:root {
    --primary-color: #2196F3;
    --primary-dark: #1976D2;
    --secondary-color: #757575;
    --background-color: #f8f8f8;
    --panel-background: #ffffff;
    --text-color: #333333;
    --border-radius: 8px;
    --spacing-unit: 16px;
    --shadow: 0 1px 2px rgba(0,0,0,0.1);
  }
  
  body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    min-height: 100vh;
  }
  
  .app-container {
    max-width: 1440px;
    margin: 0 auto;
    padding: var(--spacing-unit);
  }
  
  .container {
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
  }
  
  /* Sidebar Styles */
  .sidebar {
    width: 320px;
    flex-shrink: 0;
  }
  
  .panel {
    background: var(--panel-background);
    border-radius: var(--border-radius);
    padding: var(--spacing-unit);
    margin-bottom: var(--spacing-unit);
    box-shadow: var(--shadow);
  }
  
  .panel h3 {
    font-size: 14px;
    text-transform: uppercase;
    color: var(--secondary-color);
    margin: calc(var(--spacing-unit) * 1.5) 0 var(--spacing-unit) 0;
    letter-spacing: 0.5px;
  }
  
  /* Upload Area Styles */
  .upload-area {
    border: 2px dashed #e0e0e0;
    border-radius: var(--border-radius);
    padding: calc(var(--spacing-unit) * 1.5);
    text-align: center;
    transition: all 0.3s ease;
  }
  
  .upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(33, 150, 243, 0.05);
  }
  
  .upload-label {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    color: var(--secondary-color);
  }
  
  .upload-icon {
    font-size: 24px;
  }
  
  .upload-input {
    display: none;
  }
  
  /* Control Groups */
  .control-group {
    margin-bottom: var(--spacing-unit);
  }
  
  .control-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 14px;
  }
  
  .slider-container {
    display: flex;
    align-items: center;
    gap: 12px;
  }
  
  input[type="range"] {
    flex: 1;
    height: 4px;
    -webkit-appearance: none;
    background: #e0e0e0;
    border-radius: 2px;
    outline: none;
  }
  
  input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
  }
  
  input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
  }
  
  .value-display {
    min-width: 40px;
    text-align: right;
    font-size: 14px;
    color: var(--secondary-color);
  }
  
  /* Select Styles */
  .dither-select {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    background-color: white;
    font-size: 14px;
    color: var(--text-color);
    cursor: pointer;
  }
  
  /* Button Styles */
  .action-panel {
    display: flex;
    gap: var(--spacing-unit);
  }
  
  .btn {
    flex: 1;
    padding: 12px 24px;
    border: none;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
  }
  
  .btn-primary {
    background-color: var(--primary-color);
    color: white;
  }
  
  .btn-primary:hover {
    background-color: var(--primary-dark);
  }
  
  .btn-secondary {
    background-color: #f5f5f5;
    color: var(--secondary-color);
  }
  
  .btn-secondary:hover {
    background-color: #e0e0e0;
  }
  
  /* Main Content Area */
  .main-content {
    flex: 1;
    min-height: 600px;
    background: var(--panel-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
  }
  
  .canvas-container {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #fff;
  }
  
  canvas {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
  }
  
  /* Responsive Design */
  @media (max-width: 1024px) {
    .container {
      flex-direction: column;
    }
    .sidebar {
      width: 100%;
    }
    .main-content {
      min-height: 400px;
    }
  }