/* UI Styles */
    .toolbox-container { font-family: 'Inter', 'Segoe UI', system-ui, sans-serif; }
    .category-grid { display: grid; grid-template-columns: repeat(1, 1fr); gap: 15px; margin-bottom: 30px; }
    @media(min-width: 768px) { .category-grid { grid-template-columns: repeat(2, 1fr); } }
    @media(min-width: 1024px) { .category-grid { grid-template-columns: repeat(3, 1fr); } }
    .cat-card { display: flex; align-items: center; padding: 15px; background: #fff; border: 1px solid #ddd; border-radius: 8px; cursor: pointer; transition: 0.2s; }
    .cat-card:hover, .cat-card.active { border-color: #0d6efd; background: #f0f7ff; box-shadow: 0 4px 6px rgba(0,0,0,0.05); }
    .cat-card .icon { font-size: 24px; margin-right: 15px; width: 30px; text-align: center; }
    .workspace { background: #f8f9fa; border: 1px solid #dee2e6; border-radius: 8px; padding: 25px; margin-bottom: 30px; }
    .conversion-row { display: flex; gap: 20px; align-items: stretch; flex-wrap: wrap; margin-top: 20px;}
    .input-block { flex: 1; min-width: 250px; }
    .input-block input, .input-block select { width: 100%; padding: 12px; font-size: 16px; border: 1px solid #ccc; border-radius: 4px; margin-bottom: 10px; }
    .swap-btn { background: #e9ecef; border: 1px solid #ccc; border-radius: 50%; width: 50px; height: 50px; font-size: 24px; cursor: pointer; align-self: center; display: flex; align-items: center; justify-content: center; transition: 0.2s;}
    .swap-btn:hover { background: #dde2e6; }
    
    /* Gas Dashboard Styles */
    .gas-dashboard { display: none; background: #eef2f5; padding: 20px; border-radius: 8px; border: 1px solid #cdd4d9; }
    .gas-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 15px; }
    .gas-card { background: #fff; padding: 15px; border-radius: 4px; border: 1px solid #ddd; }
    .gas-row { display: flex; gap: 10px; margin-bottom: 10px; }
    .gas-input { width: 50%; padding: 8px; border: 1px solid #ccc; border-radius: 4px; }
    
    .info-section { background: #fff; border: 1px solid #ddd; padding: 20px; border-radius: 8px; margin-bottom: 20px; }
    .recent-tag { display: inline-block; background: #eef2f5; border: 1px solid #cdd4d9; padding: 4px 10px; border-radius: 12px; font-size: 13px; margin-right: 8px; margin-bottom: 8px; cursor: pointer;}