I have a <div>
element and I want to put a border on it. I know I can write style="border: 1px solid black"
, but this adds 2px to either side of the div, which is not what I want.
I would rather have this border be -1px from the edge of the div. The div itself is 100px x 100px, and if I add a border, then I have to do some mathematics to make the border appear.
Is there any way that I can make the border appear, and ensure the box will still be 100px (including the border)?
Set box-sizing
property to border-box
:
div {
box-sizing: border-box;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
width: 100px;
height: 100px;
border: 20px solid #f00;
background: #00f;
margin: 10px;
}
div + div {
border: 10px solid red;
}
<div>Hello!</div>
<div>Hello!</div>
It works on IE8 & above.