*{
 margin: 0;
 padding: 0;
}
a{
 list-style: none;
}
li{
 list-style: none;
}
.lunbo{
 width: 100%;
}
.lunbo img {
    width: 100%;
}
.content{
 
 height: 500px;
 margin-top: 50px;
 position: relative;
 
 overflow: hidden;
}

}
#item{
 width: 100%;
 height: 100%;
  
}
.item{
 position: absolute;
 opacity: 0;
 transition: all 1s;
 width: 100%;
  
}
.item.active{
 opacity:1;width: 100%;

}
/*img{
 width: 100%;
}*/
#btn-left{
 width: 30px;
 height: 69px;
 font-size: 30px;
 color: white;
 background-color:rgba(0,0,0,0.4);
 line-height: 69px;
 padding-left:5px;
 z-index: 10;/*始终显示在图片的上层*/
 position: absolute;
 left: 0;
 top: 50%;
 transform: translateY(-60%);/*使按钮向上偏移居中对齐*/
 cursor: pointer;
 opacity: 0;/*平时隐藏*/
}
.lunbo:hover #btn-left{
 /*鼠标滑入，显示图标*/
 opacity: 1;
}
 
#btn-right{
 width: 26px;
 height: 69px;
 font-size: 30px;
 color: white;
 background-color:rgba(0,0,0,0.4);
 line-height: 69px;
 padding-left: 5px;
 z-index: 10;
 position: absolute;
 right: 0;
 top: 50%;
 cursor: pointer;
 opacity: 0;
 transform: translateY(-60%);
}
.lunbo:hover #btn-right{
 opacity: 1;
}
#circle{
 height: 20px;
 display: flex;
 position: absolute; 
 right:220px;
 bottom: 0px;
}
.circle{
 width: 30px;
 height: 10px;
 border-radius: 10px;
 border: 2px solid white;
 background: rgba(111,111,111,0.8);
 cursor: pointer;
 margin: 5px;
}
.white{
 background-color: #00b80c;
}