Mobile menu is not responsive

Hello!
I found that the mobile menu increases itself and does not work properly on a mobile device when I click on the icon. How can I fix it?
my url http://shopiris.ru/
See, please my screenshot.

Hi

I think it works correctly. It only resizes to show the long name in full, but I do not think there is a different way of doing this.

There is clearly some sort of issue. Here is a screenshot from a the same device your demo and mine website. Sometimes this error leads to this result.

Hi

Ok. I've shown this to programmers and they already know this issue. Unfortunately this is an iOS related and there is no code which can be added to beat that. Simply mobile browser on iPhones is resizing site to show full width of dropdown list. This is how it was implemented.