.ztzl {
  display: flex;
  flex-wrap: wrap;
}
.ztzl_box{
    background: url(../images/zwzx/box_bg.png) no-repeat top center;
    min-height: 520px;
margin-bottom:50px;
    padding-top: 20px;
}
.ztzl a {
  width: 23.5%;
  margin-top: 20px;
  margin-right: 20px;
}

.ztzl a:nth-child(4n) {
  margin-right: 0px;
}

.ztzl a img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

@media (max-width: 1280px) {
  .ztzl a {
    width: 31%;
    margin-right: 20px;
  }
  .ztzl a:nth-child(4n) {
    margin-right: 20px;
  }
  .ztzl a:nth-child(3n) {
    margin-right: 0px;
  }
}

@media (max-width: 992px) {
  .ztzl a {
    width: 48%;
    margin-right: 0;
  }
  .ztzl a:nth-child(4n) {
    margin-right: 0px;
  }

  .ztzl {
    justify-content: space-between;
  }
}

@media (max-width: 480px) {
  .ztzl a {
    width: 100%;
  }
}