:root {
            --primary: #4361ee;
            --primary-dark: #3a56d4;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --border-radius: 10px;
            --box-shadow: 0 6px 15px rgba(0,0,0,0.08);
            --transition: all 0.3s ease;
        }
        
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        
        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            line-height: 1.6;
            color: var(--dark);
            background-color: #f5f7ff;
            padding: 2rem;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        
        .calculator {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            padding: 2.5rem;
            width: 100%;
            max-width: 500px;
            transition: var(--transition);
        }
        
        h1 {
            color: var(--primary);
            margin-bottom: 1.75rem;
            font-weight: 700;
            font-size: 1.8rem;
            text-align: center;
        }
        
        .section {
            margin-bottom: 1.75rem;
            background: #f9fafc;
            padding: 1.25rem;
            border-radius: var(--border-radius);
        }
        
        .section-title {
            font-size: 1.1rem;
            color: var(--primary-dark);
            margin-bottom: 1rem;
            font-weight: 600;
            display: flex;
            align-items: center;
        }
        
        .section-title svg {
            margin-right: 8px;
            width: 18px;
            height: 18px;
        }
        
        .input-group {
            display: flex;
            align-items: center;
            margin-bottom: 0.75rem;
        }
        
        label {
            min-width: 90px;
            font-size: 0.95rem;
            color: var(--gray);
        }
        
        input {
            padding: 0.65rem;
            border: 1px solid #e0e3f1;
            border-radius: var(--border-radius);
            width: 80px;
            margin-right: 1rem;
            font-size: 1rem;
            transition: var(--transition);
        }
        
        select {
            padding: 0.65rem;
            border: 1px solid #e0e3f1;
            border-radius: var(--border-radius);
            font-size: 1rem;
            transition: var(--transition);
            margin-right: 1rem;
            background-color: white;
        }
        
        input:focus, select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.15);
        }
        
        .unit {
            color: var(--gray);
            font-size: 0.9rem;
            min-width: 30px;
        }
        
        button {
            background-color: var(--primary);
            color: white;
            border: none;
            padding: 0.9rem;
            border-radius: var(--border-radius);
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            margin-top: 0.5rem;
            width: 100%;
            font-size: 1rem;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        
        button:hover {
            background-color: var(--primary-dark);
            transform: translateY(-2px);
        }
        
        button svg {
            margin-right: 8px;
        }
        
        .results {
            margin-top: 2rem;
            padding: 1.5rem;
            background-color: var(--light);
            border-radius: var(--border-radius);
            border: 1px solid #e0e3f1;
        }
        
        .result-item {
            display: flex;
            justify-content: space-between;
            margin-bottom: 0.75rem;
            padding-bottom: 0.75rem;
            border-bottom: 1px dashed #e0e3f1;
        }
        
        .result-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
            padding-bottom: 0;
        }
        
        .result-value {
            font-weight: 700;
            color: var(--primary);
            font-size: 1.1rem;
        }
        
        /* Responsive adjustments */
        @media (max-width: 480px) {
            body {
                padding: 1rem;
            }
            
            .calculator {
                padding: 1.5rem;
            }
            
            .section {
                padding: 1rem;
            }
            
            .input-group {
                flex-wrap: wrap;
            }
            
            input, select {
                margin-bottom: 0.5rem;
            }
        }