Please meet the :after css attribute
Not a lot of people use :after when styling a webpage with CSS. That’s a shame because it’s really powerful! And the best thing is there is really good support for this (pseudo) selector so you can use it everywhere you want..
I created a JSFiddle example to show you how to use this powerful css feature: http://jsfiddle.net/FwbQF/2/
In the example I’ll show how to make this popover without any images: