每个浏览器都有一套默认样式，所以为了避免出现不同浏览器之间的默认样式问题
，最好是设置一套默认样式，将浏览器的默认样式清除，下面是css代码：

html,
body,
div,
span,
applet,
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%;font: inherit;vertical-align: baseline;
}/* HTML5 display-role reset for older browsers */
article,
aside,
details,
figcaption,
figure,
footer,
header,
hgroup,
menu,
nav,
section {display: block;
}body {line-height: 1;
}ol,
ul {list-style: none;
}blockquote,
q {quotes: none;
}blockquote:before,
blockquote:after,
q:before,
q:after {content: "";content: none;
}table {border-collapse: collapse;border-spacing: 0;
}