/* style.css - TalkFill CSS Design System */

/* ==========================================
   1. Design Tokens & CSS Variables
   ========================================== */
:root {
  /* Fonts */
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-circle: 50%;
}

/* Dark Theme (Default) Tokens */
.dark-theme {
  --bg-app: #080a0f;
  --bg-sub: #10121a;
  --card-bg-rgb: 24, 27, 38;
  --card-bg: rgba(var(--card-bg-rgb), 0.7);
  --card-bg-hover: rgba(var(--card-bg-rgb), 0.95);
  --border-color: rgba(255, 255, 255, 0.07);
  --border-color-hover: rgba(255, 255, 255, 0.15);
  
  /* Text Colors */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  /* Accent Colors */
  --primary-gradient: linear-gradient(135deg, #7c3aed 0%, #06b6d4 100%);
  --primary-color: #8b5cf6;
  --primary-color-rgb: 139, 92, 246;
  --accent-light: #22d3ee;
  
  /* System States */
  --color-success: #10b981;
  --color-success-bg: rgba(16, 185, 129, 0.12);
  --color-warning: #f59e0b;
  --color-warning-bg: rgba(245, 158, 11, 0.12);
  --color-danger: #ef4444;
  --color-danger-bg: rgba(239, 68, 68, 0.12);

  /* Shadows */
  --shadow-main: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 15px rgba(139, 92, 246, 0.35);
  --shadow-success-glow: 0 0 15px rgba(16, 185, 129, 0.3);
  --shadow-warning-glow: 0 0 15px rgba(245, 158, 11, 0.3);
}

/* Light Theme Tokens */
.light-theme {
  --bg-app: #f4f7fa;
  --bg-sub: #e2e8f0;
  --card-bg-rgb: 255, 255, 255;
  --card-bg: rgba(var(--card-bg-rgb), 0.85);
  --card-bg-hover: rgba(var(--card-bg-rgb), 0.98);
  --border-color: rgba(0, 0, 0, 0.08);
  --border-color-hover: rgba(0, 0, 0, 0.15);
  
  /* Text Colors */
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  
  /* Accent Colors */
  --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #0891b2 100%);
  --primary-color: #4f46e5;
  --primary-color-rgb: 79, 70, 229;
  --accent-light: #0891b2;
  
  /* System States */
  --color-success: #059669;
  --color-success-bg: rgba(5, 150, 105, 0.08);
  --color-warning: #d97706;
  --color-warning-bg: rgba(217, 119, 6, 0.08);
  --color-danger: #dc2626;
  --color-danger-bg: rgba(220, 38, 38, 0.08);

  /* Shadows */
  --shadow-main: 0 8px 32px 0 rgba(31, 38, 135, 0.06);
  --shadow-glow: 0 0 15px rgba(79, 70, 229, 0.15);
  --shadow-success-glow: 0 0 15px rgba(5, 150, 105, 0.15);
  --shadow-warning-glow: 0 0 15px rgba(217, 119, 6, 0.15);
}

/* ==========================================
   2. Reset & Global Styles
   ========================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-color: var(--bg-app);
  color: var(--text-primary);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
  min-height: 100vh;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  outline: none;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-app);
}
::-webkit-scrollbar-thumb {
  background: var(--border-color-hover);
  border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Glassmorphism utility */
.glass {
  background: var(--card-bg);
  backdrop-filter: blur(14px) saturate(180%);
  -webkit-backdrop-filter: blur(14px) saturate(180%);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-main);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
}

/* Hide helper */
.hidden {
  display: none !important;
}

/* ==========================================
   3. Layout Grid & Structure
   ========================================== */
.app-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  cursor: pointer;
  user-select: none;
}

.header-logo .logo-text span {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-btn {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-fast);
}

.nav-btn:hover {
  color: var(--text-primary);
  background: rgba(var(--primary-color-rgb), 0.08);
}

.nav-btn.active {
  color: var(--text-primary);
  background: rgba(var(--primary-color-rgb), 0.15);
  font-weight: 600;
}

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

.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.app-footer {
  padding: 32px 0;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 48px;
}

/* ==========================================
   4. Screen Common Styles
   ========================================== */
.app-screen {
  animation: screenFadeUp var(--transition-normal) forwards;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

@keyframes screenFadeUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ==========================================
   5. Dashboard Elements
   ========================================== */
.dashboard-hero {
  padding: 40px 0 20px 0;
  max-width: 720px;
}

.dashboard-hero h1 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
}

.dashboard-hero h1 span {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.dashboard-hero p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Difficulty Card */
.difficulty-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
}

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

.diff-option {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.diff-option:hover {
  background: rgba(255, 255, 255, 0.03);
  border-color: var(--border-color-hover);
}

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

.diff-option.active {
  border-color: var(--primary-color);
  background: rgba(var(--primary-color-rgb), 0.05);
}

.diff-info {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.diff-badge {
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.diff-badge.beginner {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.diff-badge.intermediate {
  background: rgba(139, 92, 246, 0.15);
  color: #a78bfa;
  border: 1px solid rgba(139, 92, 246, 0.3);
}

.diff-badge.advanced {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.diff-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* Preset Scenarios */
.presets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 16px;
}

.preset-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 200px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.preset-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--primary-gradient);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

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

.preset-card:hover::before {
  opacity: 1;
}

.preset-icon {
  font-size: 1.8rem;
  margin-bottom: 12px;
}

.preset-info h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.preset-info p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.preset-action {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-light);
  display: flex;
  align-items: center;
  gap: 4px;
  margin-top: 12px;
}

.preset-action svg {
  transition: transform var(--transition-fast);
}

.preset-card:hover .preset-action svg {
  transform: translateX(4px);
}

/* Custom Card */
.custom-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 28px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.custom-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}

.custom-title-group h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.custom-title-group p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.ai-badge {
  background: linear-gradient(135deg, #db2777 0%, #7c3aed 100%);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: 0 0 10px rgba(124, 58, 237, 0.4);
}

.custom-input-group {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.custom-input-group textarea {
  width: 100%;
  height: 100px;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 14px;
  color: var(--text-primary);
  font-size: 0.95rem;
  resize: none;
  outline: none;
  transition: all var(--transition-fast);
}

.custom-input-group textarea:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 1px var(--primary-color);
  background: rgba(0, 0, 0, 0.3);
}

/* ==========================================
   6. Buttons & Inputs
   ========================================== */
.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff;
  padding: 12px 24px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 15px rgba(var(--primary-color-rgb), 0.3);
}

.btn-primary:hover {
  opacity: 0.95;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(var(--primary-color-rgb), 0.4);
}

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

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 12px 24px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-color-hover);
}

.btn-sm {
  padding: 6px 12px;
  font-size: 0.85rem;
}

.btn-text {
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

.danger-hover:hover {
  background: var(--color-danger-bg);
  border-color: var(--color-danger);
  color: var(--color-danger);
}

/* ==========================================
   7. Practice Interface (Chat & Dialogue)
   ========================================== */
.practice-header {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
}

.practice-title-group h2 {
  font-family: var(--font-heading);
  font-size: 1.7rem;
  font-weight: 800;
  margin-top: 8px;
}

.practice-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.practice-controls-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 8px;
}

.level-indicator {
  font-size: 0.9rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Dialogue Container */
.dialogue-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 24px 0;
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
}

/* Bubble Design */
.bubble-row {
  display: flex;
  gap: 12px;
  width: 100%;
  animation: bubbleFadeIn 0.4s ease forwards;
}

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

.bubble-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-circle);
  background: var(--primary-gradient);
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: 700;
  color: #fff;
  font-size: 0.9rem;
  flex-shrink: 0;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.bubble-row.speaker-alt .bubble-avatar {
  background: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
}

.bubble-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.bubble-speaker {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.bubble-box {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 16px 20px;
  border-radius: 0 var(--radius-md) var(--radius-md) var(--radius-md);
  position: relative;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.bubble-row.speaker-alt .bubble-box {
  border-color: rgba(6, 182, 212, 0.2);
}

/* Speech Text with Blanks */
.speech-text {
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--text-primary);
  display: inline-block;
}

/* Inputs within text */
.blank-input {
  border: none;
  border-bottom: 2px solid var(--text-secondary);
  background: transparent;
  color: var(--accent-light);
  font-weight: 600;
  font-size: 1.05rem;
  text-align: center;
  border-radius: 0;
  outline: none;
  padding: 0px 4px;
  margin: 0 4px;
  transition: all var(--transition-fast);
  min-width: 80px;
}

.blank-input:focus {
  border-bottom-color: var(--primary-color);
  box-shadow: 0 4px 6px -4px rgba(var(--primary-color-rgb), 0.4);
  background: rgba(var(--primary-color-rgb), 0.04);
}

/* Input feedback classes */
.blank-input.correct {
  border-bottom-color: var(--color-success) !important;
  color: var(--color-success) !important;
  background: var(--color-success-bg) !important;
  box-shadow: var(--shadow-success-glow);
}

.blank-input.incorrect {
  border-bottom-color: var(--color-warning) !important;
  color: var(--color-warning) !important;
  background: var(--color-warning-bg) !important;
  box-shadow: var(--shadow-warning-glow);
  animation: shake 0.3s ease;
}

.blank-input.revealed {
  border-bottom-color: var(--primary-color) !important;
  color: var(--primary-color) !important;
  background: rgba(var(--primary-color-rgb), 0.08) !important;
}

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

/* Hint text & toggle */
.bubble-help-block {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--border-color);
}

.korean-translation {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 400;
  flex: 1;
}

.bubble-actions-row {
  display: flex;
  gap: 8px;
  align-items: center;
}

.btn-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: center;
  align-items: center;
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.02);
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.06);
  border-color: var(--border-color-hover);
}

.btn-icon.active {
  color: var(--primary-color);
  border-color: var(--primary-color);
  background: rgba(var(--primary-color-rgb), 0.1);
}

.clue-box {
  background: var(--bg-sub);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--accent-light);
  border-left: 3px solid var(--primary-color);
}

/* Practice Footer Status Bar */
.practice-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  padding: 24px 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.progress-bar-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.progress-track {
  width: 100%;
  height: 8px;
  background: var(--bg-sub);
  border-radius: 9999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--primary-gradient);
  border-radius: 9999px;
  transition: width var(--transition-normal);
}

.action-buttons-group {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

/* ==========================================
   8. Results Screen
   ========================================== */
.result-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 40px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 600px;
  margin: 0 auto;
  width: 100%;
}

.result-score-ring {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 120px;
  height: 120px;
}

.score-circle {
  transform: rotate(-90deg);
}

.score-circle-bg {
  fill: transparent;
  stroke: var(--bg-sub);
  stroke-width: 8;
}

.score-circle-bar {
  fill: transparent;
  stroke: var(--primary-color);
  stroke-width: 8;
  stroke-dasharray: 314.16; /* 2 * PI * r (r=50) */
  stroke-dashoffset: 314.16;
  stroke-linecap: round;
  transition: stroke-dashoffset 0.8s ease-out;
}

.score-text {
  position: absolute;
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 800;
}

.result-card h2 {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 800;
  margin-top: 10px;
}

.result-card p {
  color: var(--text-secondary);
  line-height: 1.5;
  font-size: 0.95rem;
}

/* Key Expressions Card */
.expressions-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 28px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
}

.expressions-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.expr-item {
  background: rgba(0, 0, 0, 0.15);
  border-radius: var(--radius-sm);
  padding: 16px;
  border-left: 4px solid var(--primary-color);
}

.light-theme .expr-item {
  background: rgba(255, 255, 255, 0.6);
}

.expr-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent-light);
  margin-bottom: 6px;
}

.expr-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.result-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 16px;
}

/* ==========================================
   9. History Screen Elements
   ========================================== */
.history-card {
  composes: glass;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 28px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-main);
  backdrop-filter: blur(14px) saturate(180%);
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.history-table-container {
  overflow-x: auto;
  position: relative;
  min-height: 200px;
}

.history-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.history-table th, .history-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-color);
}

.history-table th {
  font-size: 0.85rem;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 600;
  letter-spacing: 0.5px;
}

.history-table td {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.history-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

.light-theme .history-table tbody tr:hover {
  background: rgba(0, 0, 0, 0.01);
}

.history-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 0;
  text-align: center;
  color: var(--text-secondary);
  gap: 12px;
}

.empty-icon {
  font-size: 2.5rem;
}

/* ==========================================
   10. Modals & Overlays
   ========================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeIn var(--transition-fast) forwards;
}

.modal-card {
  width: 100%;
  max-width: 520px;
  background: var(--bg-sub);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  animation: modalScaleUp var(--transition-normal) forwards;
  overflow: hidden;
}

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

@keyframes modalScaleUp {
  from {
    opacity: 0;
    transform: scale(0.95) translateY(10px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
}

.close-btn {
  font-size: 1.8rem;
  color: var(--text-muted);
  line-height: 1;
  transition: color var(--transition-fast);
}

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

.modal-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  background: rgba(0, 0, 0, 0.1);
  display: flex;
  justify-content: flex-end;
}

/* Form Styling */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-help {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.form-group input[type="text"],
.form-group input[type="password"],
.form-group select {
  width: 100%;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  color: var(--text-primary);
  outline: none;
  transition: all var(--transition-fast);
}

.form-group input:focus, .form-group select:focus {
  border-color: var(--primary-color);
  background: rgba(0, 0, 0, 0.3);
}

.input-with-toggle {
  position: relative;
  display: flex;
  align-items: center;
}

.input-with-toggle input {
  padding-right: 44px !important;
}

.input-with-toggle .btn-icon {
  position: absolute;
  right: 6px;
  border: none;
  background: transparent;
}

/* Settings Theme selection */
.theme-options {
  display: flex;
  gap: 8px;
}

.btn-theme-option {
  flex: 1;
  padding: 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: rgba(0, 0, 0, 0.1);
  text-align: center;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.btn-theme-option:hover {
  background: rgba(255,255,255,0.02);
}

.btn-theme-option.active {
  border-color: var(--primary-color);
  background: rgba(var(--primary-color-rgb), 0.1);
  color: var(--text-primary);
  font-weight: 600;
}

/* ==========================================
   11. Loading Overlay & Spinner
   ========================================== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(8, 10, 15, 0.85);
  backdrop-filter: blur(10px);
  z-index: 2000;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeIn var(--transition-fast) forwards;
}

.loader-content {
  text-align: center;
  max-width: 420px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255,255,255,0.05);
  border-top-color: var(--primary-color);
  border-radius: var(--radius-circle);
  animation: spin 1s linear infinite;
  box-shadow: 0 0 15px rgba(var(--primary-color-rgb), 0.2);
}

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

.loader-content h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
}

.loader-content p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ==========================================
   12. Toast Notification Banner
   ========================================== */
.toast-container {
  position: fixed;
  top: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 3000;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  min-width: 250px;
  max-width: 350px;
  background: var(--bg-sub);
  border: 1px solid var(--border-color);
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  box-shadow: 0 10px 30px rgba(0,0,0,0.25);
  display: flex;
  align-items: center;
  gap: 12px;
  animation: toastSlideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  font-size: 0.9rem;
  font-weight: 500;
}

@keyframes toastSlideIn {
  from {
    opacity: 0;
    transform: translateX(30px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateX(0) scale(1);
  }
}

.toast.success {
  border-left: 4px solid var(--color-success);
}

.toast.error {
  border-left: 4px solid var(--color-danger);
}

.toast.warning {
  border-left: 4px solid var(--color-warning);
}

/* ==========================================
   13. Responsive Adjustments
   ========================================== */
@media (max-width: 768px) {
  .app-header {
    height: 70px;
    margin-bottom: 16px;
  }
  
  .header-logo {
    font-size: 1.4rem;
  }
  
  .nav-btn {
    padding: 6px 10px;
    font-size: 0.85rem;
  }
  
  .nav-btn svg {
    width: 16px;
    height: 16px;
  }
  
  .dashboard-hero h1 {
    font-size: 1.9rem;
  }
  
  .difficulty-card, .presets-grid, .custom-card, .practice-header, .dialogue-container, .practice-footer, .result-card, .expressions-card, .history-card {
    padding: 16px;
  }
  
  .presets-grid {
    grid-template-columns: 1fr;
  }
  
  .preset-card {
    height: 180px;
  }
  
  .bubble-box {
    padding: 12px 14px;
  }
  
  .speech-text {
    font-size: 0.95rem;
  }
  
  .blank-input {
    font-size: 0.95rem;
    min-width: 60px;
  }
  
  .action-buttons-group {
    flex-direction: column-reverse;
    gap: 8px;
  }
  
  .action-buttons-group button {
    width: 100%;
  }
  
  .history-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
  
  .history-header button {
    width: 100%;
  }
}