How to display elements in block

Question

I want the elements below to line up under each other. As you can see in the picture the gray element is not lining up like the others.

Answer 1

If what you would like is to replicate the code, you could do it like this:

#holder {
  width: 300px;
  height: 300px;
  border: 1px solid black;
}

#gray {
  width: 100%;
  height: 33.333%;
  background-color: gray;
}

#red {
  width: 100%;
  height: 33.333%;
  background-color: red;
}

#orange {
  width: 100%;
  height: 33.333%;
  background-color: orange;
}

<div id="holder">
  <div id="red">
  </div>
  <div id="gray">
  </div>
  <div id="orange">
  </div>
</div>

If you have current code though that you would like fixed, please post it here :)