.pd-t-b.Certificate2  {
  padding-top: 50px;
  padding-bottom: 80px;
}

@media screen and (max-width:1440px) {
  .pd-t-b.Certificate2  {
    padding: 50px 0;
  }
}

@media screen and (max-width:991px) {
  .pd-t-b.Certificate2  {
    padding: 30px 0;
  }
}

.ytht-mb-30 {
  margin-bottom: 30px;
}
.Certificate2 h3 {
  font-size: clamp(24px, 1.9vw, 36px);
  text-align: center;
  margin-bottom: 35px;
}
.cert-list1 {
  text-align: center;
}
@media(min-width: 768px) {
.cert-list1 .col-lg-13 {
  -ms-flex: 0 0 20%;
  -webkit-box-flex: 0;
  flex: 0 0 20%;
  max-width: 20%;
}
}
/*.cert-list1 ul {
  margin: 0 0 0 -2%;
}*/

/* .cert-list1 ul li {
  float: left;
  width: 23%;
  margin: 0 0 20px 2%;
  text-align: center;
} */

.cert-list1 ul li a {
  display: block;
  width: 100%;
  position: relative;
  z-index: 1;
  overflow: visible;
}

/* 四角阴影（你之前要的） */
.cert-list1 ul li a::before {
  content: '';
  position: absolute;
  inset: 2px;
  z-index: -1;
  /* box-shadow: 2px 2px 4px rgba(0,0,0,0.15),
             -2px -2px 4px rgba(0,0,0,0.15),
             2px -2px 4px rgba(0,0,0,0.15),
             -2px 2px 4px rgba(0,0,0,0.15); */
}

/* 图片 + 渐变边框 */
.cert-list1 ul li img {
  width: 100%;
  display: block;
  box-sizing: border-box;
  /* 高级灰色渐变边框 */
  padding: 6px;
  background: linear-gradient(135deg, #bbb7b7, #ededed, #ededed, #bbb7b7);
  border: 3px solid #dfdfdf;;
}

.cert-list1 ul li p {
  font-size: 16px;
  margin: 10px 0 0 0;
  color: #252525;
}

@media screen and (max-width: 768px) {
  .main {
    padding-top: 25px;
    padding-bottom: 30px;
  }

  /* .cert-list1 ul li {
    width: 48%;
    margin: 0 0 15px 2%;
  } */

  .cert-list1 ul {
    padding: 0 15px;
  }

}