Responsive mobile site – search bar and menu

Hi there,

I have been trying to adapt my Museum theme for mobile and was hoping that I could get my search bar to enlarge itself on mobile as you type to show the word typed or to simply show up larger in the first instance.

I was also hoping to get my mobile menu to collapse so that it shows only the main menu links unless you click on one that has a dropdown submenu, at which point that submenu expands.

Would someone please be able to help me achieve these two features? My site is julialloydgeorge.com

Thanks!