/* CSS Variables for Modern Colorful Design */
:root {
  /* Modern Color Palette - Light theme */
  --primary-50: #f0f4ff;
  --primary-100: #e0e7ff;
  --primary-200: #c7d2fe;
  --primary-300: #a5b4fc;
  --primary-400: #818cf8;
  --primary-500: #6366f1;
  --primary-600: #4f46e5;
  --primary-700: #4338ca;
  --primary-800: #3730a3;
  --primary-900: #312e81;

  --secondary-50: #fdf4ff;
  --secondary-100: #fae8ff;
  --secondary-200: #f5d0fe;
  --secondary-300: #f0abfc;
  --secondary-400: #e879f9;
  --secondary-500: #d946ef;
  --secondary-600: #c026d3;
  --secondary-700: #a21caf;
  --secondary-800: #86198f;
  --secondary-900: #701a75;

  --accent-50: #ecfdf5;
  --accent-100: #d1fae5;
  --accent-200: #a7f3d0;
  --accent-300: #6ee7b7;
  --accent-400: #34d399;
  --accent-500: #10b981;
  --accent-600: #059669;
  --accent-700: #047857;
  --accent-800: #065f46;
  --accent-900: #064e3b;

  --orange-50: #fff7ed;
  --orange-100: #ffedd5;
  --orange-200: #fed7aa;
  --orange-300: #fdba74;
  --orange-400: #fb923c;
  --orange-500: #f97316;
  --orange-600: #ea580c;
  --orange-700: #c2410c;
  --orange-800: #9a3412;
  --orange-900: #7c2d12;

  --rose-50: #fff1f2;
  --rose-100: #ffe4e6;
  --rose-200: #fecdd3;
  --rose-300: #fda4af;
  --rose-400: #fb7185;
  --rose-500: #f43f5e;
  --rose-600: #e11d48;
  --rose-700: #be123c;
  --rose-800: #9f1239;
  --rose-900: #881337;

  --warning-50: #fffbeb;
  --warning-100: #fef3c7;
  --warning-200: #fde68a;
  --warning-300: #fcd34d;
  --warning-400: #fbbf24;
  --warning-500: #f59e0b;
  --warning-600: #d97706;
  --warning-700: #b45309;
  --warning-800: #92400e;
  --warning-900: #78350f;

  --error-50: #fef2f2;
  --error-100: #fee2e2;
  --error-200: #fecaca;
  --error-300: #fca5a5;
  --error-400: #f87171;
  --error-500: #ef4444;
  --error-600: #dc2626;
  --error-700: #b91c1c;
  --error-800: #991b1b;
  --error-900: #7f1d1d;

  --success-50: #f0fdf4;
  --success-100: #dcfce7;
  --success-200: #bbf7d0;
  --success-300: #86efac;
  --success-400: #4ade80;
  --success-500: #22c55e;
  --success-600: #16a34a;
  --success-700: #15803d;
  --success-800: #166534;
  --success-900: #14532d;

  /* Neutral colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* Tab-specific color themes */
  --home-primary: var(--primary-600);
  --home-light: var(--primary-100);
  --home-gradient: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-700) 100%);

  --perspective-primary: var(--secondary-600);
  --perspective-light: var(--secondary-100);
  --perspective-gradient: linear-gradient(135deg, var(--secondary-500) 0%, var(--secondary-700) 100%);

  --word-fusion-primary: var(--accent-600);
  --word-fusion-light: var(--accent-100);
  --word-fusion-gradient: linear-gradient(135deg, var(--accent-500) 0%, var(--accent-700) 100%);

  --alternative-uses-primary: var(--orange-600);
  --alternative-uses-light: var(--orange-100);
  --alternative-uses-gradient: linear-gradient(135deg, var(--orange-500) 0%, var(--orange-700) 100%);

  --assumption-reversal-primary: var(--rose-600);
  --assumption-reversal-light: var(--rose-100);
  --assumption-reversal-gradient: linear-gradient(135deg, var(--rose-500) 0%, var(--rose-700) 100%);

  /* Semantic colors - Light theme */
  --color-primary: var(--primary-600);
  --color-primary-hover: var(--primary-700);
  --color-primary-light: var(--primary-100);
  --color-primary-dark: var(--primary-800);
  
  --color-secondary: var(--secondary-600);
  --color-secondary-hover: var(--secondary-700);
  --color-secondary-light: var(--secondary-100);
  
  --color-accent: var(--accent-500);
  --color-accent-hover: var(--accent-600);
  --color-accent-light: var(--accent-100);
  
  --color-warning: var(--warning-500);
  --color-error: var(--error-500);
  --color-success: var(--success-500);
  
  --color-surface: #ffffff;
  --color-surface-variant: var(--gray-50);
  --color-surface-hover: var(--gray-100);
  --color-on-surface: var(--gray-900);
  --color-on-surface-variant: var(--gray-600);
  --color-outline: var(--gray-300);
  --color-outline-variant: var(--gray-200);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-700) 100%);
  --gradient-secondary: linear-gradient(135deg, var(--secondary-500) 0%, var(--secondary-700) 100%);
  --gradient-accent: linear-gradient(135deg, var(--accent-400) 0%, var(--accent-600) 100%);
  --gradient-hero: linear-gradient(135deg, var(--primary-500) 0%, var(--secondary-500) 50%, var(--accent-500) 100%);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  
  /* Border radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
}

/* Dark theme */
[data-theme="dark"] {
  --color-primary: var(--primary-400);
  --color-primary-hover: var(--primary-300);
  --color-primary-light: var(--primary-900);
  --color-primary-dark: var(--primary-200);
  
  --color-secondary: var(--secondary-400);
  --color-secondary-hover: var(--secondary-300);
  --color-secondary-light: var(--secondary-900);
  
  --color-accent: var(--accent-400);
  --color-accent-hover: var(--accent-300);
  --color-accent-light: var(--accent-900);
  
  --color-warning: var(--warning-400);
  --color-error: var(--error-400);
  --color-success: var(--success-400);
  
  --color-surface: var(--gray-900);
  --color-surface-variant: var(--gray-800);
  --color-surface-hover: var(--gray-700);
  --color-on-surface: var(--gray-100);
  --color-on-surface-variant: var(--gray-400);
  --color-outline: var(--gray-600);
  --color-outline-variant: var(--gray-700);
  
  --gradient-primary: linear-gradient(135deg, var(--primary-400) 0%, var(--primary-600) 100%);
  --gradient-secondary: linear-gradient(135deg, var(--secondary-400) 0%, var(--secondary-600) 100%);
  --gradient-accent: linear-gradient(135deg, var(--accent-300) 0%, var(--accent-500) 100%);
  --gradient-hero: linear-gradient(135deg, var(--primary-400) 0%, var(--secondary-400) 50%, var(--accent-400) 100%);

  /* Dark theme tab colors */
  --home-primary: var(--primary-400);
  --home-light: var(--primary-900);
  --home-gradient: linear-gradient(135deg, var(--primary-400) 0%, var(--primary-600) 100%);

  --perspective-primary: var(--secondary-400);
  --perspective-light: var(--secondary-900);
  --perspective-gradient: linear-gradient(135deg, var(--secondary-400) 0%, var(--secondary-600) 100%);

  --word-fusion-primary: var(--accent-400);
  --word-fusion-light: var(--accent-900);
  --word-fusion-gradient: linear-gradient(135deg, var(--accent-400) 0%, var(--accent-600) 100%);

  --alternative-uses-primary: var(--orange-400);
  --alternative-uses-light: var(--orange-900);
  --alternative-uses-gradient: linear-gradient(135deg, var(--orange-400) 0%, var(--orange-600) 100%);

  --assumption-reversal-primary: var(--rose-400);
  --assumption-reversal-light: var(--rose-900);
  --assumption-reversal-gradient: linear-gradient(135deg, var(--rose-400) 0%, var(--rose-600) 100%);
}

/* Base styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-on-surface);
  background: var(--color-surface);
  min-height: 100vh;
  transition: all 0.3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Theme toggle */
.theme-toggle {
  position: fixed;
  top: var(--space-4);
  right: var(--space-4);
  z-index: 1000;
  background: var(--gradient-primary);
  color: white;
  border: none;
  border-radius: var(--radius-full);
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  box-shadow: var(--shadow-xl);
  transform: scale(1.05);
}

/* Top Navigation Tabs */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-outline-variant);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
}

.nav-tabs {
  display: flex;
  max-width: 900px;
  margin: 0 auto;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.nav-tabs::-webkit-scrollbar {
  display: none;
}

.nav-tab {
  background: none;
  border: none;
  padding: var(--space-5) var(--space-6);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-on-surface-variant);
  transition: all 0.3s ease;
  position: relative;
  white-space: nowrap;
  min-width: fit-content;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.nav-tab:hover {
  background: var(--color-surface-hover);
  color: var(--color-on-surface);
  transform: translateY(-1px);
}

/* Tab-specific colors */
.nav-tab[data-view="home"].active {
  color: var(--home-primary);
  background: var(--home-light);
}

.nav-tab[data-view="home"].active::after {
  background: var(--home-gradient);
}

.nav-tab[data-view="perspective"].active {
  color: var(--perspective-primary);
  background: var(--perspective-light);
}

.nav-tab[data-view="perspective"].active::after {
  background: var(--perspective-gradient);
}

.nav-tab[data-view="word-fusion"].active {
  color: var(--word-fusion-primary);
  background: var(--word-fusion-light);
}

.nav-tab[data-view="word-fusion"].active::after {
  background: var(--word-fusion-gradient);
}

.nav-tab[data-view="alternative-uses"].active {
  color: var(--alternative-uses-primary);
  background: var(--alternative-uses-light);
}

.nav-tab[data-view="alternative-uses"].active::after {
  background: var(--alternative-uses-gradient);
}

.nav-tab[data-view="assumption-reversal"].active {
  color: var(--assumption-reversal-primary);
  background: var(--assumption-reversal-light);
}

.nav-tab[data-view="assumption-reversal"].active::after {
  background: var(--assumption-reversal-gradient);
}

.nav-tab.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
}

.nav-tab .material-icons {
  font-size: 20px;
}

/* Bottom Navigation for Mobile */
.bottom-nav {
  display: none;
  position: fixed;
  bottom: var(--space-4);
  left: var(--space-4);
  right: var(--space-4);
  z-index: 200;
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-2xl);
  backdrop-filter: blur(20px);
  padding: var(--space-3);
}

.bottom-nav-tabs {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-1);
}

.bottom-nav-tab {
  background: none;
  border: none;
  padding: var(--space-3) var(--space-2);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-family);
  font-size: var(--font-size-xs);
  font-weight: 500;
  color: var(--color-on-surface-variant);
  transition: all 0.3s ease;
  border-radius: var(--radius-lg);
  min-height: 60px;
  justify-content: center;
}

.bottom-nav-tab:hover {
  background: var(--color-surface-hover);
  color: var(--color-on-surface);
}

.bottom-nav-tab .material-icons {
  font-size: 20px;
}

.bottom-nav-tab .tab-label {
  text-align: center;
  line-height: 1.2;
}

/* Bottom nav tab-specific colors */
.bottom-nav-tab[data-view="home"].active {
  color: var(--home-primary);
  background: var(--home-light);
}

.bottom-nav-tab[data-view="perspective"].active {
  color: var(--perspective-primary);
  background: var(--perspective-light);
}

.bottom-nav-tab[data-view="word-fusion"].active {
  color: var(--word-fusion-primary);
  background: var(--word-fusion-light);
}

.bottom-nav-tab[data-view="alternative-uses"].active {
  color: var(--alternative-uses-primary);
  background: var(--alternative-uses-light);
}

.bottom-nav-tab[data-view="assumption-reversal"].active {
  color: var(--assumption-reversal-primary);
  background: var(--assumption-reversal-light);
}

/* Container */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-6);
  min-height: calc(100vh - 73px);
  display: flex;
  flex-direction: column;
}

/* Views */
.view {
  display: none;
}

.view.active {
  display: block;
}

/* Tab-specific theming for views */
#home-view.active {
  --color-primary: var(--home-primary);
  --color-primary-hover: var(--home-primary);
  --color-primary-light: var(--home-light);
  --gradient-primary: var(--home-gradient);
}

#perspective-view.active {
  --color-primary: var(--perspective-primary);
  --color-primary-hover: var(--perspective-primary);
  --color-primary-light: var(--perspective-light);
  --gradient-primary: var(--perspective-gradient);
}

#word-fusion-view.active {
  --color-primary: var(--word-fusion-primary);
  --color-primary-hover: var(--word-fusion-primary);
  --color-primary-light: var(--word-fusion-light);
  --gradient-primary: var(--word-fusion-gradient);
}

#alternative-uses-view.active {
  --color-primary: var(--alternative-uses-primary);
  --color-primary-hover: var(--alternative-uses-primary);
  --color-primary-light: var(--alternative-uses-light);
  --gradient-primary: var(--alternative-uses-gradient);
}

#assumption-reversal-view.active {
  --color-primary: var(--assumption-reversal-primary);
  --color-primary-hover: var(--assumption-reversal-primary);
  --color-primary-light: var(--assumption-reversal-light);
  --gradient-primary: var(--assumption-reversal-gradient);
}

/* Hero Section */
.hero-section {
  text-align: center;
  margin-bottom: var(--space-12);
  padding: var(--space-8) 0;
}

.hero-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--space-6);
  background: var(--gradient-hero);
  border-radius: var(--radius-2xl);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  animation: float 3s ease-in-out infinite;
}

.hero-icon .material-icons {
  font-size: 40px;
  color: white;
}

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

.app-header h1 {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-4);
  line-height: 1.2;
}

.subtitle {
  color: var(--color-on-surface-variant);
  font-size: var(--font-size-lg);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* Exercise Headers */
.exercise-header {
  text-align: center;
  margin-bottom: var(--space-8);
}

.exercise-header.compact {
  margin-bottom: var(--space-6);
}

.exercise-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto var(--space-4);
  background: var(--gradient-primary);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
}

.exercise-icon .material-icons {
  font-size: 28px;
  color: white;
}

.exercise-header h1 {
  font-size: var(--font-size-3xl);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.exercise-description {
  color: var(--color-on-surface-variant);
  font-size: var(--font-size-base);
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto;
}

/* Cards */
.main-card {
  background: var(--color-surface);
  border: 1px solid var(--color-outline-variant);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  margin-bottom: var(--space-8);
  box-shadow: var(--shadow-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.main-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-primary);
}

.card-content h2 {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  color: var(--color-on-surface);
  margin-bottom: var(--space-3);
}

.card-content p {
  color: var(--color-on-surface-variant);
  margin-bottom: var(--space-6);
  font-size: var(--font-size-base);
}

/* Buttons */
.primary-button {
  background: var(--gradient-primary);
  color: white;
  border: none;
  border-radius: var(--radius-full);
  padding: var(--space-4) var(--space-8);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
  min-height: 48px;
}

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

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

.secondary-button {
  background: var(--color-surface-variant);
  color: var(--color-on-surface);
  border: 1px solid var(--color-outline);
  border-radius: var(--radius-full);
  padding: var(--space-4) var(--space-8);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  transition: all 0.3s ease;
  min-height: 48px;
}

.secondary-button:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-1px);
}

/* Timer settings */
.timer-settings {
  background: var(--color-surface-variant);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
  margin-bottom: var(--space-8);
  border: 1px solid var(--color-outline-variant);
}

.settings-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.settings-header .material-icons {
  color: var(--color-primary);
  font-size: 24px;
}

.settings-header h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-on-surface);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.input-group label {
  font-weight: 500;
  color: var(--color-on-surface);
  font-size: var(--font-size-sm);
}

.input-group input {
  background: var(--color-surface);
  border: 2px solid var(--color-outline);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  font-size: var(--font-size-base);
  color: var(--color-on-surface);
  transition: all 0.3s ease;
}

.input-group input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.input-group input.error {
  border-color: var(--color-error);
}

.input-help {
  font-size: var(--font-size-xs);
  color: var(--color-on-surface-variant);
}

.input-error {
  font-size: var(--font-size-xs);
  color: var(--color-error);
  display: none;
}

.input-error.show {
  display: block;
}

/* Timer section */
.timer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: var(--space-8) 0;
  flex: 1;
  justify-content: center;
}

.timer-section.compact {
  margin: var(--space-4) 0;
  flex: none;
}

.timer-container {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}

.timer-display {
  position: relative;
}

.circular-progress {
  position: relative;
}

.progress-ring {
  transform: rotate(-90deg);
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
}

.progress-ring-circle {
  stroke: url(#progressGradient);
  stroke-width: 6;
  fill: transparent;
  stroke-dasharray: 439.82;
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 1s ease;
  stroke-linecap: round;
}

.progress-ring-background {
  stroke: var(--color-outline-variant);
  stroke-width: 3;
  fill: transparent;
}

.timer-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.timer-value {
  font-size: var(--font-size-3xl);
  font-weight: 600;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}

.timer-adjust-btn.side-btn {
  background: var(--color-surface);
  color: var(--color-on-surface);
  border: 2px solid var(--color-outline);
  border-radius: var(--radius-full);
  padding: var(--space-3);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  transition: all 0.3s ease;
  min-width: 60px;
  min-height: 60px;
  box-shadow: var(--shadow-sm);
}

.timer-adjust-btn.side-btn:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.timer-adjust-btn.side-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.timer-adjust-btn .material-icons {
  font-size: 20px;
}

.btn-label {
  font-size: var(--font-size-xs);
  font-weight: 500;
}

.timer-controls {
  display: flex;
  gap: var(--space-4);
}

.control-button {
  background: var(--color-surface-variant);
  color: var(--color-on-surface);
  border: 2px solid var(--color-outline);
  border-radius: var(--radius-full);
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
}

.control-button:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.control-button.playing {
  background: var(--gradient-primary);
  color: white;
  border-color: var(--color-primary);
}

/* Word Fusion Layout */
.word-fusion-layout {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.words-section {
  text-align: center;
}

.words-section.compact {
  margin: 0;
}

.words-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.word-card {
  background: var(--gradient-accent);
  color: white;
  border-radius: var(--radius-xl);
  padding: var(--space-4);
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.word-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}

.word-card:hover::before {
  left: 100%;
}

.word-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.word-card.loading {
  cursor: default;
  background: var(--color-surface-variant);
}

.word-card h3 {
  font-size: var(--font-size-base);
  font-weight: 600;
  text-transform: capitalize;
}

.refresh-words {
  background: var(--color-surface-variant);
  color: var(--color-on-surface);
  border: 1px solid var(--color-outline);
  border-radius: var(--radius-full);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  transition: all 0.3s ease;
  margin-bottom: var(--space-3);
}

.refresh-words:hover {
  background: var(--color-surface-hover);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* API Status Indicators */
.api-status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  justify-content: center;
  font-size: var(--font-size-sm);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-3);
  font-weight: 500;
}

.api-status.success {
  background: var(--success-100);
  color: var(--success-700);
  border: 1px solid var(--success-200);
}

.api-status.fallback {
  background: var(--warning-100);
  color: var(--warning-700);
  border: 1px solid var(--warning-200);
}

.api-status .material-icons {
  font-size: 16px;
}

.api-error {
  background: var(--color-error);
  color: white;
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  justify-content: center;
  font-size: var(--font-size-sm);
}

/* Exercise actions */
.exercise-actions {
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  margin-top: auto;
  padding-top: var(--space-8);
}

/* Loading spinner */
.loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-outline-variant);
  border-top: 3px solid var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
}

.modal.show {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-2xl);
  animation: modalSlideIn 0.3s ease;
  border: 1px solid var(--color-outline-variant);
}

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

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-6) var(--space-6) var(--space-4);
  border-bottom: 1px solid var(--color-outline-variant);
}

.modal-header h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-on-surface);
  text-transform: capitalize;
}

.modal-close {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-on-surface-variant);
  padding: var(--space-2);
  border-radius: var(--radius-full);
  transition: all 0.3s ease;
}

.modal-close:hover {
  background: var(--color-surface-hover);
  color: var(--color-on-surface);
}

.modal-body {
  padding: var(--space-6);
}

.definition-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-8);
}

.definition-content {
  line-height: 1.6;
}

.definition-content h4 {
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  font-size: var(--font-size-base);
  font-weight: 600;
}

.definition-content p {
  margin-bottom: var(--space-4);
}

.definition-content ul {
  margin-left: var(--space-5);
  margin-bottom: var(--space-4);
}

.definition-error {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-error);
  justify-content: center;
  padding: var(--space-8);
}

/* Add gradient definition for progress ring */
body::before {
  content: '';
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

body::after {
  content: '';
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg"><defs><linearGradient id="progressGradient" x1="0%" y1="0%" x2="100%" y2="0%"><stop offset="0%" style="stop-color:%234f46e5;stop-opacity:1" /><stop offset="50%" style="stop-color:%23d946ef;stop-opacity:1" /><stop offset="100%" style="stop-color:%2310b981;stop-opacity:1" /></linearGradient></defs></svg>');
}

/* Responsive design */
@media (max-width: 768px) {
  .container {
    padding: var(--space-4);
    padding-bottom: 100px; /* Space for bottom navigation */
  }
  
  .hero-section {
    padding: var(--space-6) 0;
    margin-bottom: var(--space-8);
  }
  
  .hero-icon {
    width: 60px;
    height: 60px;
  }
  
  .hero-icon .material-icons {
    font-size: 30px;
  }
  
  .app-header h1 {
    font-size: var(--font-size-3xl);
  }
  
  .exercise-header h1 {
    font-size: var(--font-size-2xl);
  }
  
  .main-card {
    padding: var(--space-6);
  }
  
  .exercise-actions {
    display: none; /* Hide desktop navigation on mobile */
  }
  
  .words-container {
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--space-2);
  }
  
  .word-card {
    min-height: 60px;
    padding: var(--space-3);
  }
  
  .word-card h3 {
    font-size: var(--font-size-sm);
  }
  
  .theme-toggle {
    top: var(--space-3);
    right: var(--space-3);
    width: 48px;
    height: 48px;
  }

  /* Hide top navigation on mobile */
  .top-nav {
    display: none;
  }

  /* Show bottom navigation on mobile */
  .bottom-nav {
    display: block;
  }
  
  /* Mobile timer layout - horizontal buttons */
  .timer-container {
    flex-direction: row;
    gap: var(--space-4);
    justify-content: center;
    align-items: center;
  }
  
  .timer-adjust-btn.side-btn {
    min-width: 56px;
    min-height: 56px;
    padding: var(--space-3);
  }
  
  .timer-display {
    transform: scale(0.85);
  }
  
  .word-fusion-layout {
    gap: var(--space-4);
  }
}

@media (max-width: 480px) {
  .container {
    padding: var(--space-3);
    padding-bottom: 100px; /* Space for bottom navigation */
  }
  
  .timer-display {
    transform: scale(0.75);
  }
  
  .modal-content {
    width: 95%;
  }
  
  .primary-button,
  .secondary-button {
    padding: var(--space-3) var(--space-6);
    font-size: var(--font-size-sm);
  }
  
  .timer-container {
    gap: var(--space-3);
  }
  
  .timer-adjust-btn.side-btn {
    min-width: 48px;
    min-height: 48px;
    padding: var(--space-2);
  }
  
  .words-container {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  
  .word-card {
    min-height: 50px;
  }

  .bottom-nav-tab {
    padding: var(--space-2);
    min-height: 56px;
  }

  .bottom-nav-tab .material-icons {
    font-size: 18px;
  }

  .bottom-nav-tab .tab-label {
    font-size: 10px;
  }
}

/* Accessibility improvements */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .hero-icon {
    animation: none;
  }
}

/* Focus styles */
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .main-card,
  .word-card {
    border-width: 2px;
  }
}