/* 清除浮动 */
.clearfix::after {
  content: "";
  display: table;
  clear: both;
}

/* 全局重置边框 */
*,
*::before,
*::after {
  box-sizing: border-box;
  border: none;
}

/* 全局重置 margin 和 padding */
body,
h1,
h2,
h3,
h4,
h5,
h6,
p,
ul,
ol,
li,
dl,
dt,
dd,
table,
tr,
th,
td,
form,
fieldset,
legend,
input,
textarea,
button,
select {
  margin: 0;
  padding: 0;
}