.area-zoom-btn {
  display: block;
  margin: 6px auto;
  text-align: center;
}
.area-zoom-btn .zoom-btn {
  display: inline-block;
}
.area-zoom-btn .zoom-btn i {
  font-size: 0.8rem;
  letter-spacing: -1px;
  vertical-align: middle;
  height: 25px;
  border-top: 1px solid #777777;   
  float: left;
  border-bottom: 1px solid #777777;
  padding: 0 9px;
  line-height: 22px;
}
.area-zoom-btn .zoom-btn .zoom {
  float: left;
  width: 22px;
  height: 25px;
  border: 1px solid #777777;
  text-indent: -9999px;
  background-color: #ffffff;
  background-image: url("https://jinnny.github.io/blog_source/img_comn.png"); 
  background-repeat: no-repeat;
  background-position: 5px 6px;
  margin-right:5px;
}
.area-zoom-btn .zoom-btn .zoom.zoomout {
  background-position: 5px -53px;
}