Hi Becky,
I will need a bit more information to understand exactly what you want to achieve.
Can you please describe with more details what you mean by resizable logo in the footer widget?
Would you like them to be bigger? Would you like them to have all the same size?
Your code and IDs are working, but what the code above is doing is setting the limit to max 100% and height auto, what is actually the design you want to achieve?
Let us know and we will help you.
Thanks,
Joao