Twenty Twelve: Extend Margins Beyond Parent Element

It always seemed to be a simple matter to make a child element wider than the parent element. You just give the child element negative right and left margins and you’re done. So I was totally perplexed when this did not work the first time I created a child theme for Twenty Twelve. I wasted way too much time trying to figure this out and finally found that it was really very simple: Twenty Twelve has a rule that says:

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site. {
overfow: hidden;
}

Changing it to “overflow:visible;” solved the problem.