/* 公司介绍 */
.introduce {
  display: flex;
  padding: 0px 90px;
  justify-content: space-between;
  box-sizing: border-box;
}

.introduce li {
  width: 278px;
  height: 350px;
}

.main .index_little_manor {
  margin-top: 40px;
}

.nav li:nth-child(1):after,
.nav li:nth-child(1):before {
  opacity: 1;
}

.introduce li {
  position: relative;
}
.introduce li a {
  display: block;
}

.introduce a:hover::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  background: rgba(0, 0, 0, 0.2);
}