: #707070;
            }
            #loading {
                position: fixed;
                top: 0;
                left: 0;
                z-index: 10;
                width: 100vw;
                height: 100vh;
                line-height: 100vh;
                background-color: rgba(0, 0, 0, .4);
                color: #fff;
                text-align: center;
                font-size: 16px;
            }
        </style>
    </head>
    <body>
        <header class="navbar navbar-static-top bs-