padding: 20px 0;
        }
        
        .nav-tabs .nav-link {
            color: var(--dark-color);
        }
        
        .nav-tabs .nav-link.active {
            color: var(--primary-color);
            font-weight: bold;
        }
        
        #calculator-section {
            background-color: white;
            border-radius: 10px;
            padding: 20px;
            margin-top: 20px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }
        
        .calculation-item {
   