https or sll loosing css and link go to http

[Bill]

Hello,

I am a Get Simple CMS beginner so I hope my question is not too stupid

I wonder how to make Get simple CMS site working on https (ssl certificate)

When i put https instead of http, i am loosing all the css and look of the site, the content is displaying ok.

The site link to the page of the site, go systematically to the http version of the site.

Can anyone help me to explain what should be done to have ccs and link going to https ?

Thanks for your help.