/* 重置样式 */
* {
  padding: 0;
  margin: 0;
  font-size: 14px;
}
ul li {
  list-style: none;
}
a,
a:active,
a:hover,
a:focus {
  text-decoration: none;
  outline: none;
}
input {
  border: none;
  outline: none;
}
button {
  outline: none;
  border: none;
}
h2 {
  text-align: center;
}