为什么我给立方体设置backface-visibility: hidden;但是背面还是能够看见?

<!DOCTYPE html>
<html lang="en">

<head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>Document</title>
      <style>
            body{
                  perspective: 700px;
            }
            .BOX{
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  margin: 50px auto;
                  position: relative;
                  transition: 3s;
                  transform-style: preserve-3d;
                  transform-origin: center center -75px;
            }
            
           
            
            .box1 {
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  margin: auto;
                  position: absolute;
            }
            .box1 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
                  grid-area: 2/2/3/3;
                  align-self: center;
                  justify-self: center;
            }
            .box2{
                  position: absolute;
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  transform-origin:left;
                  transform: rotateY(90deg);

            }
            .box2 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
            }
            .box2 div:nth-child(1){
                  grid-area: 1/1/2/2;
                  align-self: center;
                  justify-self: center;
            }
            .box2 div:nth-child(2){
                  grid-area: 3/3/4/4;
                  align-self: center;
                  justify-self: center;
            }
            .box3{
                  position: absolute;
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  transform-origin: right;
                  transform: rotateY(-90deg);
            }
            .box3 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
            }
            .box3  div:nth-child(1){
                  grid-area: 1/1/2/2;
                  align-self: center;
                  justify-self: center;
            }
            .box3 div:nth-child(2){
                  grid-area: 3/3/4/4;
                  align-self: center;
                  justify-self: center;
            }
            .box3 div:nth-child(3){
                  grid-area: 2/2/3/3;
                  align-self: center;
                  justify-self: center;
            }
            .box4{
                  position: absolute;
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  place-items: center center;
                  grid-template-areas: 
                  "a1 a2 a3"
                  "a4 a5 a6"
                  "a7 a8 a9";
                  transform-origin: bottom;
                  transform: rotateX(90deg);
            }
            .box4 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
            }
            .box4 div:nth-child(2){
                  grid-area: a3;
            }
            .box4 div:nth-child(3){
                  grid-area: a7;
            }
            .box4 div:nth-child(4){
                  grid-area: a9;
            }
            .box5{
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  place-items: center center;
                  grid-template-areas: 
                  "a1 a2 a3"
                  "a4 a5 a6"
                  "a7 a8 a9";
                  position: absolute;
                  transform-origin: top;
                  transform: rotateX(-90deg);
            }
            .box5 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
            }
            .box5 div:nth-child(2){
                  grid-area: a3;
            }
            .box5 div:nth-child(3){
                  grid-area: a7;
            }
            .box5 div:nth-child(4){
                  grid-area: a9;
            }
            .box5 div:nth-child(5){
                  grid-area: a5;
            }
            .box6{
                  position: absolute;
                  width: 150px;
                  height: 150px;
                  border: 1px solid black;
                  display: grid;
                  grid-template-columns: repeat(3, 1fr);
                  grid-template-rows: repeat(3,1fr);
                  border-radius: 5px;
                  place-items: center center;
                  grid-template-areas: 
                  "a1 a2 a3"
                  "a4 a5 a6"
                  "a7 a8 a9";
                  transform: translateZ(-150px) rotateY(180deg);
            }
            .box6 div{
                  width: 70%;
                  height: 70%;
                  background: black;
                  border-radius: 50%;
            }
            .box6 div:nth-child(2){
                  grid-area: a4;
            }
            .box6 div:nth-child(3){
                  grid-area: a7;
            }
            .box6 div:nth-child(4){
                  grid-area: a3;
            }
            .box6 div:nth-child(5){
                  grid-area: a6;
            }
            .box6 div:nth-child(6){
                  grid-area: a9;
            }
            .box1.box2.box3.box4.box5.box6{
                  backface-visibility: hidden;
            }
            .BOX:hover {
                  transform: rotateY(360deg);
            }
      </style>
</head>

<body>
      <div class="BOX">
            <div class="box1">
                  <div></div>
            </div>
            <div class="box2">
                  <div></div>
                  <div></div>
            </div>
            <div class="box3">
                  <div></div>
                  <div></div>
                  <div></div>
            </div>
            <div class="box4">
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
            </div>
            <div class="box5">
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
            </div>
            <div class="box6">
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
                  <div></div>
            </div>
      </div>
</body>

</html>

我把box6翻转了180度,并且给box1~6均设置了背面隐藏,为什么不起作用?背面都能看得到?

.box1,.box2,.box3,.box4,.box5,.box6 各个标签之间要用逗号隔开

1.

 [class^='box']{

     backface-visibility: hidden;

 }//以box开头的所有class类

2.我发现box的位置不是很对,我用translate和rotate;如(transform: translateZ(-150px) rotateY(180deg);)

3.#BOX中border要删掉,要不然在6朝向自己的时候可以看到#BOX框