My secret weapon for squashing tricky layout and UI bugs is Pesticide. https://github.com/mrmrs/pesticide https://github.com/mrmrs/pesticide https://addons.moz

My secret weapon for squashing tricky layout and UI bugs is Pesticide. https://github.com/mrmrs/pesticide https://github.com/mrmrs/pesticide https://addons.mozilla.org/en-US/firefox/addon/pesticide-css-for-firefox/ https://addons.mozilla.org/en-US/firefox/addon/pesticide-css... It's basically the more sophisticated way of putting a border on everything. The hover interactions are great for revealing elements you didn't think you were hovering over.