CSS ::before pseudo-element line-height?

My paragraph has a height/line-height of 50px and text-align: center, which centers the text. But p:before is causing it to increase in height/line-height, causing the text to bump down. I want both p and p:before to be vertically centered.

http://jsfiddle.net/MMAUy/

<p>Hover This</p>
p {
  background: red;
  text-align: center;
  height: 50px;
  line-height: 50px;
  font-size: 14px;
}
p:hover:before {
  content: "icon";
  display: inline-block;
  margin-right: 10px;
  font-size: 3em;
}

The text length varies so I don’t think i can just use position: absolute for the icon…


solution

The reason this occurs, is because line-height is being inherited by the :before elements, which is also an inline-block element.

You could solve this by floating the :before content, thus removing it from the flow, rendering it unaffected by the line-height.

jsFiddle here

HTML

<div>
  <p>Hover This</p>
</div>

CSS

div {
  background: red;
  height: 50px;
  line-height: 50px;
  font-size: 14px;
  text-align:center;
}

div:hover p:before {
  content: "icon icon icon icon";
  margin-right: 10px;
  font-size: 42px;
  float:left;
}
p {
  display:inline-block;
  margin:0px;
}