Force browser to use new CSS

I don´t know if it is correct usage, but I think you can force a reload of the css file using a query string:

<link href="mystyle.css?SOME_UNIQUE_TEXT" type="text/css" rel="stylesheet" />

I remember I used this method years ago to force a reload of a web-cam image, but time has probably moved on...

Without using js, you can just keep the css filename in a session variable. When a request is made to the Main Page, you simply compose the css link tag with the session variable name.

Being the ccs file name different, you force the broswer to download it without needing to check what was previusly loaded in the browser.