body {
  min-width: 640px;
  max-width: 1920px;
  background-color: #f4f4f4;
  font-family: Microsoft YaHei;
  font-size: .3125rem;
}

/* 约束屏幕尺寸 */
@media screen and (max-width: 1024px) {
  html {
    font-size: 42px !important;
  }
}

@media screen and (min-width: 1920px) {
  html {
    font-size: 80px !important;
  }
}

/*  初始化 */
* {
  padding: 0;
  margin: 0;
}

ul {
  list-style: none;
}

a {
  text-decoration: none;
  color: #5D5D5D;
}

button {

  border: none;
  outline: none;
}