html,
body,
header,
nav,
footer,
div,
p,
ul,
ol,
li,
a,
span,
em,
i,
strong,
h1,
h2,
h3,
h4,
h5,
h6,
input {
  margin: 0;
  padding: 0;
}
html {
  font-family: "微软雅黑";
  font-size: 16px;
}
li {
  list-style-type: none;
}
a {
  text-decoration: none;
}
img {
  border-width: 0;
}
.fl {
  float: left;
}
.fr {
  float: right;
}
.clear {
  clear: both;
}
.au{
  margin-left: auto;
  margin-right: auto;
}