解决浏览器样式差异带来的兼容问题

参考自《css实战手册》

/* reset browser styles */
html, body, div, span, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp,small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary,
time, mark, audio, video {
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  vertical-align: baseline;
}
article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section {
  display: block;
}
body {
  line-height: 1.2;
}
ol { 
  padding-left: 1.4em;
  list-style: decimal;
}
ul {
  padding-left: 1.4em;
  list-style: square;
}
table {
  border-collapse: collapse;
  border-spacing: 0;
}
/* end reset browser styles */