You could use something like Stylish. Firefox: https://addons.mozilla.org/en-US/firefox/addon/stylish/ https://addons.mozilla.org/en-US/firefox/addon/stylish/

You could use something like Stylish. Firefox: https://addons.mozilla.org/en-US/firefox/addon/stylish/ https://addons.mozilla.org/en-US/firefox/addon/stylish/ Chrome: https://chrome.google.com/webstore/detail/stylish-custom-themes-for/fjnbnpbmkenffdnngjfgmeleoegfcffe?hl=en https://chrome.google.com/webstore/detail/stylish-custom-the... Collection of custom stylesheets: https://userstyles.org/ https://userstyles.org/ Userscripts are the same concept for JavaScript; see https://greasyfork.org/en https://greasyfork.org/en