common.css

• {
  padding: 0;
  box-sizing: border-box;
  margin: 0;
  list-style: none;
  font-family: Microsoft YaHei;
  font-size: 18px;
  color: #333;
  }

ul {
list-style: none
}

a {
text-decoration: none;
color: #333;
display: block
}

input {
padding: 0;
margin: 0;
border: none;
outline-style: none;
}

.clear {
clear: both
}

.left {
float: left;
}

.right {
float: right;
}

.hidden {
display: none;
}