body, html {
            height: 100%;
            margin: 0;
            display: flex;
            flex-direction: column;
        }
        h2 {
                margin-bottom: 20px;
            }
        .container {
            flex: 1;
            max-width: 900px;
            padding-top: 30px;
        }
        .calc-container {
            display: flex;
            flex-wrap: wrap;
        }
        .calc-form {
            flex: 4;
            min-width: 300px;
            padding: 10px;
        }
        .calc-result {
            flex: 1;
            min-width: 300px;
            padding: 20px;
            background-color: #f8f9fa;
            border-radius: 5px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
            text-align: center;
            height:2em;
            min-height: 150px;
            margin-top:10px;
        }
        .form-group {
            margin-bottom: 10px;
            display: flex;
            align-items: center;
        }
        .form-group label {
            flex: 2;
            margin-bottom: 0;
        }
        .form-group select {
            flex: 1;
        }
        .alert {
            display: none;
            margin-top: 10px;
        }
          .footer {
            background-color: #f8f9fa;
            padding: 20px;
            text-align: center;
            border-top: 1px solid #ccc;
            margin-top: 50px;
            width: 100%;
        }
        @media (max-width: 768px) {
            h2 {
                margin-bottom: 10px;
            }
            .container {
             padding-top: 10px;
            }
            .calc-container {
                flex-direction: column;
            }
        }