body {
            font-family: Arial, sans-serif;
            background-color: #f4f4f4;
            margin: 0;
            padding: 0;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
        }
        .container {
            background-color: #08a52d;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
            max-width: 400px;
            width: 100%;
            text-align: center;
            position: relative;
        }
        .back-button {
            position: absolute;
            top: 10px;
            left: 10px;
            background: none;
            border: none;
            font-size: 32px; 
            font-weight: bolder;
            color: #fff;
            cursor: pointer;
            padding: 8px;
        }
        .back-button:hover {
            color: #ffa500;
        }
        h1 {
            font-size: 28px;
            color: #ffab10;
            margin-bottom: 15px;
        }
        p {
            font-size: 16px;
            color: #e4e4e4;
            margin-bottom: 20px;
        }
        .momo-info {
            background-color: #f9f9f9;
            padding: 15px;
            border-radius: 5px;
            margin-bottom: 20px;
        }
        .momo-info h2 {
            font-size: 20px;
            color: #444;
            margin-bottom: 10px;
        }
        .momo-number {
            font-size: 24px;
            font-weight: bold;
            color: #08a52d;
            margin: 10px 0;
        }
        .momo-name {
            font-size: 18px;
            color: #444;
            margin: 5px 0;
        }
        .note {
            font-size: 14px;
            color: #888;
        }
        .note1 {
            font-size: 14px;
            color: #555555;
        }
        .future-notice {
            font-size: 14px;
            color: #e4e4e4;
        }
        #payment-api-section {
            display: none;
            margin-top: 20px;
        }