menu on mobile

Hello
I am having a problem with menu/navigation on my blog
http://www.kokardowakraina.pl

The menu/navigation on top is visible and functional on computer screens but on the other mobiles it just shows the background color and no clickable links to navigate the website.

I have tried to add code from comment 4. from https://wordpress.org/support/topic/menu-items-not-visible-on-mobile-devices-cant-navigate?replies=7
but it didn’t help for me.

Could You please look on my blog and tell me what should I do? (I am not experience programer in wordpress).

Thank you
Martin