.tab {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 55px;
  background-color: #fff;
  width: 100%;
  border-top: 1px solid #ddd;
  display: flex;
  flex-wrap: nowrap;
  z-index: 999;
}
.tab > div {
  width: 25%;
  line-height: 20px;
  padding-top: 30px;
  text-align: center;
  color: #a0a0a0;
}
.tab.on {
  color: #ff6f00;
}
.icon_home {
  background: url(../img/index/icon_home_nor@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_home.on {
  background: url(../img/index/icon_home@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_find {
  background: url(../img/index/icon_discover_nor@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_find.on {
  background: url(../img/index/icon_discover@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_res {
  background: url(../img/index/icon_rss_nor@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_res.on {
  background: url(../img/index/icon_rss@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_my {
  background: url(../img/index/icon_my_nor@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}
.icon_my.on {
  background: url(../img/index/icon_my@3x.png) no-repeat center 0px;
  background-size: 30px auto;
}