html{
    height: 100%;
    /* overflow: hidden; */

}
body{
   height: 100%;
}
div.modal-mask{
    width:100%;
    height: 100%;
    background-color: black;
    opacity: 0.5;
    position:absolute;
    top:0;
    left: 0; 
    z-index: 9999;  
}
div.modal-box{
  
    width:300px;
    height: 150px;
    border: 1px solid #9c9c9c;
    border-radius: 10px;
    position: absolute;
    top:calc((100% - 150px) / 2);
    left:calc((100% - 300px) / 2);
    background-color: #e9e9e9;
    box-shadow: 0 0 2px #444;
    z-index: 10000;  
}
div.modal-box .modal-message{
    text-align: center;
    margin-top: 35px;
    font-size: 18px;
    color: #444;
}
div.modal-box .modal-button-box{
    height: 50px;
    position: absolute;
    bottom:0;
    width: 100%;
    border-top: 1px solid silver;
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
}
.modal-button-box div{
    height: 49px;
    width:98%;
    text-align: center;
    line-height: 50px;
    cursor: pointer;
    border-radius: 10px;
}