When an element such as a link has an outline defined in CSS (for example as a :focus state) and that element has also been resized through bolding or increasing the font size the outline seems to clip based on the original font size. If you zoom the browser 2-3 times it triggers some kind of repaint and the outline appears.
The only way I have managed to get an outline to render properly in Safari is to add `overflow: auto` to the element which seems to force the outline to render correctly.
Simplified test case here:
Some layout/paint invalidation bug?