A Pen by Anonasaurus Rex.

index.html

<div id="parent">
  <div id="child">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris convallis, diam eget mattis mollis, arcu ante pharetra lorem, non rutrum eros sem eget elit
  </div>
</div>

style.css

#parent {
  border: 1px solid black;
  
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 10px;
  right: 10px;
}
#child {
  width: 300px;
  height: 120px;
  border: 1px solid red;
  padding: 10px;
  
  /* Center the box horizontaly and verticaly */
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  
  /* Center the text verticaly in the box */
  display: flex;
  flex-direction: column;
  justify-content: center;
}

ymFiu.markdown

ymFiu

A Pen by Secret Sam on CodePen.

License.