How to position a text inside a rotated div box

Question

Like this

Should be centered too.

.diamond {
    display: block;
    height: 30px;
    width: 30px;
    background-color: white;
    border: 2px solid #dcdcdc;
    transform: rotate(45deg);}

Answer 1

Rotate the content back the other way.

* {
  margin: 0;
  padding: 0;
}
.diamond {
  display: block;
  height: 30px;
  width: 30px;
  background-color: white;
  border: 2px solid #dcdcdc;
  transform: rotate(45deg);
  text-align: center;
  line-height: 30px;
  margin: 25px;
}
.diamond p {
  transform: rotate(-45deg);
}

<div class="diamond">
  <p>Hi</p>
</div>