Middle of the screen

by vanowm

HTML

<div>
  some text in the background
</div>
<div class="boxH">
  <div class="boxV">
    <div class="boxM">
      this div is in the middle
    </div>
  </div>
</div>

CSS

/* content of this box will be centered horizontally */
.boxH
{
  background-color: rgba(0, 127, 255, 0.2);
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* content of this box will be centered vertically */
.boxV
{
  background-color: rgba(255, 0, 0, 0.2);
  height: 100%;
  display: flex;
  flex-direction: row;
  align-items: center;
}

/* content of this box will be centered horizontally and vertically */
 .boxM
{
  background-color: lightblue;
  padding: 3em;
}