When developing and adjusting the CSS, a methodology is using firebug to directly edit the styles and then re-apply the change on the real file with the editor.
In other cases, it’s more practical to change the CSS directly, but reloading the full page is a bit time consuming.
Here is a trick to reload only the CSS. There are browser extensions for it, but at the time of writing, none of existing ones works as expected, at least on chrome.
From your browser toolbar: right click and select the option to add a new URL (“Add Page” on Chrome)
name: “Reload CSS”
url: the following script
Or just drag this into the toolbar Reload CSS