body,div,ul,li,img,h1,h2,h3,h4,h5,h6,span,p{
  margin:0 auto;
  padding: 0;
}
a{
  text-decoration: none;
}
li{
  list-style: none;
}
.clear{
  clear: both;
}
.bg1{
  margin-right: 10px;
  display: inline-block;
  width:20px;
  height: 20px;        
  background: url(../images/tip.png) center top no-repeat;
}
.bg2{
  margin-right: 10px;
  display: inline-block;
  width:20px;
  height: 20px;        
  background: url(../images/tip.png) center center no-repeat;
}
.bg3{
  margin-right: 10px;
  display: inline-block;
  width:20px;
  height: 20px;        
  background: url(../images/tip.png) center bottom no-repeat;
}
/* 顶部 */
@media screen and (min-width:1415px) {
  .header{
      width:1415px;
      margin:10px auto;
      position: relative;
      /*overflow: hidden;*/
      height: 60px; 
      font-size: 1em;
      
  }
  .nav_down{
      display: none;
  }
  .logo{
      float: left;
  }
  .nav{
      margin-top:15px;
      line-height: 60px;
      margin-left:230px; 
      float: left;
  }
  .nav li{
      height:30px;
      line-height: 30px;
      text-align: center;
      width:100px;
      float: left;
      margin:0 25px;
  }


  .nav li:hover a{
      transition: 0.2s;
      color: #fff;
  }
  .nav li:hover{
      transition: 0.2s;
      background:#3191CC;
  }
  .nav a{
      font-family: "Microsoft yahei";
      color: #3191CC;
  }
  /* 导航下拉 */
     .nav_down_list{
        height: 0;
        overflow:hidden;
        position: absolute;
        z-index: 999;
    }
    .nav_down_list li{
        background: #3191CC;
        margin:0;
        float: none;
    }
    .nav_down_list a{
        color: #fff;
        width:100px;
        height:30px;
        display:block;
    }
    .nav_down_list li:hover{
        background: #57a8da;
    }
    .nav li:hover .nav_down_list{
        height: 60px;
        transition: 0.5s;
    }

}
/* 1170px-1415px */
/**********************************************************************************************************************/
@media screen and (min-width:1170px) and (max-width:1415px) {
  .header{
      width:1170px;
      margin:10px auto;
      position: relative;
      /*overflow: hidden;*/
      height: 60px; 
      font-size: 1em;
      
  }
  .nav_down{
      display: none;
  }
  .logo{
      float: left;
  }
  .nav{
      margin-top:15px;
      line-height: 60px;
      margin-left:50px; 
      float: left;
  }
  .nav li{
      height:30px;
      line-height: 30px;
      text-align: center;
      width:100px;
      float: left;
      margin:0 25px;
  }


  .nav li:hover a{
      transition: 0.2s;
      color: #fff;
  }
  .nav li:hover{
      transition: 0.2s;
      background:#3191CC;
  }
  .nav a{
      font-family: "Microsoft yahei";
      color: #3191CC;
  }
  /* 导航下拉 */
     .nav_down_list{
        height: 0;
        overflow:hidden;
        position: absolute;
        z-index: 999;
    }
    .nav_down_list li{
        background: #3191CC;
        margin:0;
        float: none;
    }
    .nav_down_list a{
        color: #fff;
        width:100px;
        height:30px;
        display:block;
    }
    .nav_down_list li:hover{
        background: #57a8da;
    }
    .nav li:hover .nav_down_list{
        height: 60px;
        transition: 0.5s;
    }

}


/* 750px-1415px */
/**********************************************************************************************************************/
@media screen and (min-width:750px) and (max-width:1170px) {
  .header{
      width:100%;
      margin:10px auto;
      position: relative;
      height: 60px; 
      font-size: 1em;
      
  }
      .nav{
          position: absolute;
          top:3.75em;
          z-index: 999;
          background: #fff;
          width:100%;
          display:none;
      }
      .nav li{
          padding-left: 1.5em;
          line-height: 1.8em;
          border-bottom:1px solid #ededed; 
      }
      .nav li a{
          font-size: 1em;
          font-family: "Microsoft yahei";
          color: #333;
      }
      .nav li:hover{
          background: #3191CC;
      }
      .nav li:hover a{
          color: #fff;
      }
      .logo{
          float: left;
      }
      .nav_down{
          margin-top:8px;
          float: right;
      }

}
/* max-width:750px */
/**********************************************************************************************************************/
@media screen and (max-width:750px) {
  .header{
      width:100%;
      margin:10px auto;
      position: relative;
      height: 60px; 
      font-size: 1em;
      
  }
      .nav{
          position: absolute;
          top:3.75em;
          z-index: 999;
          background: #fff;
          width:100%;
          display:none;
      }
      .nav li{
          padding-left: 1.5em;
          line-height: 1.8em;
          border-bottom:1px solid #ededed; 
      }
      .nav li a{
          font-size: 1em;
          font-family: "Microsoft yahei";
          color: #333;
      }
      .nav li:hover{
          background: #3191CC;
      }
      .nav li:hover a{
          color: #fff;
      }
      .logo{
          float: left;
      }
      .nav_down{
          margin-top:8px;
          float: right;
      }

}