 0.15s;
}

.ai-chat-icon-btn:hover {
  background: rgba(255,255,255,0.28);
}

/* Topic Selector Screen */
.ai-chat-topic-screen {
  padding: 18px;
  overflow-y: auto;
  flex: 1;
}

.ai-chat-topic-intro {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 14px;
}

.ai-chat-topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 14px;
}

.ai-chat-topic-chip {
  background: var(--bg-main);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 10px 12px;
  font-family: var(--font-family);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-main);
  cursor: pointer;
  text-align: center;
  transition: all 0.15s ease;
  box-shadow: 0 3px 0 var(--border-color);
  line-height: 1.3;
}

.ai-chat-topic-chip:hover {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 5px 0 hsla(263, 90%, 40%, 0.5);
}

.ai-chat-topic-chip:active {
  transform: translateY(1px);
  box-shadow: 0 1px 0 var(--border-color);
}

.ai-chat-custom-topic {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.ai-chat-custom-topic input {
  flex: 1;
  background: var(--bg-main);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  padding: 10px 14px;
  font-family: var(--font-family);
  font-size: 0.85rem;
  color: var(--text-main);
  outline: none;
  transition: border-color 0.15s;
}

.ai-chat-custom-topic input:focus {
  border-color: var(--color-primary);
}

.ai-chat-custom-topic input::placeholder {
  color: var(--text-muted);
}

.ai-chat-custom-go {
  background: var(--color-primary);
  border: 2px solid var(--color-primary);
  border-radius: 12px;
  color: #fff;
  font-size: 1.1rem;
  font-weight: 700;
  width: 44px;
  height: 44px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
  box-shadow: 0 3px 0 hsla(263, 90%, 40%, 0.5);
  flex-shrink: 0;
}

.ai-chat-custom-go:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
}

/* Chat Messages Screen */
.ai-chat-chat-screen {
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
  min-height: 0;
}

.ai-chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

.ai-chat-messages::-webkit-scrollbar { width: 4px; }
.ai-chat-messages::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 2px;
}

/* Message Bubbles */
.ai-chat-bubble {
  max-width: 85%;
  padding: 10px 14px;
  border-radius: 18px;
  font-size: 0.88rem;
  line-height: 1.5;
  word-break: break-word;
  animation: ai-bubble-in 0.2s ease;
}

@keyframes ai-bubble-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.ai-chat-bubble.ai {
  background: var(--bg-main);
  border: 2px solid var(--border-color);
  color: var(--text-main);
  align-self: flex-start;
  border-bottom-left-radius: 6px;
  font-weight: 500;
}

.ai-chat-bubble.user {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  align-self: flex-end;
  border-bottom-right-radius: 6px;
  font-weight: 600;
}

.ai-chat-bubble.correction {
  background: var(--color-success-bg);
  border: 2px solid var(--color-success-border);
  color: var(--text-main);
  align-self: flex-start;
  border-bottom-left-radius: 6px;
  font-size: 0.84rem;
}

.ai-chat-bubble.correction::before {
  content: "✅ Correction:";
  font-weight: 800;
  color: var(--color-success);
  display: block;
  margin-bottom: 4px;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Loading dots bubble */
.ai-chat-bubble.loading {
  background: var(--bg-main);
  border: 2px solid var(--border-color);
  align-self: flex-start;
  border-bottom-left-radius: 6px;
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 12px 16px;
}

.ai-chat-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-muted);
  animation: ai-dot-bounce 1.2s ease-in-out infinite;
}

.ai-chat-dot:nth-child(2) { animation-delay: 0.2s; }
.ai-chat-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes ai-dot-bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.5; }
  40% { transform: translateY(-6px); opacity: 1; }
}

/* Input Bar */
.ai-chat-input-bar {
  padding: 12px 14px 14px;
  border-top: 2px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--bg-card);
  flex-shrink: 0;
}

.ai-chat-input-row {
  display: flex;
  gap: 8px;
}

.ai-chat-input-bar input {
  flex: 1;
  background: var(--bg-main);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 10px 14px;
  font-family: var(--font-family);
  font-size: 0.88rem;
  color: var(--text-main);
  outline: none;
  transition: border-color 0.15s;
}

.ai-chat-input-bar input:focus {
  border-color: var(--color-primary);
}

.ai-chat-input-bar input::placeholder {
  color: var(--text-muted);
}

.ai-chat-send-btn {
  background: var(--color-primary);
  border: 2px solid var(--color-primary);
  border-radius: 14px;
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  width: 44px;
  height: 44px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
  box-shadow: 0 3px 0 hsla(263, 90%, 40%, 0.5);
  flex-shrink: 0;
}

.ai-chat-send-btn:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
}

.ai-chat-send-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.ai-chat-correct-btn {
  background: transparent;
  border: 2px solid var(--border-color);
  border-radius: 12px;
  color: var(--text-muted);
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 7px 14px;
  cursor: pointer;
  transition: all 0.15s;
  text-align: center;
  width: 100%;
}

.ai-chat-correct-btn:hover {
  border-color: var(--color-success);
  color: var(--color-success);
  background: var(--color-success-bg);
}

.ai-chat-correct-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* Mobile adjustments */
@media (max-width: 480px) {
  .ai-chat-fab {
    bottom: 16px;
    right: 16px;
    padding: 12px 16px;
    font-size: 0.85rem;
  }

  .ai-chat-panel {
    bottom: 80px;
    right: 16px;
    left: 16px;
    width: auto;
    max-height: 70vh;
  }
}

/* AI Chat — Translate button & translation display */
.ai-chat-bubble-wrapper {
  display: flex;
  flex-direction: column;
  align-self: flex-start;
  max-width: 85%;
  gap: 4px;
  animation: ai-bubble-in 0.2s ease;
}

.ai-chat-translate-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.75rem;
  font-family: var(--font-family);
  font-weight: 600;
  color: var(--text-muted);
  padding: 2px 4px;
  text-align: left;
  transition: color 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  opacity: 0.7;
}

.ai-chat-translate-btn:hover {
  color: var(--color-secondary);
  opacity: 1;
}

.ai-chat-translate-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.ai-chat-translation {
  background: hsla(217, 91%, 60%, 0.08);
  border: 1.5px solid hsla(217, 91%, 60%, 0.25);
  border-radius: 12px;
  border-top-left-radius: 4px;
  padding: 8px 12px;
  font-size: 0.83rem;
  font-weight: 500;
  color: var(--text-main);
  line-height: 1.5;
  animation: ai-bubble-in 0.2s ease;
}

.ai-chat-translation-label {
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 3px;
}


/* ==========================================
   STREAK LEADERBOARD — Modal Overlay & Card
   ========================================== */

/* Toggle Button in welcome header */
.leaderboard-toggle-btn {
  font-size: 1rem;
}

.leaderboard-toggle-btn:hover {
  transform: translateY(-1px);
  border-color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 10%, var(--bg-card));
}

.leaderboard-toggle-btn:active {
  transform: translateY(1px);
  box-shadow: none;
}

/* Modal overlay with glassmorphism blur */
.leaderboard-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.6);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  animation: leaderboard-fadein 0.25s ease;
}

@keyframes leaderboard-fadein {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Duolingo-styled modal */
.leaderboard-modal {
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 24px;
  box-shadow: 0 8px 0 var(--border-color), 0 20px 50px rgba(0, 0, 0, 0.5);
  width: 440px;
  max-width: calc(100vw - 32px);
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: leaderboard-slideup 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

@keyframes leaderboard-slideup {
  from { transform: translateY(30px) scale(0.95); opacity: 0; }
  to { transform: translateY(0) scale(1); opacity: 1; }
}

.leaderboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 2px solid var(--border-color);
  flex-shrink: 0;
}

.leaderboard-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 0;
}

.leaderboard-close-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.15rem;
  font-weight: 700;
  cursor: pointer;
  transition: color 0.15s;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.leaderboard-close-btn:hover {
  color: var(--color-error);
}

.leaderboard-content {
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
  position: relative;
}

.leaderboard-list-header {
  display: grid;
  grid-template-columns: 60px 1fr 100px;
  padding: 10px 24px;
  border-bottom: 2px solid var(--border-color);
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: hsla(222, 47%, 5%, 0.15);
  flex-shrink: 0;
}

.leaderboard-list {
  overflow-y: auto;
  flex: 1;
  padding: 8px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

.leaderboard-list::-webkit-scrollbar {
  width: 6px;
}
.leaderboard-list::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

/* User rank row */
.leaderboard-row {
  display: grid;
  grid-template-columns: 60px 1fr 100px;
  align-items: center;
  padding: 12px 24px;
  border-bottom: 1px solid hsla(222, 27%, 24%, 0.4);
  font-size: 0.92rem;
  transition: background-color 0.15s;
}

.leaderboard-row:last-child {
  border-bottom: none;
}

.leaderboard-row.highlight-me {
  background-color: rgba(139, 92, 246, 0.1);
  border-left: 4px solid var(--color-primary);
  padding-left: 20px;
}

/* Rank column */
.leaderboard-rank {
  font-weight: 800;
  font-size: 0.95rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
}

.leaderboard-rank.top-1 { font-size: 1.35rem; }
.leaderboard-rank.top-2 { font-size: 1.35rem; }
.leaderboard-rank.top-3 { font-size: 1.35rem; }

/* User avatar and name layout */
.leaderboard-user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.leaderboard-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 2px solid var(--border-color);
  object-fit: cover;
  flex-shrink: 0;
  background-color: var(--bg-main);
}

.leaderboard-name {
  font-weight: 700;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.leaderboard-row.highlight-me .leaderboard-name {
  color: var(--color-primary);
}

/* Streak value display */
.leaderboard-streak {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
  font-weight: 800;
  font-size: 0.95rem;
  color: #ff9600;
  text-align: right;
  padding-right: 8px;
}

/* Sticky bottom section */
.leaderboard-sticky-row {
  border-top: 2px solid var(--border-color);
  background: var(--bg-card);
  box-shadow: 0 -4px 15px rgba(0, 0, 0, 0.15);
  flex-shrink: 0;
}

.leaderboard-sticky-row .leaderboard-row {
  border-bottom: none;
  background-color: rgba(139, 92, 246, 0.15);
  padding: 14px 24px;
  border-left: 4px solid var(--color-primary);
  padding-left: 20px;
}

.leaderboard-sticky-label {
  font-size: 0.65rem;
  font-weight: 800;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 8px 24px 0;
  background-color: rgba(139, 92, 246, 0.15);
  display: block;
}

/* ── Multi-deck picker, game modes and dialogs ─────────────────────────── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.tile-option.unavailable {
  opacity: .45;
  cursor: not-allowed;
}

.tile-option.unavailable .tile-label {
  cursor: not-allowed;
}

.deck-picker-trigger {
  width: 100%;
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  color: var(--text-main);
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-bottom-width: 4px;
  border-radius: 16px;
  font-family: inherit;
  text-align: left;
  cursor: pointer;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.deck-picker-trigger:hover,
.deck-picker-trigger[aria-expanded="true"] {
  border-color: var(--color-primary);
}

.deck-picker-trigger:active {
  transform: translateY(2px);
  border-bottom-width: 2px;
}

.deck-picker-icon { font-size: 1.7rem; }
.deck-picker-copy { min-width: 0; display: flex; flex: 1; flex-direction: column; gap: 2px; }
.deck-picker-copy strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: .98rem; }
.deck-picker-copy small, .deck-picker-status { color: var(--text-muted); font-size: .8rem; font-weight: 600; }
.deck-picker-chevron { color: var(--color-primary); font-size: 1.5rem; font-weight: 800; }
.deck-picker-status { min-height: 1.1em; margin-top: 8px; }

.app-modal-overlay {
  position: fixed;
  z-index: 20000;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: rgba(0, 0, 0, .62);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  animation: modal-fade-in .18s ease-out;
}

@keyframes modal-fade-in { from { opacity: 0; } to { opacity: 1; } }

.deck-picker-modal,
.exit-game-modal {
  width: min(560px, 100%);
  max-height: min(760px, calc(100dvh - 32px));
  display: flex;
  flex-direction: column;
  overflow: hidden;
  color: var(--text-main);
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 24px;
  box-shadow: 0 8px 0 var(--border-color), 0 22px 54px rgba(0, 0, 0, .4);
  animation: modal-pop .24s cubic-bezier(.34, 1.56, .64, 1);
}

@keyframes modal-pop { from { opacity: 0; transform: translateY(22px) scale(.96); } to { opacity: 1; transform: none; } }

.picker-modal-header {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 22px 16px;
  border-bottom: 2px solid var(--border-color);
}
.picker-modal-header h2, .exit-game-modal h2 { margin: 0; font-size: 1.35rem; font-weight: 800; }
.picker-modal-header p { margin-top: 5px; color: var(--text-muted); font-size: .9rem; }
.modal-close-btn { width: 44px; height: 44px; border: 0; color: var(--text-muted); background: transparent; font: inherit; font-size: 1.15rem; cursor: pointer; }
.modal-close-btn:hover { color: var(--color-error); }
.picker-modal-body { min-height: 0; overflow-y: auto; padding: 16px 22px; }
.deck-picker-search { width: 100%; min-height: 48px; padding: 0 14px; color: var(--text-main); background: var(--bg-main); border: 2px solid var(--border-color); border-radius: 12px; font-family: inherit; outline: none; }
.deck-picker-search:focus { border-color: var(--color-primary); }
.deck-picker-list { display: flex; flex-direction: column; gap: 18px; margin-top: 18px; }
.deck-picker-group h3 { margin: 0 0 9px; color: var(--text-muted); font-size: .75rem; letter-spacing: .07em; text-transform: uppercase; }
.deck-picker-system-group h3 { color: var(--color-primary); }
.deck-picker-own-group h3 { color: var(--color-secondary); }
.deck-check-row { min-height: 64px; display: flex; align-items: center; gap: 11px; padding: 10px 4px; border-bottom: 1px solid var(--border-color); cursor: pointer; }
.deck-check-row:last-child { border-bottom: 0; }
.deck-check-row input { width: 20px; height: 20px; accent-color: var(--color-primary); flex: 0 0 auto; }
.deck-check-row.disabled { cursor: not-allowed; opacity: .5; }
.deck-check-icon { font-size: 1.2rem; }
.deck-check-copy { min-width: 0; flex: 1; display: flex; flex-direction: column; gap: 2px; }
.deck-check-copy strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.deck-check-copy small { color: var(--text-muted); font-size: .8rem; }
.deck-check-mark { color: var(--color-primary); font-size: 1.1rem; font-weight: 900; }
.deck-picker-empty { display: flex; min-height: 150px; align-items: center; justify-content: center; flex-direction: column; gap: 10px; color: var(--text-muted); text-align: center; }
.deck-picker-empty a { color: var(--color-primary); font-weight: 800; }
.picker-modal-footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 14px 22px; border-top: 2px solid var(--border-color); background: var(--bg-card); }
.deck-picker-count { color: var(--text-muted); font-size: .85rem; font-weight: 800; }
.picker-modal-actions { display: flex; align-items: center; gap: 8px; }
.picker-modal-actions .primary-btn, .picker-modal-actions .secondary-btn { min-height: 42px; padding: 9px 15px; font-size: .9rem; }
.text-btn { min-height: 42px; padding: 7px; color: var(--color-primary); background: transparent; border: 0; font-family: inherit; font-weight: 800; cursor: pointer; }

.exit-game-modal { width: min(390px, 100%); padding: 28px 24px 24px; align-items: center; text-align: center; overflow: visible; }
.exit-game-icon { font-size: 4rem; margin-bottom: 10px; }
.exit-game-modal p { margin: 10px 0 22px; color: var(--text-muted); line-height: 1.45; }
.exit-game-actions { width: 100%; display: grid; gap: 10px; }
.exit-game-actions .primary-btn, .exit-game-actions .danger-outline-btn { width: 100%; min-height: 48px; }
.danger-outline-btn { color: var(--color-error); border: 2px solid var(--color-error-border); border-bottom-width: 4px; border-radius: 14px; background: transparent; font-family: inherit; font-size: 1rem; font-weight: 800; cursor: pointer; }
.danger-outline-btn:active { transform: translateY(2px); border-bottom-width: 2px; }

.word-illustration { position: relative; width: 100%; min-height: 170px; overflow: hidden; border: 2px solid var(--border-color); border-radius: 18px; background: var(--bg-card); }
.word-illustration.loading { display: grid; place-items: center; }
.word-illustration img { display: block; width: 100%; height: 190px; object-fit: cover; }
.image-placeholder { display: grid; min-height: 160px; place-items: center; padding: 20px; color: var(--text-muted); text-align: center; font-weight: 700; }
.image-attribution { display: flex; flex-wrap: wrap; gap: 3px; padding: 8px 10px; color: var(--text-muted); font-size: .68rem; line-height: 1.35; }
.image-attribution a { color: var(--color-primary); }

.speedtype-card, .preview-card { width: 100%; padding: 24px; border: 2px solid var(--border-color); border-radius: 20px; background: var(--bg-card); box-shadow: var(--shadow-card); }
.speedtype-hint { color: var(--text-muted); font-size: .94rem; font-weight: 600; line-height: 1.5; }
.speedtype-input { margin-top: 20px; font-size: 1.25rem; }
.speedtype-input.speedtype-error { border-color: var(--color-error); box-shadow: 0 0 0 3px hsla(350, 85%, 55%, .12); }
.speedtype-input.speedtype-complete { border-color: var(--color-success); color: var(--color-success); }
.speedtype-speech-warning { margin-top: 14px; color: var(--text-muted); font-size: .82rem; font-weight: 600; line-height: 1.45; }
.speedtype-stats { width: 100%; display: flex; justify-content: space-around; gap: 8px; padding: 11px; color: var(--color-accent); font-size: .84rem; font-weight: 800; }
.speedtype-actions { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); width: 100%; gap: 12px; }
.speedtype-actions > button { width: 100%; min-height: 48px; }
.speedtype-actions > :only-child { grid-column: 1 / -1; }
.preview-card { text-align: center; }
.preview-vietnamese { margin-bottom: 20px; color: var(--color-primary); font-size: 1.35rem; font-weight: 800; line-height: 1.4; }
.listen-again-btn { min-height: 44px; padding: 9px 15px; color: var(--color-primary); background: color-mix(in srgb, var(--color-primary) 10%, var(--bg-card)); border: 2px solid var(--color-primary); border-radius: 12px; font-family: inherit; font-weight: 800; cursor: pointer; }
.preview-actions { display: grid; grid-template-columns: 1fr 1fr; width: 100%; gap: 12px; }
.preview-actions .primary-btn, .preview-review-btn { min-height: 50px; padding: 10px; font-size: .9rem; }
.preview-review-btn { color: #be7000; border: 2px solid #ff9600; border-bottom-width: 4px; border-radius: 14px; background: color-mix(in srgb, #ff9600 10%, var(--bg-card)); font-family: inherit; font-weight: 800; cursor: pointer; }

/* Memory flip-card game */
.memory-board { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); width: 100%; gap: 12px; }
.memory-card { position: relative; min-width: 0; min-height: 112px; padding: 0; border: 0; background: transparent; cursor: pointer; perspective: 700px; font-family: inherit; }
.memory-card:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 3px; border-radius: 16px; }
.memory-card-inner { position: absolute; inset: 0; display: block; transform-style: preserve-3d; -webkit-transform-style: preserve-3d; will-change: transform; transition: transform .34s cubic-bezier(.22, .9, .28, 1.15); }
.memory-card.is-open .memory-card-inner, .memory-card.is-matched .memory-card-inner { transform: rotateY(180deg); }
.memory-card-face { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; padding: 10px; border: 2px solid var(--border-color); border-bottom-width: 5px; border-radius: 16px; backface-visibility: hidden; -webkit-backface-visibility: hidden; -webkit-transform: translateZ(.1px); transform: translateZ(.1px); box-shadow: var(--shadow-card); transition: border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast); }
.memory-card-back { color: #fff; background: linear-gradient(145deg, var(--color-primary), var(--color-secondary)); font-size: 1.55rem; }
.memory-card-front { transform: rotateY(180deg) translateZ(.1px); -webkit-transform: rotateY(180deg) translateZ(.1px); color: var(--text-main); background: var(--bg-card); font-weight: 800; line-height: 1.26; text-align: center; overflow-wrap: anywhere; }
.memory-card-english { font-size: .92rem; }
.memory-card-vietnamese { color: var(--text-muted); font-size: .78rem; font-weight: 700; }
.memory-card.is-matched .memory-card-front { color: var(--color-success); border-color: var(--color-success-border); background: var(--color-success-bg); }
.memory-card.is-wrong { animation: shake .4s ease-in-out; }
.memory-card.is-wrong .memory-card-front { color: var(--color-error); border-color: var(--color-error-border); background: var(--color-error-bg); }
.memory-card:disabled { cursor: default; opacity: 1; }
.memory-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); width: 100%; gap: 8px; padding: 11px; color: var(--color-accent); border: 1px solid var(--border-color); border-radius: 13px; background: color-mix(in srgb, var(--bg-card) 88%, var(--color-primary)); font-size: .8rem; font-weight: 800; text-align: center; }
.memory-status { min-height: 1.4em; margin: 3px 0 0; color: var(--text-muted); font-size: .83rem; font-weight: 650; line-height: 1.45; text-align: center; }

/* Fast true/false flashcard swipe game */
.swipe-game { width: 100%; display: grid; justify-items: center; gap: 12px; overflow: hidden; padding: 2px 8px 8px; }
.swipe-timer { width: min(390px, 100%); display: grid; grid-template-columns: minmax(0, 1fr) 48px; align-items: center; gap: 10px; }
.swipe-timer-track { height: 11px; overflow: hidden; border: 1px solid var(--border-color); border-radius: 999px; background: var(--bg-card); }
.swipe-timer-fill { width: 100%; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--color-secondary), var(--color-primary)); transition: width .05s linear, background .2s; }
.swipe-timer.urgent .swipe-timer-fill { background: linear-gradient(90deg, #ff9600, var(--color-error)); }
.swipe-timer-text { color: var(--text-muted); font-size: .78rem; font-weight: 900; font-variant-numeric: tabular-nums; text-align: right; }
.swipe-timer.urgent .swipe-timer-text { color: var(--color-error); }
.swipe-stage { position: relative; width: min(390px, 100%); height: 330px; display: grid; place-items: center; perspective: 900px; }
.swipe-stage::before, .swipe-stage::after { content: ''; position: absolute; width: 88%; height: 88%; border: 2px solid var(--border-color); border-radius: 24px; background: var(--bg-card); box-shadow: var(--shadow-card); }
.swipe-stage::before { transform: translateY(13px) scale(.94) rotate(-2deg); opacity: .4; }
.swipe-stage::after { transform: translateY(7px) scale(.97) rotate(1.3deg); opacity: .7; }
.swipe-card { position: relative; z-index: 2; width: 100%; min-height: 300px; display: flex; align-items: center; justify-content: center; flex-direction: column; overflow: hidden; padding: 32px 24px 24px; color: var(--text-main); border: 2px solid var(--border-color); border-bottom-width: 6px; border-radius: 24px; background: linear-gradient(155deg, color-mix(in srgb, var(--bg-card) 90%, var(--color-primary)), var(--bg-card)); box-shadow: 0 14px 32px rgba(0, 0, 0, .2); cursor: grab; user-select: none; touch-action: none; transition: transform .22s ease, opacity .28s ease, border-color .2s, background .2s; }
.swipe-card.dragging { cursor: grabbing; transition: border-color .2s, background .2s; }
.swipe-card.snap-back { transition: transform .22s cubic-bezier(.22, .9, .28, 1.2); }
.swipe-card:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 4px; }
.swipe-card-kicker { color: var(--text-muted); font-size: .68rem; font-weight: 900; letter-spacing: .12em; }
.swipe-card-english { max-width: 100%; margin-top: 6px; font-size: clamp(1.7rem, 7vw, 2.55rem); font-weight: 900; line-height: 1.15; overflow-wrap: anywhere; text-align: center; }
.swipe-card-divider { width: 54px; height: 4px; margin: 22px 0; border-radius: 999px; background: linear-gradient(90deg, var(--color-secondary), var(--color-primary)); }
.swipe-card-vietnamese { max-width: 100%; margin-top: 7px; color: var(--color-primary); font-size: clamp(1.08rem, 4vw, 1.42rem); font-weight: 800; line-height: 1.35; overflow-wrap: anywhere; text-align: center; }
.swipe-card-hint { margin-top: auto; padding-top: 23px; color: var(--text-muted); font-size: .72rem; font-weight: 700; }
.swipe-verdict { position: absolute; z-index: 3; top: 20px; padding: 7px 11px; border: 3px solid currentColor; border-radius: 10px; font-size: 1.05rem; font-weight: 950; letter-spacing: .08em; opacity: 0; transition: opacity .12s, transform .12s; }
.swipe-verdict-left { left: 18px; color: var(--color-error); transform: rotate(-10deg) scale(.75); }
.swipe-verdict-right { right: 18px; color: var(--color-success); transform: rotate(10deg) scale(.75); }
.swipe-card.lean-left .swipe-verdict-left, .swipe-card.lean-right .swipe-verdict-right { opacity: 1; transform: rotate(0) scale(1); }
.swipe-card.lean-left { border-color: var(--color-error-border); background: color-mix(in srgb, var(--color-error-bg) 45%, var(--bg-card)); }
.swipe-card.lean-right { border-color: var(--color-success-border); background: color-mix(in srgb, var(--color-success-bg) 45%, var(--bg-card)); }
.swipe-card.swipe-answer-correct { border-color: var(--color-success-border); box-shadow: 0 14px 32px color-mix(in srgb, var(--color-success) 22%, transparent); }
.swipe-card.swipe-answer-wrong { border-color: var(--color-error-border); }
.swipe-card.swipe-timeout { transform: scale(.96); opacity: .58; animation: shake .38s ease-in-out; }
.swipe-actions { width: min(390px, 100%); display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.swipe-action { min-height: 52px; padding: 10px 16px; border: 2px solid; border-bottom-width: 5px; border-radius: 16px; background: var(--bg-card); font: inherit; font-size: 1rem; font-weight: 900; cursor: pointer; }
.swipe-action:active { transform: translateY(3px); border-bottom-width: 2px; }
.swipe-action:disabled { cursor: default; opacity: .55; }
.swipe-action-wrong { color: var(--color-error); border-color: var(--color-error-border); background: color-mix(in srgb, var(--color-error-bg) 55%, var(--bg-card)); }
.swipe-action-right { color: var(--color-success); border-color: var(--color-success-border); background: color-mix(in srgb, var(--color-success-bg) 55%, var(--bg-card)); }
.swipe-stats { width: min(390px, 100%); display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; color: var(--text-muted); font-size: .76rem; font-weight: 850; text-align: center; }
.swipe-status { width: 100%; min-height: 1.4em; margin: 0; color: var(--text-muted); font-size: .8rem; font-weight: 700; text-align: center; }

@media (max-width: 520px) {
  .app-modal-overlay { align-items: flex-end; padding: 0; }
  .deck-picker-modal { width: 100%; max-height: 86dvh; border-radius: 24px 24px 0 0; border-bottom: 0; }
  .picker-modal-header, .picker-modal-body, .picker-modal-footer { padding-left: 16px; padding-right: 16px; }
  .picker-modal-footer { align-items: flex-start; flex-direction: column; }
  .picker-modal-actions { width: 100%; }
  .picker-modal-actions .primary-btn, .picker-modal-actions .secondary-btn { flex: 1; }
  .text-btn { margin-right: auto; }
  .exit-game-modal { margin: auto 16px; }
  .preview-actions { grid-template-columns: 1fr; }
  .speedtype-actions { grid-template-columns: 1fr; }
  .memory-board { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 9px; }
  .memory-card { min-height: 102px; }
  .memory-card-face { padding: 8px; border-radius: 14px; }
  .memory-card-english { font-size: .82rem; }
  .memory-card-vietnamese { font-size: .7rem; }
  .memory-stats { padding: 9px 6px; font-size: .72rem; }
  .swipe-stage { height: 305px; }
  .swipe-card { min-height: 278px; padding: 28px 18px 20px; border-radius: 20px; }
  .swipe-card-divider { margin: 17px 0; }
  .swipe-card-hint { padding-top: 18px; }
  .swipe-action { min-height: 50px; }
}

@media (max-width: 360px) {
  .memory-board { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .memory-card { min-height: 106px; }
}

/* System deck picker and vocabulary mindmap */
.deck-check-row { gap: 8px; cursor: default; }
.deck-check-select { min-width: 0; flex: 1; min-height: 48px; display: flex; align-items: center; gap: 11px; cursor: pointer; }
.deck-check-row.disabled .deck-check-select { cursor: not-allowed; }
.deck-mindmap-btn { flex: 0 0 auto; min-height: 40px; padding: 7px 9px; color: var(--color-primary); border: 1.5px solid color-mix(in srgb, var(--color-primary) 46%, var(--border-color)); border-radius: 10px; background: color-mix(in srgb, var(--color-primary) 8%, var(--bg-card)); font: inherit; font-size: .72rem; font-weight: 800; cursor: pointer; }
.deck-mindmap-btn:hover { background: var(--color-primary); color: #fff; }
.deck-mindmap-view { display: flex; min-height: 0; flex-direction: column; gap: 10px; }
.mindmap-toolbar { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr) minmax(0, 1fr); align-items: center; gap: 8px; }
.mindmap-toolbar .text-btn { justify-self: start; }
.mindmap-title { min-width: 0; margin: 0; overflow: hidden; color: var(--text-main); font-size: .9rem; font-weight: 900; text-align: center; text-overflow: ellipsis; white-space: nowrap; outline: none; }
.mindmap-zoom-controls { display: flex; justify-content: flex-end; gap: 4px; }
.mindmap-zoom-controls button { width: 32px; height: 32px; padding: 0; color: var(--text-main); border: 1.5px solid var(--border-color); border-radius: 9px; background: var(--bg-main); font: inherit; font-weight: 900; cursor: pointer; }
.mindmap-status { min-height: 1.2em; margin: 0; color: var(--text-muted); font-size: .75rem; font-weight: 600; text-align: center; }
.deck-mindmap-viewport { position: relative; min-height: 420px; overflow: hidden; border: 2px solid var(--border-color); border-radius: 18px; background: radial-gradient(circle at 50% 50%, color-mix(in srgb, var(--color-primary) 14%, var(--bg-card)), var(--bg-main) 70%); cursor: grab; touch-action: none; }
.deck-mindmap-viewport.dragging { cursor: grabbing; }
.deck-mindmap-scene { position: absolute; top: calc(50% - 340px); left: calc(50% - 460px); width: 920px; height: 680px; transform-origin: center center; will-change: transform; }
.mindmap-lines { position: absolute; z-index: 1; inset: 0; width: 920px; height: 680px; overflow: visible; }
.mindmap-lines path { fill: none; stroke: color-mix(in srgb, var(--color-primary) 46%, var(--border-color)); stroke-width: 2.5; stroke-linecap: round; opacity: .72; }
.mindmap-root, .mindmap-word-node { position: absolute; display: flex; flex-direction: column; align-items: center; justify-content: center; transform: translate(-50%, -50%); text-align: center; }
.mindmap-root { z-index: 3; width: 164px; min-height: 108px; padding: 13px 15px; color: #fff; border: 3px solid rgba(255,255,255,.62); border-radius: 30px; background: linear-gradient(145deg, var(--color-primary), var(--color-secondary)); box-shadow: 0 10px 24px color-mix(in srgb, var(--color-primary) 40%, transparent); }
.mindmap-root strong { display: -webkit-box; overflow: hidden; font-size: .9rem; line-height: 1.22; -webkit-line-clamp: 3; -webkit-box-orient: vertical; }
.mindmap-root small { margin-top: 4px; font-size: .68rem; font-weight: 700; opacity: .86; }
.mindmap-word-node { z-index: 2; width: 144px; min-height: 86px; padding: 9px 11px; color: var(--text-main); border: 2px solid color-mix(in srgb, var(--color-primary) 36%, var(--border-color)); border-radius: 16px; background: color-mix(in srgb, var(--bg-card) 92%, var(--color-primary)); box-shadow: 0 5px 0 color-mix(in srgb, var(--border-color) 76%, var(--color-primary)); }
.mindmap-word-node:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 4px; }
.mindmap-word-node strong { display: -webkit-box; width: 100%; overflow: hidden; font-size: .84rem; font-weight: 900; line-height: 1.18; overflow-wrap: anywhere; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.mindmap-word-node small { display: -webkit-box; width: 100%; overflow: hidden; margin-top: 5px; padding-top: 4px; color: var(--text-muted); border-top: 1px solid color-mix(in srgb, var(--border-color) 76%, var(--color-primary)); font-size: .7rem; font-weight: 700; line-height: 1.2; overflow-wrap: anywhere; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.mindmap-pagination { display: flex; min-height: 42px; align-items: center; justify-content: center; gap: 10px; color: var(--text-muted); font-size: .8rem; font-weight: 800; }
.mindmap-pagination .secondary-btn { min-height: 38px; padding: 6px 10px; font-size: .78rem; }

@media (min-width: 521px) {
  .deck-picker-modal { width: min(980px, calc(100vw - 48px)); max-height: min(920px, calc(100dvh - 24px)); }
  .deck-mindmap-viewport { height: clamp(490px, 61vh, 620px); min-height: 490px; }
}

/* Preview example sentences */
.preview-tools { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.preview-example-btn { min-height: 44px; padding: 9px 15px; color: var(--text-main); border: 2px solid var(--border-color); border-radius: 12px; background: var(--bg-main); font: inherit; font-weight: 800; cursor: pointer; }
.preview-example-btn:hover { border-color: var(--color-secondary); color: var(--color-secondary); }
.preview-example-btn:disabled { opacity: .64; cursor: wait; }
.preview-examples { margin-top: 16px; text-align: left; }
.preview-example-list { display: grid; gap: 8px; }
.preview-example-row { padding: 10px 12px; border: 1.5px solid var(--border-color); border-radius: 12px; background: var(--bg-main); }
.preview-example-row strong, .preview-example-row small { display: block; }
.preview-example-row strong { color: var(--text-main); font-size: .88rem; line-height: 1.4; }
.preview-example-row small { margin-top: 4px; color: var(--text-muted); font-size: .8rem; line-height: 1.4; }
.preview-example-empty, .preview-example-loading { margin: 6px 0; color: var(--text-muted); font-size: .83rem; font-weight: 600; line-height: 1.45; text-align: center; }
.preview-example-source { margin: 10px 0 0; color: var(--text-muted); font-size: .7rem; text-align: center; }
.preview-example-source a { color: var(--color-primary); font-weight: 800; }

/* AI conversation/tutor mode */
.ai-chat-mode-grid { display: grid; gap: 12px; }
.ai-chat-mode-card { min-height: 94px; display: flex; flex-direction: column; justify-content: center; gap: 5px; padding: 15px; color: var(--text-main); border: 2px solid var(--border-color); border-radius: 16px; background: var(--bg-main); box-shadow: 0 4px 0 var(--border-color); font: inherit; text-align: left; cursor: pointer; transition: transform .15s, border-color .15s; }
.ai-chat-mode-card strong { font-size: .95rem; }
.ai-chat-mode-card small { color: var(--text-muted); font-size: .78rem; font-weight: 600; line-height: 1.4; }
.ai-chat-mode-card:hover { transform: translateY(-2px); border-color: var(--color-primary); }
.ai-chat-tutor-suggestions { display: flex; flex-wrap: wrap; gap: 8px; }
.ai-chat-tutor-suggestions button { min-height: 38px; padding: 7px 10px; color: var(--color-primary); border: 1.5px solid color-mix(in srgb, var(--color-primary) 40%, var(--border-color)); border-radius: 999px; background: color-mix(in srgb, var(--color-primary) 7%, var(--bg-card)); font: inherit; font-size: .76rem; font-weight: 700; cursor: pointer; }
.ai-chat-input-bar textarea { flex: 1; min-height: 44px; max-height: 110px; resize: none; overflow-y: auto; padding: 10px 14px; color: var(--text-main); border: 2px solid var(--border-color); border-radius: 14px; background: var(--bg-main); font-family: var(--font-family); font-size: .88rem; line-height: 1.35; outline: none; }
.ai-chat-input-bar textarea:focus { border-color: var(--color-primary); }
.ai-chat-input-bar textarea::placeholder { color: var(--text-muted); }
.ai-chat-bubble, .ai-chat-translation { white-space: pre-wrap; }
.ai-chat-message-actions { display: flex; gap: 7px; }
.ai-chat-user-wrapper { align-self: flex-end; }
.ai-chat-message-actions button { padding: 2px 4px; color: var(--text-muted); border: 0; background: transparent; font: inherit; font-size: .72rem; font-weight: 700; cursor: pointer; }
.ai-chat-retry-btn { align-self: flex-start; min-height: 34px; padding: 5px 9px; color: var(--color-primary); border: 1.5px solid var(--color-primary); border-radius: 9px; background: transparent; font: inherit; font-size: .76rem; font-weight: 800; cursor: pointer; }

@media (max-width: 520px) {
  .deck-mindmap-viewport { min-height: 365px; }
  .mindmap-toolbar { grid-template-columns: 1fr auto; }
  .mindmap-title { grid-column: 1 / -1; grid-row: 1; }
  .mindmap-toolbar .text-btn { grid-row: 2; }
  .mindmap-zoom-controls { grid-column: 2; grid-row: 2; }
  .mindmap-root { width: 156px; min-height: 102px; }
  .mindmap-word-node { width: 140px; min-height: 84px; }
}

/* Speak & score: a self-contained microphone workspace. */
.speak-workspace { width: min(100%, 530px); display: grid; justify-items: center; gap: 14px; padding: 22px 18px 18px; border: 2px solid var(--border-color); border-radius: 22px; background: linear-gradient(145deg, color-mix(in srgb, var(--color-primary) 10%, var(--bg-card)), var(--bg-card) 56%); box-shadow: var(--shadow-card); text-align: center; }
.speak-lead { max-width: 390px; margin: 0; color: var(--text-muted); font-size: .88rem; font-weight: 650; line-height: 1.5; }
.speak-recording-timer { width: min(100%, 280px); position: relative; overflow: hidden; padding: 9px 14px; color: var(--text-main); border: 1.5px solid var(--border-color); border-radius: 999px; background: var(--bg-main); font-size: .84rem; font-weight: 800; isolation: isolate; }
.speak-recording-timer::before { position: absolute; z-index: -1; top: 0; bottom: 0; left: 0; width: var(--recording-progress, 0%); content: ''; background: color-mix(in srgb, var(--color-primary) 17%, transparent); transition: width .1s linear; }
.speak-actions { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(108px, .65fr); width: 100%; gap: 10px; }
.speak-login-btn { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; padding: 10px 16px; font-size: .88rem; text-decoration: none; }
.speak-record-btn { min-height: 52px; padding: 10px 14px; color: #fff; border: 2px solid var(--color-primary); border-bottom-width: 5px; border-radius: 15px; background: linear-gradient(135deg, var(--color-primary), var(--color-secondary)); box-shadow: 0 6px 17px color-mix(in srgb, var(--color-primary) 28%, transparent); font: inherit; font-size: .9rem; font-weight: 900; cursor: pointer; transition: transform .15s ease, filter .15s ease; }
.speak-record-btn:hover:not(:disabled) { filter: brightness(1.05); transform: translateY(-1px); }
.speak-record-btn:active:not(:disabled) { transform: translateY(2px); border-bottom-width: 3px; }
.speak-record-btn.is-recording { border-color: #f04d63; background: linear-gradient(135deg, #ef4660, #fc7a5d); animation: speak-pulse 1.15s ease-in-out infinite; }
.speak-record-btn:disabled, .speak-skip-btn:disabled { cursor: not-allowed; opacity: .62; }
.speak-skip-btn { min-height: 52px; padding: 8px 12px; font-size: .9rem; }
.speak-status { min-height: 1.45em; margin: 0; color: var(--text-muted); font-size: .83rem; font-weight: 700; line-height: 1.45; }
.speak-status[data-tone="recording"] { color: #d84b5d; }
.speak-status[data-tone="success"] { color: var(--color-success); }
.speak-status[data-tone="error"] { color: var(--color-error); }
.speak-outcome { display: grid; width: 100%; gap: 7px; }
.speak-transcript, .speak-score { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin: 0; padding: 10px 12px; border: 1.5px solid var(--border-color); border-radius: 12px; background: var(--bg-main); color: var(--text-muted); font-size: .82rem; text-align: left; }
.speak-transcript strong { min-width: 0; overflow-wrap: anywhere; color: var(--text-main); font-size: .91rem; }
.speak-outcome-label { flex: 0 0 auto; font-weight: 700; }
.speak-score strong { color: var(--color-primary); font-size: 1rem; }
.speak-score.passed { border-color: var(--color-success-border); background: var(--color-success-bg); }
.speak-score.passed strong { color: var(--color-success); }
.speak-quota { color: var(--text-muted); font-size: .72rem; font-weight: 650; }
.speak-workspace.is-busy .speak-recording-timer { border-color: color-mix(in srgb, var(--color-primary) 55%, var(--border-color)); }
@keyframes speak-pulse { 50% { box-shadow: 0 0 0 8px color-mix(in srgb, #ef4660 18%, transparent), 0 8px 21px color-mix(in srgb, #ef4660 28%, transparent); } }
@media (prefers-reduced-motion: reduce) { .speak-record-btn.is-recording { animation: none; } }
@media (max-width: 420px) { .speak-workspace { padding: 18px 13px 15px; border-radius: 18px; } .speak-actions { grid-template-columns: 1fr; } .speak-actions > button { width: 100%; } }

/* Custom stage picker and falling-word Speedtype. */
.custom-mode-summary-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 13px; }
.custom-mode-summary { min-width: 0; margin: 0; color: var(--text-muted); font-size: .8rem; font-weight: 700; line-height: 1.4; }
.custom-mode-config { min-height: 42px; flex: 0 0 auto; padding: 8px 12px; font-size: .8rem; }
.custom-mode-modal { width: min(540px, 100%); max-height: min(710px, calc(100dvh - 32px)); display: flex; flex-direction: column; overflow: hidden; color: var(--text-main); border: 2px solid var(--border-color); border-radius: 24px; background: var(--bg-card); box-shadow: 0 8px 0 var(--border-color), 0 22px 54px rgba(0,0,0,.4); animation: modal-pop .24s cubic-bezier(.34, 1.56, .64, 1); }
.custom-mode-list { display: grid; min-height: 0; gap: 7px; overflow-y: auto; padding: 15px 22px; }
.custom-mode-row { min-height: 58px; display: flex; align-items: center; gap: 12px; padding: 9px 11px; border: 1.5px solid var(--border-color); border-radius: 14px; background: var(--bg-main); cursor: pointer; }
.custom-mode-row:has(input:checked) { border-color: var(--color-primary); background: color-mix(in srgb, var(--color-primary) 8%, var(--bg-card)); }
.custom-mode-row.unavailable { opacity: .68; }
.custom-mode-row input { width: 20px; height: 20px; flex: 0 0 auto; accent-color: var(--color-primary); }
.custom-mode-copy { min-width: 0; display: grid; gap: 2px; }
.custom-mode-copy strong { color: var(--text-main); font-size: .9rem; }
.custom-mode-copy small { color: var(--text-muted); font-size: .74rem; font-weight: 650; }
.custom-result-breakdown { grid-column: 1 / -1; margin: 2px 0 0; color: var(--text-muted); font-size: .78rem; font-weight: 700; line-height: 1.45; text-align: center; }

.speed-fall-game { width: 100%; display: grid; gap: 12px; }
.speed-fall-arena { position: relative; width: 100%; min-height: clamp(360px, 51vh, 510px); overflow: hidden; border: 2px solid color-mix(in srgb, var(--color-primary) 44%, var(--border-color)); border-radius: 24px; background: radial-gradient(ellipse at 50% -22%, color-mix(in srgb, var(--color-secondary) 28%, transparent), transparent 54%), linear-gradient(180deg, color-mix(in srgb, var(--bg-card) 74%, var(--color-primary)), var(--bg-main)); box-shadow: inset 0 -25px 38px color-mix(in srgb, var(--color-primary) 9%, transparent), var(--shadow-card); }
.speed-fall-grid { position: absolute; inset: 0; pointer-events: none; opacity: .33; background-image: linear-gradient(90deg, transparent calc(33.333% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) calc(33.333% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) 33.333%, transparent 33.333%, transparent calc(66.666% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) calc(66.666% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) 66.666%, transparent 66.666%); }
.speed-danger-line { position: absolute; z-index: 3; right: 12px; bottom: 74px; left: 12px; height: 3px; display: flex; align-items: center; justify-content: center; color: var(--color-error); border-radius: 999px; background: linear-gradient(90deg, transparent, var(--color-error) 11%, var(--color-error) 89%, transparent); box-shadow: 0 0 12px color-mix(in srgb, var(--color-error) 52%, transparent); font-size: .62rem; font-weight: 950; letter-spacing: .13em; text-shadow: 0 1px var(--bg-card); }
.falling-word-card { position: absolute; z-index: 2; top: 0; width: min(29%, 220px); min-height: 78px; display: flex; align-items: center; justify-content: center; flex-direction: column; gap: 5px; padding: 10px 12px; color: var(--text-main); border: 2px solid color-mix(in srgb, var(--color-primary) 45%, var(--border-color)); border-bottom-width: 5px; border-radius: 17px; background: color-mix(in srgb, var(--bg-card) 92%, var(--color-primary)); box-shadow: 0 8px 22px color-mix(in srgb, var(--color-primary) calc(var(--fall-glow, .2) * 55%), transparent); text-align: center; will-change: transform, opacity; }
.falling-word-vietnamese { width: 100%; overflow: hidden; font-size: clamp(.88rem, 2.3vw, 1.05rem); font-weight: 950; line-height: 1.17; overflow-wrap: anywhere; }
.falling-word-english { width: 100%; overflow: hidden; color: var(--text-muted); font-size: clamp(.68rem, 1.7vw, .78rem); font-weight: 700; line-height: 1.2; overflow-wrap: anywhere; }
.falling-word-cleared { pointer-events: none; border-color: var(--color-success-border); background: var(--color-success-bg); animation: falling-burst .36s ease-out forwards; }
.falling-word-missed { pointer-events: none; border-color: var(--color-error-border); background: var(--color-error-bg); animation: falling-miss .36s ease-out forwards; }
.falling-word-skipped { pointer-events: none; opacity: .45; animation: falling-skip .36s ease-out forwards; }
@keyframes falling-burst { 0% { opacity: 1; filter: brightness(1); } 55% { opacity: 1; filter: brightness(1.35) saturate(1.25); } 100% { opacity: 0; filter: brightness(1.55) saturate(1.5); } }
@keyframes falling-miss { to { opacity: 0; filter: saturate(.4); } }
@keyframes falling-skip { to { opacity: 0; filter: grayscale(.45); } }
.speed-input-dock { position: relative; z-index: 4; margin-top: -48px; padding: 0 18px; }
.speed-fall-input { width: 100%; min-height: 56px; margin: 0; border-width: 2px 2px 5px; border-color: var(--color-primary); border-radius: 16px; background: var(--bg-card); box-shadow: 0 8px 24px color-mix(in srgb, var(--color-primary) 16%, transparent); font-size: max(16px, 1.16rem); font-weight: 750; }
.speedtype-stats { flex-wrap: wrap; }
@media (prefers-reduced-motion: reduce) { .falling-word-cleared, .falling-word-missed, .falling-word-skipped { animation: none; opacity: 0; } }
@media (max-width: 520px) {
  .custom-mode-modal { width: 100%; max-height: 86dvh; border-radius: 24px 24px 0 0; border-bottom: 0; }
  .custom-mode-list { padding-right: 16px; padding-left: 16px; }
  .custom-mode-summary-row { align-items: flex-start; flex-direction: column; }
  .custom-mode-config { width: 100%; }
  .speed-fall-arena { min-height: 385px; border-radius: 19px; }
  .speed-fall-grid { background-image: linear-gradient(90deg, transparent calc(50% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) calc(50% - 1px), color-mix(in srgb, var(--border-color) 74%, transparent) 50%, transparent 50%); }
  .falling-word-card { width: min(43%, 182px); min-height: 74px; padding: 9px 8px; }
  .speed-input-dock { padding: 0 11px; }
  .infinite-stop-btn { padding-inline: 8px; font-size: .7rem; }
}

@media (prefers-reduced-motion: reduce) {
  .memory-card-inner { transition: none; }
  .memory-card.is-wrong { animation: none; }
}

/* Separate quiz configuration and answer feedback. */
.learning-tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin: 20px 0 14px; padding: 5px; border-radius: 15px; background: var(--bg-secondary); }
.learning-tab { border: 0; border-radius: 11px; padding: 11px 8px; color: var(--text-secondary); background: transparent; font: inherit; font-weight: 800; cursor: pointer; }
.learning-tab.active { color: var(--text-primary); background: var(--bg-card); box-shadow: 0 2px 6px rgba(0,0,0,.11); }
.choice-card.correct-answer { border-color: var(--color-success); background: var(--color-success-bg); color: var(--color-success-text); }
.choice-card.wrong-answer { border-color: var(--color-error); background: var(--color-error-bg); color: var(--color-error-text); }
.review-explanation { margin-top: 4px; color: var(--text-secondary); font-size: .88rem; white-space: pre-wrap; }
@media (max-width: 480px) { .learning-tab { font-size: .83rem; padding: 10px 4px; } }