.grid{
  position: absolute;
  top: 25%;
  left: 5%;
  right: 5%;
  bottom: 25%;
  display: flex;
  flex-wrap: wrap;
  background-color: rgb(169, 110, 245);
  border-radius: 6px;
}
.box{
	position: relative; /* 设置了动画才有效*/
  width: 33.333%;
  height: 33.333%;
  color: white;
  background-color: rgb(161, 97, 245);
  border-radius: inherit;
  display: flex;
  align-items: center;
  justify-content: center;
}
.box.center{
  z-index: 10;
  background-color: rgb(169, 110, 245);
}
.box.center div{
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50%;
  height: 50%;
  border-radius: 6px;
  border: 1px solid rgb(161, 97, 245);
  cursor: pointer;
}
.box::before,
.box::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: inherit;
}
.box::before {
  border-top: 2px solid rgb(169, 110, 245);
  border-left: 2px solid rgb(169, 110, 245);
}
.box::after {
  border-bottom: 2px solid rgb(169, 110, 245);
  border-right: 2px solid rgb(169, 110, 245);
}