css怎么初始化？

(1)先访问京东 > 找到第一个css，搜索body，将初始样式扣下来

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

em,
i {
    font-style: normal
}

li {
    list-style: none
}

img {
    border: 0;
    vertical-align: middle
}

button {
    cursor: pointer
}

a {
    color: #666;
    text-decoration: none
}

a:hover {
    color: #c81623
}

button,
input {
    font-family: Microsoft YaHei, Heiti SC, tahoma, arial, Hiragino Sans GB, "\5B8B\4F53", sans-serif
}

body {
    -webkit-font-smoothing: antialiased;
    background-color: #fff;
    font: 12px/1.5 Microsoft YaHei, Heiti SC, tahoma, arial, Hiragino Sans GB, "\5B8B\4F53", sans-serif;
    color: #666
}

.hide,
.none {
    display: none
}

.clearfix:after {
    visibility: hidden;
    clear: both;
    display: block;
    content: ".";
    height: 0
}