.certificate {
  position: relative;
  padding-bottom: 80px;
}
.certificate .big_title{
  padding: 127px 0 57px;
}
.certificate .content {
  font-size: 0;
}
.certificate .content .item{
  width: 23%;
  /*display: inline-block;*/
  float: left;
  margin-right: 2%;
  margin-bottom: 50px;
  text-align: center;
  height: 418px;
}
.certificate .content .pic {
  padding: 10% 10%;
  /*background: url(../img/border.png) no-repeat center;*/
  /*background-size: contain;*/
}
.certificate .content .item:nth-child(4n){
  margin-right:0;
}
.certificate .content .inner {
  /*border: 10px solid #739458;*/
  box-sizing: border-box;
  cursor: pointer;
  /*height: 270px;*/
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  background-image: url(../img/kuang.png);
  background-size: 100% 100%;
  padding: 17px;
}

.certificate .content .item p {
  /*margin-top: 10px;*/
  font-size: 14px;
  color:#353535;
  height: 40px;
}
.mask {
  align-items: center;
}
.preview {
  width: 100%;
  text-align: center;
}
.preview .pic{
  position: relative;
  display: inline-block;
  width: 369px;
}
.close {
  right: -40px;
  border: 2px solid #fff;
  line-height: 28px;
  color: #fff;
}