.bg {
  width: 1920px;
  height: 1000px;
  background: url(../image/bg.png) no-repeat;
  background-size: 100% auto;
  position: relative;
}
.bottom-box {
  width: 1920px;
  height: 80px;
  text-align: center;
  position: absolute;
  bottom: 0px;
}
.bottom-box p {
  color: #999999;
  font-size: 14px;
}
.bottom-box a {
  color: #999999;
}
.nav-ul {
  left: 1500px;
  top: 65px;
  font-size: 18px;
  position: absolute;
}
.nav-ul li {
  float: left;
  color: #FFFFFF;
  margin-right: 30px;
}
.nav-ul a {
  color: #FFFFFF;
}
.us {
  position: relative;
  text-align: center;
}
.back {
  height: 46px;
  width: 363px;
  position: absolute;
  top: 379px;
  left: 780px;
}