HELP: Making the browser smaller squashes the drop down menus and makes them difficult to read

Site URL: https://www.telecare.com.au/

Hi - I'm having issues with the drop down menus in the header of this webpage. Whenever someone makes the window for their browser smaller it makes the header become more squashed and results in the drop-down boxes becoming unreadable as they are transparent and the letters clash with the other drop down menus behind them. I hope I explained that okay :).

Also a sub issue - I am also not sure how to edit the drop down menus anyway as whenever I click on the header to edit it, there never seems to be an option for me customize them - It only seems to let me fiddle with the logo and the "button" - apologies if these are rookie questions I'm very new to the website. 

Hi. Can you take a screenshot of problem? We can check easier