.banner {
  width: 100%;
}

.banner img {
  width: 100%;
  height: auto;
  max-width: 1920px;
  min-width: 1440px;
  margin: 0 auto;
}

.caseCard li {
  width: 365px;
  height: 365px;
  margin-right: 20.5px;
  margin-bottom: 20.5px;
  border-radius: 4px;
  position: relative;
  cursor: pointer;
  float: left;
  overflow: hidden;

}

.caseCard li:nth-child(3n) {
  margin-right: 0;
}

.caseCard li img {
  width: 100%;
  height: 100%;
  border-radius: 4px;

}

.caseCard li .tips {
  border-radius: 4px;

  text-align: center;
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  line-height: 365px;
  color: #fff;
  background: rgba(0, 0, 0, .3);
  font-size: 24px;
  display: none;
}

.caseCard li:hover .tips {
  display: block;
}

.caseCard li:hover img {
  width: 110%;
  max-width: 110%;
  height: 110%;
  margin-top: -5%;
  margin-left: -5%;
}