样式初始化设置(参考)

html,
body,
div,
span,
h1,
h2,
h3,
h4,
h5,
h6,
p,
a,
img,
b,
u,
i,
dl,
dt,
dd,
ol,
ul,
li,
form,
label,
table,
tbody,
tfoot,
thead,
tr,
th,
td,
article,
aside,
footer,
header,
menu,
nav,
section,
audio,
video,
canvas,{
     
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
ol,
ul {
     
  list-style: none;
}
strong {
     
  font-weight: bold;
}
table {
     
  border-collapse: collapse;
  border-spacing: 0;
}
img {
     
  border: 0;
}
/* 清浮动 */
.clearfix::before,
.clearfix::after {
     
  content: "";
  display: table;
}
.clearfix::after {
     
  clear: both;
}
/* IE 6/7 */
.clearfix {
     
  zoom: 1;
}