Mention Compatibility

[james2doyle]

Perhaps I missed it, but there is nothing pointing out the fact that this uses box-sizing, which some browsers don't support.

Maybe there should be a section listing the browser versions supporting this?

CanIUse.com table

[larsbo]

another problem is that

*, *:after, *:before

affect all elements, for example it changed the height of input fields.

you can add

input {
    -webkit-box-sizing: content-box;
    -moz-box-sizing: content-box;
    box-sizing: content-box;
}

to fix this but maybe there is a better solution?