.modal {
            display: none;
            position: fixed;
            z-index: 1000;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0,0,0,0.5);
        }
        .modal-content {
            background-color: #fefefe;
            margin: 5% auto;
            padding: 20px 2px 10px;
            border: 1px solid #888;
            width: 585px;
            text-align: center;
        }
        .modal-content img {
            max-width: 508px;
        }

        #verifyPayBtn:disabled {
            opacity: 0.6;
            cursor: not-allowed;
        }