Resizing background image when viewed in phone

Hi Ron,

We have a site at https://www.sivb.org/meetings/ and they just put in a new header. It’s great on a screen, but when viewed on a phone, the logo part shows fine, but the background image gets taller and looks too big. Is there a css setting that I can use to force the background to resize the height so it isn’t taller than the logo part of the header when viewed on a phone?

Thanks for any insight!

Vicky Rowe