*{ margin: 0px ; padding: 0px }
li{ list-style: none;}
.clear{ clear: both; }
.ban{ margin:auto;
      width: 1903px;
      height: 700px;
      overflow: hidden;
      position: relative; 
       }

/*.tu img{ float: left; }*/
.tu li{ float: left; }

.btn{ width: 48px;
      height: 48px;
      position: absolute;
      border-radius: 50%;
      display: none; 
       }
.leftB{ background: url(zuo.png) -6px -8px no-repeat;
        left: 20px;
        top: 300px;
         }
.rightB{ background: url(you.png) -5px -2px no-repeat;
        right: 20px;
        top: 300px;
        }
.ban:hover .btn{ display: block;  }
.kuai{ width: 490px;height: 215px;
       background:rgba(255,255,255);
       position: absolute; left: 20%;top: 350px;
       opacity:0.8;
       padding: 28px 45px;
       box-sizing: border-box; }
.kuai h3{font-size: 32px;}
.kuai p {
    font-size: 18px;
    margin: 14px 0;
}
.kuai a {
    display: inline-block;
    border: 1px solid #acacac;
    width: 140px;
    height: 36px;
    line-height: 36px;
    text-align: center;
    color: #2c318d;
    transition: all 400ms;
    text-decoration: none;}
.kuai a:hover{background: #2c318d;color: #fff;}
.section2{width: 100%;
       margin: auto;
       background: #d9d9d9;
       height: 540px;}
.santu{ width: 1200px;
        height: 540px;
        margin:auto; }
.santu li{width: 330px;
          height:400px;
          background: #fff;
          float: left;
          margin: 70px 30px;}
.santu li a{    display: block;
    background-color: #fff;
  color: #333;
    cursor: pointer;}
.santu li img{ width: 100%;
               height: 205px; }
.santu p{ padding: 25px;
          box-sizing: border-box;
          width: 100%;
          height: 150px; }