Blocking screen at Mobile

Hi,

My website is nearly ready and I’m happy with it. I just miss one small correction: when visiting the mobile version, everything is all right at the beginning. However, as you can zoom in/out with the fingers, it everything loses proportion and the menu goes out of the screen (to the right side). It happens only after clicking on “contacto” at the side menu.

I searched on the forum and I tried several pieces of code, but I couldn’t make it work.
Help anyone?
This is my web: https://valeriaduka.com

Thanks a lot!

Miguel

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