I've a web app served by Apache, html pages sent to browsers include several CSS files that are hosted at same web app domain.
I've noticed some websites use my css (and images) including in their pages but this increase my (limited) Apache server traffic.
I want to allow css access only for pages hosted at specific domain(s).
How can I configure the web server (Apache) to refuse serving css outside specific domain(s)?
Example (valid access)
myhost.com/index.html contains inclusion for styles/mystyles.css
Example (invalid access)
foreignhost.com/index.html contains inclusion to myhost.com/styles/mystyles.css