Quickstyle 1.2 for Mac can be downloaded from our website for free. Quickstyle for Mac lies within Internet & Network Tools, more precisely Browser extensions.
From the developer:
Quickstyle is a Safari extension to quickly and conveniently restyle any Web page by adding your own CSS rules to it. Quickstyle features a handy "selector helper" that eases the task of finding the right CSS selector for the rule you want to create, and a built-in stylesheet editor so you can create and edit your rules right on the page. It's a lot easier and faster than using Safari's Web Inspector and editing an external User CSS file.
Quickstyle also features shortcut keys to instantly change the font or font size of an element, or to permanently hide it.
Note: Quickstyle is the next generation of my earlier extension, Rightsizer, and will overwrite Rightsizer on installation. All Rightsizer settings are preserved.
You may want to check out more Mac applications, such as Delete Flash Cookies, yahoo mail or RSS Checker, which might be similar to Quickstyle.