problem with header logo & menu after update

Hi,
After the last update of optimizer theme, i have a problem with the Logo & menu Header. In my child theme i have set a different .center width of 90 %. In the original theme it is as follows:
.center {
width: 85%;
margin: 0
auto
}

in my child theme the 85% is changed to 90%, but it doesn’t seem to work anymore and keeps using the 85% of the original theme.

Could you please help me out? My website is: https://www.catstyecam.nl

Thanks in advance,
Corine