css水平垂直居中

<div id="father">
 <div id="son">
    我是关键节点
  div>
div>
1
2
3
4
5

已知宽高

#father {
  width: 500px;
  height: 300px;
  background-color: aqua;
  position: relative;
}
#son {
  width: 100px;
  height: 100px;
  background-color: aquamarine;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

#father {
  width: 500px;
  height: 300px;
  background-color: aqua;
  position: relative;
}
#son {
  width: 100px;
  height: 100px;
  background-color: aquamarine;
  position: absolute;
  left: 50%;
  top: 50%;
  margin-left: -50px;
  margin-top: -50px;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

未知宽高

#father {
  width: 500px;
  height: 300px;
  background-color: aqua;
  position: relative;
}
#son {
  background-color: aquamarine;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translateX(-50%) translateY(-50%);
}
1
2
3
4
5
6
7
8
9
10
11
12
13

#father {
  width: 500px;
  height: 300px;
  background-color: aqua;
  display: flex;
  justify-content: center;
  align-items: center;
}
#son {
  background-color: aquamarine;
}
1
2
3
4
5
6
7
8
9
10
11

#father {
  width: 500px;
  height: 300px;
  background-color: aqua;
  display: grid;
}
#son {
  background-color: aquamarine;
  /* 水平居中 */
  justify-self: center; 
  /* 垂直居中 */
  align-self: center;
}
1
2
3
4
5
6
7
8
9
10
11
12
13