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

:root {
  --navy: #0d0d1a;
  --navy-light: #1a1a2e;
  --purple: #4a0080;
  --purple-light: #6b21a8;
  --coral: #ff6b6b;
  --teal: #00d9ff;
  --yellow: #ffd93d;
  --green: #00ff88;
  --white: #ffffff;
  --gray: #888888;
  --bg-primary: var(--navy);
  --bg-secondary: var(--navy-light);
  --text-primary: var(--white);
  --text-secondary: var(--gray);
}

body {
  font-family: 'Space Grotesk', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background 0.3s ease;
}

.app.dark {
  --bg-primary: #0d0d1a;
  --bg-secondary: #1a1a2e;
  --text-primary: #ffffff;
  --text-secondary: #888888;
}

.app.light {
  --bg-primary: #f0f4f8;
  --bg-secondary: #ffffff;
  --text-primary: #1a1a2e;
  --text-secondary: #666666;
}

.app.show-grid {
  background-image: 
    radial-gradient(circle, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 20px 20px;
}

.app.light.show-grid {
  background-image: 
    radial-gradient(circle, rgba(0,0,0,0.08) 1px, transparent 1px);
  background-size: 20px 20px;
}

/* Header */
.header {
  background: linear-gradient(135deg, var(--navy-light) 0%, var(--purple) 100%);
  padding: 1.5rem 2rem;
  text-align: center;
  border-bottom: 2px solid rgba(255,255,255,0.1);
}

.title {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(90deg, var(--teal), var(--yellow), var(--coral));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
  letter-spacing: -1px;
}

.tagline {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
}

/* Navigation Tabs */
.tabs {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem;
  background: var(--bg-secondary);
  flex-wrap: wrap;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.tab {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.25rem;
  border: 2px solid transparent;
  border-radius: 50px;
  background: rgba(255,255,255,0.05);
  color: var(--text-secondary);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
}

.tab:hover {
  background: rgba(255,255,255,0.1);
  color: var(--text-primary);
}

.tab.active {
  background: linear-gradient(135deg, var(--purple) 0%, var(--purple-light) 100%);
  border-color: var(--teal);
  color: var(--white);
  box-shadow: 0 4px 20px rgba(0, 217, 255, 0.3);
}

.tab-icon {
  font-size: 1.2rem;
}

.tab-name {
  display: none;
}

@media (min-width: 640px) {
  .tab-name {
    display: inline;
  }
}

/* Main Content */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 1rem;
  gap: 1rem;
}

@media (min-width: 1024px) {
  .main {
    flex-direction: row;
    padding: 2rem;
    gap: 2rem;
  }
}

/* Visualization Area */
.visualization {
  flex: 1;
  min-height: 400px;
  background: var(--bg-secondary);
  border-radius: 16px;
  border: 1px solid rgba(255,255,255,0.1);
  overflow: hidden;
  position: relative;
}

.proof-container {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.proof-canvas {
  flex: 1;
  width: 100%;
  min-height: 300px;
}

.proof-canvas.interactive {
  cursor: grab;
}

.proof-canvas.interactive:active {
  cursor: grabbing;
}

.proof-controls {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem;
  background: rgba(0,0,0,0.3);
  flex-wrap: wrap;
}

.control-btn {
  padding: 0.5rem 1rem;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 8px;
  background: rgba(255,255,255,0.05);
  color: var(--text-primary);
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.control-btn:hover {
  background: rgba(255,255,255,0.15);
  border-color: var(--teal);
}

.control-btn.active {
  background: var(--purple);
  border-color: var(--teal);
}

.control-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.proof-description {
  padding: 0.75rem 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
  background: rgba(0,0,0,0.2);
}

.proof-math {
  padding: 1rem;
  background: rgba(0,0,0,0.2);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
}

.proof-math code {
  color: var(--teal);
}

.gallery-controls {
  justify-content: center;
}

.gallery-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 0.5rem;
  background: rgba(0,0,0,0.2);
}

.nav-btn {
  width: 40px;
  height: 40px;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
  color: var(--text-primary);
  font-size: 1.2rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.nav-btn:hover {
  background: var(--purple);
  border-color: var(--teal);
}

.proof-counter {
  font-family: 'JetBrains Mono', monospace;
  color: var(--text-secondary);
}

/* Sidebar */
.sidebar {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 1024px) {
  .sidebar {
    width: 320px;
  }
}

/* Calculations Panel */
.calculations-panel {
  background: var(--bg-secondary);
  border-radius: 12px;
  padding: 1.25rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.calc-row {
  display: flex;
  justify-content: space-between;
  padding: 0.3rem 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.95rem;
}

.calc-label {
  color: var(--text-secondary);
}

.calc-value {
  font-weight: 600;
}

.calc-value.red { color: var(--coral); }
.calc-value.cyan { color: var(--teal); }
.calc-value.yellow { color: var(--yellow); }

.calc-divider {
  height: 1px;
  background: rgba(255,255,255,0.1);
  margin: 0.75rem 0;
}

.calc-equation {
  margin-top: 1rem;
  padding: 0.75rem;
  background: rgba(255,255,255,0.05);
  border-radius: 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 1rem;
  text-align: center;
}

.red { color: var(--coral); }
.cyan { color: var(--teal); }
.yellow { color: var(--yellow); }

.checkmark {
  color: var(--green);
  font-weight: bold;
}

/* Controls Panel */
.controls-panel {
  background: var(--bg-secondary);
  border-radius: 12px;
  padding: 1.25rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.controls-panel h3 {
  font-size: 1rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.slider-group {
  margin-bottom: 1rem;
}

.slider-group label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.slider {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(255,255,255,0.1);
  outline: none;
  -webkit-appearance: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--purple);
  border: 2px solid var(--teal);
  cursor: pointer;
  transition: transform 0.2s ease;
}

.slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.slider.red::-webkit-slider-thumb {
  background: var(--coral);
}

.slider.cyan::-webkit-slider-thumb {
  background: var(--teal);
}

.toggle-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin: 1rem 0;
}

.toggle {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.toggle input {
  width: 18px;
  height: 18px;
  accent-color: var(--teal);
  cursor: pointer;
}

.random-btn, .get-it-btn {
  width: 100%;
  padding: 0.75rem;
  margin-top: 0.5rem;
  border: none;
  border-radius: 8px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.random-btn {
  background: rgba(255,255,255,0.1);
  color: var(--text-primary);
  border: 1px solid rgba(255,255,255,0.2);
}

.random-btn:hover {
  background: rgba(255,255,255,0.2);
}

.get-it-btn {
  background: linear-gradient(135deg, var(--green) 0%, var(--teal) 100%);
  color: var(--navy);
}

.get-it-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 255, 136, 0.4);
}

/* Fun Facts Ticker */
.ticker {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: rgba(255, 217, 61, 0.1);
  border-top: 1px solid rgba(255, 217, 61, 0.2);
  font-size: 0.9rem;
}

.ticker-icon {
  font-size: 1.2rem;
  animation: pulse 2s infinite;
}

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

.ticker-text {
  color: var(--yellow);
  font-style: italic;
}

/* Footer */
.footer {
  text-align: center;
  padding: 1rem;
  background: var(--bg-secondary);
  font-size: 0.9rem;
  color: var(--text-secondary);
  border-top: 1px solid rgba(255,255,255,0.1);
}

.footer a {
  color: var(--teal);
  text-decoration: none;
  font-weight: 600;
}

.footer a:hover {
  text-decoration: underline;
}

/* Confetti */
.confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: hidden;
  z-index: 1000;
}

.confetti-particle {
  position: absolute;
  border-radius: 2px;
  animation: confetti-fall linear forwards;
}

@keyframes confetti-fall {
  0% {
    transform: translateY(-10px) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(100vh) rotate(720deg);
    opacity: 0;
  }
}

/* Light mode adjustments */
.app.light .header {
  background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
}

.app.light .title {
  background: linear-gradient(90deg, #6366f1, #8b5cf6, #ec4899);
  -webkit-background-clip: text;
  background-clip: text;
}

.app.light .tagline {
  color: #6b7280;
}

.app.light .tabs {
  background: var(--bg-secondary);
  border-bottom-color: rgba(0,0,0,0.1);
}

.app.light .tab {
  background: rgba(0,0,0,0.05);
}

.app.light .tab:hover {
  background: rgba(0,0,0,0.1);
}

.app.light .visualization,
.app.light .calculations-panel,
.app.light .controls-panel {
  border-color: rgba(0,0,0,0.1);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.app.light .footer {
  border-top-color: rgba(0,0,0,0.1);
}

/* Responsive adjustments */
@media (max-width: 640px) {
  .header {
    padding: 1rem;
  }
  
  .title {
    font-size: 1.75rem;
  }
  
  .tagline {
    font-size: 0.85rem;
  }
  
  .tabs {
    gap: 0.25rem;
    padding: 0.75rem;
  }
  
  .tab {
    padding: 0.5rem 0.75rem;
    font-size: 0.8rem;
  }
  
  .main {
    padding: 0.75rem;
  }
  
  .visualization {
    min-height: 350px;
  }
}