body {
            font-family: Arial, sans-serif;
            background-color: #f2f2f2;
            margin: 50px;
            text-align: center;
            color: #fff;
            overflow: hidden;
            font-family: sans-serif;
            background-color: #000000; /* Plain black background */
            background-image: url('img/busyTrafficBG.jpg');
            background-position: center;
            background-size: cover;
            background-attachment: fixed;
            font-size: 1em;
        }
        
        h1 {
            color: #ff0;
            font-size: 1.8em;
        }
        .calculator {
            background-color: #600;
            color: #fff;
            padding: 20px;
            border-radius: 15px;
            width: 400px;
            margin: auto;
            font-size: 1.5em;
        }
        .calculator label {
            display: block;
            margin-bottom: 10px;
            font-weight: bold;
            color: #cc0;
        }
        .calculator input[type="number"] {
            width: 100%;
            padding: 8px;
            margin-top: 5px;
            margin-bottom: 20px;
            box-sizing: border-box;
            font-size: 1em;
        }
        .calculator button {
            padding: 10px 20px;
            background-color: #090;
            border: none;
            color: #fff;
            border-radius: 5px;
            cursor: pointer;
            font-size: 1em;
        }
        .calculator button:hover {
            background-color: #0056b3;
        }
        .result {
            margin-top: 20px;
            font-size: 1.2em;
        }