* {margin: 0;
    padding: 0;}

a {text-decoration: none;
    color: #000;}

li {list-style: none;}

.nav {position: fixed;
      right: 20px;
      top: 30%;
      width: 48px;
      border-radius: 5px;
      overflow: hidden;
      background-color: #fff;}

.nav a li {width: 100%;
    height: 48px;
    margin-top: 10px;}

.li1 {background-image: url(../images/spring.png);
    background-repeat: no-repeat;
    background-position: -7px 6px;
    background-size: 100%;}

.li2 {background-image: url(../images/spring.png);
    background-repeat: no-repeat;
    background-position: -7px -37px;
    background-size: 100%;}

.li3 {background-image: url(../images/spring.png);
    background-repeat: no-repeat;
    background-position: -7px -80px;
    background-size: 100%;}

.li4 {background-image: url(../images/spring.png);
    background-repeat: no-repeat;
    background-position: -7px -130px;
    background-size: 100%;}

.li5 {background-image: url(../images/spring.png);
    background-repeat: no-repeat;
    background-position: -7px -175px;
    background-size: 100%;}

.changtiao {position: fixed;
    height: 290px;
    width: 8px;
    background-color: #fff;
    right: 88px;
    top: 30%;
    border-radius: 4px;}