Hello, Marjo!
I’ve visited your web page and do not see the problem you are describing (probably you have shortened the names in the main menu)…
There are several ways to solve that if you will need …
The first is to expand Layout width (Customizing-> Layout-> General)
https://prnt.sc/lqfgy4
The next solution is to set the smaller font size for the screens below the some defined width.
@media only screen and (max-width: 1100px){
#masthead .agama-primary-nav a {
font-size: 14px;}
}
https://prnt.sc/lqfno1
Change the max-width and font-size values per your needs.
Hope that will help you… if not, fill free to contact me again.
Regards