全部是按照老师所讲的敲得代码，为何打开后浏览器不显示侧栏，谁帮我看一下啊谢谢

.toolbar-layer, .toolbar-item {

  background-image: url(../img/toolbar.png);

  background-repeat: no-repeat;

}

.toolbar {

  position: fixed;

  left: 50%;

  bottom: 5px;

  margin-left: -26px;

}

.toolbar-item {

  position: relative;

  display: block;

  width: 52px;

  height: 52px;

  margin-top: 1px;

  -webkit-transition: background-position 1s;

  -moz-transition: background-position 1s;

  -ms-transition: background-position 1s;

  -o-transition: background-position 1s;

  transition: background-position 1s;

}

.toolbar-item:hover .toolbar-layer {

  opacity: 1;

  filter: alpha(opacity=100);

  -webkit-transform: scale(1);

  -moz-transform: scale(1);

  -ms-transform: scale(1);

  -o-transform: scale(1);

  transform: scale(1);

}

.toolbar-layer {

  position: absolute;

  right: 46px;

  bottom: -10px;

  width: 172px;

  opacity: 0;

  filter: alpha(opacity=0);

  -webkit-transform-origin: 95% 95%;

  -moz-transform-origin: 95% 95%;

  -ms-transform-origin: 95% 95%;

  -o-transform-origin: 95% 95%;

  transform-origin: 95% 95%;

  -webkit-transform: scale(0.01);

  -moz-transform: scale(0.01);

  -ms-transform: scale(0.01);

  -o-transform: scale(0.01);

  transform: scale(0.01);

  -webkit-transition: all 500ms;

  -moz-transition: all 500ms;

  -ms-transition: all 500ms;

  -o-transition: all 500ms;

  transition: all 500ms;

}

.toolbar-item-weixin {

  background-position: 798px;

}

.toolbar-item-weixin:hover {

  background-position: 0 -860px;

}

.toolbar-item-weixin .toolbar-layer {

  height: 212px;

  background-position: 0 0;

}

.toolbar-item-feedback {

  background-position: 426px;

}

.toolbar-item-feedback:hover {

  background-position: 0 -488px;

}

.toolbar-item-app {

  background-position: 550px;

}

.toolbar-item-app:hover {

  background-position: 0 -612px;

}

.toolbar-item-app .toolbar-layer {

  height: 194px;

  background-position: 0 -222px;

}

.toolbar-item-top {

  background-position: 674px;

}

.toolbar-item-top:hover {

  background-position: 0 -736px;

}