.main_content {
  /* background-image: url(../images/background1.png); */
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center center;
  position: relative;
}
.main_content::before {
  content: "";
  display: block;
  opacity: 0.4;
  background-color: #000000;
  position: absolute;
  width: 100%;
  left: 0;
  top: 0;
  bottom: 0;
  right: 0;
  z-index: 1;
}
.row {
  margin: 0;
}
.title {
  font-size: 36px;
  color: #ffffff;
  text-align: center;
}

.lianxi_box {
  position: absolute;
  top: 400px;
  z-index: 99;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lianxi_box_item {
  text-align: center;
}
.lianxi_box_item img {
  margin-bottom: 30px;
}

.lianxi_box_item img.dw {
  width: 30px;
  height: 30px;
}
.lianxi_box_item img.dh {
  width: 30px;
  height: 30px;
}
.lianxi_box_item img.yx {
  width: 30px;
  height: 30px;
}

.lianxi_box_item span {
  font-size: 18px;
  color: #ffffff;
}