CSS 垂直居中的几种方式

.parent {
  padding: 20px 0;
}

.child {}

.parent {
  display: flex;
  justify-content: center;
  align-items: center;
}

.child {}

.parent {
  position: relative;
}

.child {
  position: absolute;
  margin: auto;
  width: 300px;
  height: 200px;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.parent {
  position: relative;
}

.child {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
}

.parent {
  display: grid;
}

.child {
  place-self: center;
}