@charset "utf-8";
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html{
    width: 100%;
    height: 100%;
    font-size: 20px;
    -ms-text-size-adjust: 100%;
    -webkit-text-size-adjust: 100%; 
}
body{
    height: 100%;
    font-family: sans-serif;
    background-color: #f2f2f2;
}
@media only screen and (max-width: 320px){
    html{
        font-size: 9px;
    } 
}
@media only screen and (min-width: 320px) and (max-width: 352px){
    html{
        font-size: 10px;
    } 
}
@media only screen and (min-width: 352px) and (max-width: 384px){
    html{
        font-size: 12px;
    } 
}
@media only screen and (min-width: 384px) and (max-width: 416px){
    html{
        font-size: 12px;
    } 
}
@media only screen and (min-width: 416px) and (max-width: 448px){
    html{
        font-size: 13px;
    } 
}
@media only screen and (min-width: 448px) and (max-width: 480px){
    html{
        font-size: 14px;
    } 
}
@media only screen and (min-width: 480px) and (max-width: 512px){
    html{
        font-size: 15px;
    } 
}
@media only screen and (min-width: 512px) and (max-width: 544px){
    html{
        font-size: 16px;
    } 
}
@media only screen and (min-width: 544px) and (max-width: 576px){
    html{
        font-size: 17px;
    } 
}
@media only screen and (min-width: 576px) and (max-width: 608px){
    html{
        font-size: 18px;
    } 
}
@media only screen and (min-width: 608px) and (max-width: 640px){
    html{
        font-size: 19px;
    } 
}
@media only screen and (min-width: 640px){
    html{
        font-size: 20px;
    } 
}
ul li ,li {
    list-style-type: none;
}
img{
    width: 100%;
    outline: none;
    vertical-align: middle;
}
input , a {
    outline: none;
    -webkit-appearance: none;
}
a{
    text-decoration: none;
}
i,em{
    font-style: normal;
}
.fl{
    float: left;
}
.fr{
    float: right;
}
.w640{
    min-width: 320px;
    max-width: 640px;
    margin: 0 auto;
}
.shadow {
    box-shadow: 0 0 0 #fff, /*左边阴影*/
                0 0 0 #fff, /*顶部阴影*/
                0 2px 2px #eee, /*底部阴影*/
                0 0 0 #fff;
}