body,h1,h2,h3,h4,h5,h6,p,dl,dd,ul,ol,pre,form,input,textarea,th,td,select{margin:0;padding:0;}
em{font-style:normal;}
li{list-style:none;}
a{text-decoration:none;}
img{border:none; vertical-align:top;}
table{border-collapse:collapse;}
textarea{ resize:none;overflow:auto;}
input{outline:none;}
.clear{zoom:1;}
.clear:after{content:"";display:block;clear:both;}
html,body{width:100%;height:100%;overflow: hidden;}
.full_screen{width:100%;height:100%;}
.full_screen img{width:100%;height:100%;
    /*兼容性object-fit写法*/
    /*-moz-object-fit:cover ;*/
    /*-ms-object-fit:cover ;*/
    /*-webkit-object-fit:cover ;*/
    /*object-fit: cover;*/
}