Box-sizing

HTML

<div> Content-box </div>
<div> Border-box </div>

CSS

div {
    width: 150px;
    height: 50px;
    background: red;
    padding: 5px 10px;
    border: 5px solid;
    text-align: center;
    margin-bottom: 1px;
    opacity:0.1;
}
div+div {                   /* http://jsfiddle.net/crazyrohila/FDeVh/ for selector example */
    box-sizing: border-box;
}

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Box-sizing

HTML

CSS

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Join the 4+ million users, and keep the JSFiddle dream alive.

Ad-free

Use pre-released features

Fiddle collections

Private collections and fiddles

Console