清除margin,padding

body,
            div,
            dl,
            dt,
            dd,
            ul,
            ol,
            li,
            h1,
            h2,
            h3,
            h4,
            h5,
            h6,
            pre,
            code,
            form,
            fieldset,
            legend,
            input,
            textarea,
            p,
            blockquote,
            th,
            td {
                margin: 0;
                padding: 0
            }

完整YUI的css:

http://yui.yahooapis.com/3.18.1/build/cssreset/cssreset-min.css

<link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/3.18.1/build/cssreset/cssreset-min.css">

/*
YUI 3.18.1 (build f7e7bcb)
Copyright 2014 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/

html {
  color: #000;
  background: #fff;
}
body,
div,
dl,
dt,
dd,
ul,
ol,
li,
h1,
h2,
h3,
h4,
h5,
h6,
pre,
code,
form,
fieldset,
legend,
input,
textarea,
p,
blockquote,
th,
td {
  margin: 0;
  padding: 0;
}
table {
  border-collapse: collapse;
  border-spacing: 0;
}
fieldset,
img {
  border: 0;
}
address,
caption,
cite,
code,
dfn,
em,
strong,
th,
var {
  font-style: normal;
  font-weight: normal;
}
ol,
ul {
  list-style: none;
}
caption,
th {
  text-align: left;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  font-size: 100%;
  font-weight: normal;
}
q:before,
q:after {
  content: "";
}
abbr,
acronym {
  border: 0;
  font-variant: normal;
}
sup {
  vertical-align: text-top;
}
sub {
  vertical-align: text-bottom;
}
input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  font-weight: inherit;
  *font-size: 100%;
}
legend {
  color: #000;
}
#yui3-css-stamp.cssreset {
  display: none;
}