How to add a parameter to a request via htaccess?

Question

htaccess

How to make it so that when accessing .css, the GET parameter v=0.5 is added.
That is,
mysite/css/main.css
turns into
mysite/css/main.css? v=0.5
p/s: it is desirable that this change be visible in the address bar

Answer 1

More or less like this

RewriteEngine On
RewriteRule ^/css/main\.css$ /css/main.css?v=0.5 [L]

Or so for all css files

RewriteEngine On
RewriteRule ^([a-z0-9]+\.css)$ /css/$1?v=0.5 [L]