Frontrow theme, but i want to customize navigation/dropdown for mobile

I've had this website since squarespace 5.0, the template is FrontRow which was discontinued in 2015. I would like to update it some by changing the navigation menu for the mobile version of the website. 

Link:

https://scottsdalecardetailing.com

I've created folders to subcategorize different pages which look and work great on the desktop version. However, if you go to the mobile version and click menu, it pops up a huge window and all of the pages are unnested, creating a very long list. I would love to have the menu pop open, take up only a portion of the screen (right justified ) rather than full screen and have the subcategories collapsible/accordion-style the same as they are on the desktop version. Can anybody help with this? This theme is very limited on customization since I am running on 7.0 and this theme is discontinued, and I am not super code savvy! Thank you so much!

You can consider changing it to 2 columns (we can give code)

or limit height of each dropdown, then make scroll bar appear

Or (this will more complex + require a Business Plan or higer) show dropdown title only + plus/or arrow icon >> when users click on it >> Show more items.

What do you think?

Quote

i like the last option of having an arrow. I believe I do have a business plan which allows CSS  and code injection

On 3/5/2024 at 2:35 AM, tuanphan said:

You can consider changing it to 2 columns (we can give code)

or limit height of each dropdown, then make scroll bar appear

Or (this will more complex + require a Business Plan or higer) show dropdown title only + plus/or arrow icon >> when users click on it >> Show more items.

What do you think?

can you please help me with this?