/*第二种  找到对应标签清除默认样式*/
body,
dl,
dd,
p,
h1,
h2,
h3,
h4,
h5,
h6 {
    margin: 0;
}

ol,
ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

img {
    border: none;
}

a{
    /* 清除下划线 */
    text-decoration: none;
}