.loading {
    position: fixed;
    top: 0;
    z-index: 999;
    height: 100%;
    width: 100%;
   text-align: center;
    background: #ffffff;
    font-size: 18px;
   visibility: hidden;
   opacity: 0;
   -webkit-animation: loading 2s linear; /**此处是3秒消失，可根据自行需要调整时间**/
 }
 .loading img {
   margin-top: 100px;
 }
 @-webkit-keyframes loading {
   0%{opacity: 1;visibility: visible;}
   90%{opacity: 1;}
   100%{opacity: 0;visibility: visible;} 
 }