coller pro change logo size

Hi using coller pro on https://www.devonshockwave.co.uk (I’m here at wp support because I was unable to submit a ticket at the pro site – wasn’t working)

Our logo looks very small when limited to a height of 125 – please could we change the main site logo dimensions to: height 200px, and width: 272px?

I’ve tried adding some css to our custom style plugin, but it’s not working for me – perhaps I’m using the incorrect css class.Your help would be greatly appreciated!

Nat