Horizontal Sub Menu

This is a bit of a desperate plee for help…as I’ve followed my usual paths of using Google and following tutorials to find the answers to my questions:

I’m currently trying to turn a vertical sub-menu in a WordPress theme to a horizontal sub-menu, but am so far failing.

Please see my test site for how far I’ve got:

https://www.test.thebreaker.co.uk

All I need to know to complete the transformation, is how to get all the sub-menus to start from the same place – the far left hand side, directly under the ‘News’ tab.

Is this possible just through CSS?

Any help/guidance would be hugely appreciated.

thanks

Rob