.nav {
    background-color: #433f3f;
}
.topBanner {
  width: 100%;
  height: 345px;
  background: url("../images/about_bg.png") no-repeat;
  background-position-x: center;
}
.tban_info {
  width: 500px;
  margin:0 auto;
  color: #fff;
  text-align: center;
  overflow: hidden;
}
.tban_info .info_tit{
  width: 100%;
  margin:0 auto;
  font-size: 32px;
  position: relative;
  letter-spacing: 1px;
  margin-top:110px;
  overflow: hidden;
}
.tban_info .info_tit::after{
  content: '';
    display: inline-block;
  position: absolute;
  top: 42px;  
  right: 0px;
    width: 156px;
  margin-left: 16px;
    height: 1px;
    background: #fff;
}
.info_tit big{
    position: relative;
    z-index: 1;
  color: #fff;
    font-size: 52px;
  margin-right: 6px;
    font-weight: bold;
}
.info_tit span {
  margin-right: 46px;
}
.tban_info .info_txt{
  width: 100%;
  margin:0 auto;
  font-size: 32px;
  position: relative;
  letter-spacing: 1px;
  overflow: hidden;
}
.tban_info .info_txt::before{
  content: '';
    display: inline-block;
  position: absolute;
  top: 22px;  
  left: 0;
    width: 156px;
  margin-right: 16px;
    height: 1px;
    background: #fff;
}
.info_txt em{
  font-size: 30px;
  margin-right: 20px;
  margin-left: 80px;
}
.info_txt span{
  font-size: 26px;
}
.comm_part {
  overflow:hidden;
}
.abus_txt {
  font-size: 18px;
  color: #666;
  line-height: 36px;
  margin-top: 50px;
}