html, body {

  width: 100%;

  height: 100%;

  display: flex;

}

​

div {

  width: 0px;

  height: 0px;

  margin: auto;

}

​

.normal {

  border-top: 50px solid yellowgreen;

  border-bottom: 50px solid deeppink;

  border-left: 50px solid bisque;

  border-right: 50px solid chocolate;

}

​

.top {

  border: 50px solid transparent;

  border-bottom: 50px solid deeppink;

}

​

.left {

  border: 50px solid transparent;

  border-right: 50px solid deeppink;

}

​

.bottom {

  border: 50px solid transparent;

  border-top: 50px solid deeppink;

}

​

.right {

  border: 50px solid transparent;

  border-bottom: 50px solid deeppink;