彈框的一種簡單css用法

<div class="coverbox">
  <div class="covercont">
      <div class="covernav">
         <span class='close'><img src="/style/images/close.png" style='width:60%;'></span>
      </div>
      <div class="coverbody">
        <div class="coverinfo">

        </div>
        <div class="coverhiden">

        </div>
      </div>
  </div>



/*彈框*/
.coverbox{
    display: none;
    position: fixed;
    z-index: 10000;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    overflow: hidden;
    background: rgba(0,0,0,.6);
    width: 100%;
    height: 100%;
    margin: 0 auto;
    padding:10% 10%;
}
.covercont{
    position: relative;
    overflow: hidden;
    margin: auto;
    /*width: 100%;*/
    width:700px;
    padding-bottom: 44px;
    background: #fff;
}
.covernav{
    position: absolute;
    left:0;
    top: 0;
    height: 44px;
    overflow: hidden;
    width: 100%;
}
.close{
    display: inline-block;
    width: 44px;
    height: 44px;
    line-height: 44px;
    text-decoration: none;
    font-size: 1.4em;
    text-align: center;
    line-height: 2em;
    cursor:pointer;
}
.coverbody{
    height:100%;
    margin-top: 44px;
    padding:0 3em;
    overflow-x: hidden;
}