/* Modern CSS Variables */
:root {
  /* Neutral base */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --text-primary: #1a1a1a;
  --text-secondary: #6c757d;
  
  /* Accent */
  --accent: #0066cc;
  --accent-hover: #0052a3;
  
  /* Semantic */
  --success: #28a745;
  --warning: #ffc107;
  --error: #dc3545;
  
  /* Borders */
  --border-color: #dee2e6;
  --border-radius: 8px;
  
  /* Spacing */
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
}

/* Header */
header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Main Layout - CSS Grid */
main {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--spacing-xl);
  margin: var(--spacing-xl) 0;
}

/* Controls Panel */
.controls {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

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

.input-group label {
  font-weight: 600;
  font-size: 0.95rem;
}

.input-group textarea,
.input-group input[type="text"],
.input-group select {
  padding: 0.75rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-family: inherit;
  transition: all 0.2s ease;
}

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

.input-group input[type="range"] {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--border-color);
  outline: none;
  cursor: pointer;
}

.input-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  transition: all 0.2s ease;
}

.input-group input[type="range"]::-webkit-slider-thumb:hover {
  background: var(--accent-hover);
  transform: scale(1.1);
}

.input-group input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.input-group input[type="range"]::-moz-range-thumb:hover {
  background: var(--accent-hover);
  transform: scale(1.1);
}

#density-value {
  font-weight: 600;
  color: var(--accent);
}

.input-group textarea {
  resize: vertical;
  min-height: 80px;
}

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

/* Radio Group */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.radio-group label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius);
  transition: background-color 0.2s ease;
}

.radio-group label:hover {
  background-color: var(--bg-secondary);
}

.radio-group input[type="radio"] {
  cursor: pointer;
}

/* Seed Controls */
.seed-controls {
  display: flex;
  gap: var(--spacing-sm);
}

.seed-controls input {
  flex: 1;
}

/* Buttons */
button {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-primary {
  background-color: var(--accent);
  color: white;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.3);
}

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

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--border-color);
}

.btn-icon {
  padding: 0.5rem 0.75rem;
  background-color: var(--bg-secondary);
  font-size: 1.2rem;
}

.btn-icon:hover {
  background-color: var(--border-color);
}

/* Canvas Container */
.canvas-container {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-secondary);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  min-height: 500px;
}

#plate-canvas {
  max-width: 100%;
  height: auto;
  border-radius: 50%;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.loading {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: rgba(255, 255, 255, 0.95);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.warning {
  position: absolute;
  bottom: var(--spacing-lg);
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--warning);
  color: var(--text-primary);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius);
  font-size: 0.9rem;
  max-width: 90%;
  text-align: center;
}

/* Actions */
.actions {
  display: flex;
  gap: var(--spacing-md);
  grid-column: 1 / -1;
  justify-content: center;
}

/* Footer */
footer {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-lg);
  border-top: 2px solid var(--border-color);
  text-align: center;
}

.disclaimer {
  color: var(--text-secondary);
  font-size: 0.9rem;
  max-width: 800px;
  margin: 0 auto;
}

/* Responsive - Mobile First */
@media (max-width: 768px) {
  main {
    grid-template-columns: 1fr;
  }
  
  .controls {
    order: 2;
  }
  
  .canvas-container {
    order: 1;
  }
  
  .actions {
    order: 3;
    flex-direction: column;
  }
  
  header h1 {
    font-size: 2rem;
  }
  
  .container {
    padding: var(--spacing-md);
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .container {
    padding: var(--spacing-md);
  }
  
  main {
    grid-template-columns: 1fr 1.5fr;
  }
}

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

.canvas-container canvas {
  animation: fadeIn 0.5s ease;
}