如上图所示ul未指定样式，浏览器给了他用户代理样式表，想去掉也很简单，只需要在你的css文件中添加如下css样式，把所有常用元素的尺寸全部重新定义一遍即可。
html, body, div, span, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, abbr, address, cite, code, del, dfn, em, img, ins, kbd, q, samp, small, strong, sub, sup, var, b, i, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, figcaption, figure, footer, header, hgroup, menu, nav, section, summary, time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
}www.tstingmi.com 提供内容。
