body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            display: flex;
            flex-direction: column;
        }
        header, footer {
            background-color: #004080;
            color: white;
            text-align: center;
            padding: 10px 0;
        }
        .container {
            display: flex;
            justify-content: space-between;
            margin: 20px;
        }
        .main-content {
            flex: 1;
            margin: 0 20px;
            padding: 20px;
            border: 1px solid #ddd;
            border-radius: 8px;
            box-shadow: 2px 2px 5px rgba(0,0,0,0.1);
        }
        .side-article {
            width: 20%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 8px;
            margin: 0 10px;
            box-shadow: 2px 2px 5px rgba(0,0,0,0.1);
        }
        form {
            display: flex;
            flex-direction: column;
            max-width: 400px;
            margin: auto;
        }
        input[type="text"], input[type="number"] {
            margin-bottom: 15px;
            padding: 10px;
            border: 1px solid #ccc;
            border-radius: 4px;
        }
        button {
            background-color: #28a745;
            color: white;
            border: none;
            padding: 10px;
            border-radius: 5px;
            cursor: pointer;
        }
        button:hover {
            background-color: #218838;
        }
        .paypal-button {
            display: block;
            margin: 20px auto;
        }