web自适应手机浏览器的宽度
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=2.0, user-scalable=yes" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=2.0, user-scalable=yes" />
