Only one name in title

Hello,
I create my own wp-sites, but I’m an amateur still.

On my site https://www.juveler.nu I have a problem with the title of the pages. I want the mainpage to be called Juveler.nu as a title, but the other pages to have only the page’s own name name. For example https://juveler.nu/charoit/ has the titlename Charoit.Juveler.nu now which is a bit long. What do I edit in order to let the main page be called Juveler.nu and the separate pages have their own names?
I hope you understand what I mean.
Thanks!