行内元素，编辑器下换行，浏览器下预览会有间隙
<body> <span>1</span> <span>1</span> <span>1</span> <span>1</span> <span>1</span> <span>1</span> <p>同样的行内元素</p> <span>1</span><span>1</span><span>1</span><span>1</span> </body>
解决办法好像和font-size:0有关
