前端样式初始化

html,body,div,p,b,i,span,dl,dd,dt,ul,ol,li,header,footer,aside,nav,section,img,table,tr,td,tbody,tfoot,thead,th,h1,h2,h3,h4,h5,select,input,button{

    margin:0;

    padding:0;

    box-sizing: border-box;

}

ul,ol{list-style: none;}

img{display: block;}

input{display: block;border:none;}