根据您的HTML，我得到此JSFiddle .我只是玩了 transform .

According to your HTML, I get this JSFiddle. I just played with transform.

.mainDiv{
  position: relative;
  width: 206px;
  height: 190px;
  margin: 0px auto;
  margin-top:100px;
}
.square{
  width:100px;
  height:100px;
  background:#c52329;
  border:solid 2px #FFF;
  transform: skew(180deg,210deg);
  position: absolute;
  top: 43px;
}
.square2{
  width:100px;
  height:100px;
  background:#c52329;
  border:solid 2px #FFF;
  transform: skew(180deg,150deg);
  position: absolute;
  left:102px;
  top: 43px;
}
.square3{
  width:114px;
  height:100px;
  background:#c52329;
  border:solid 2px #FFF;
 

transform: rotate(150deg) translate(-40px, -16px) skew(30deg, 0deg);
  position: absolute;
  left: 0px;
  top: -32px;
}

<div class="mainDiv">
  <div class="square"></div>
  <div class="square2"></div>
  <div class="square3"></div>
</div>

更新了CSS

.square3{
  width:114px;
  height:100px;
  background:#c52329;
  border:solid 2px #FFF;
  transform: rotate(150deg) translate(-40px, -16px) skew(30deg, 0deg);
  position: absolute;
  left: 0px;
  top: -32px;
}

我用此更改了转换CSS.

I changed transform CSS with this.

其他:大卫·沃尔什(David Walsh)在立方体上有一个很酷的动画版本.除了看起来很酷之外，通过摆弄设置，您可以学到很多东西.

Extra: David Walsh has a cool animated version on an cube. Apart from the fact that it looks kinda cool, by fiddling with the settings you can learn quite a lot about it.