html兼容h5端的设置

H5页面窗口自动调整到设备宽度，并禁止用户缩放页面

媒体查询实现

@media screen and (min-width: 320px) {
    html {font-size: 12px;}
}

@media screen and (min-width: 360px) {
    html {font-size: 14px;}
    
}

@media screen and (min-width: 400px) {
    html {font-size: 18px;}
    
}

@media screen and (min-width: 440px) {
    html {font-size: 20px;}
   
}

@media screen and (min-width: 480px) {
    html {font-size: 22px;}
}

@media screen and (min-width: 640px) {
    html {font-size: 26px;}
    
}