Style.css has no content except comment

I just opened the style.css file for the responsive theme and it contains no styling css. Only a comment header.
It starts:
/*
Theme Name: Responsive
Theme URI: https://cyberchimps.com/responsive-theme/

… and ends
Read More:

– https://codex.www.ads-software.com/Child_Themes
– https://cyberchimps.com/guide/child-theme-example/
– https://cyberchimps.com/guide-tags/child-theme-2/
*/

thats all there is there..Can someone explain how this is working?

thank you.