My 2nd project- Survey Form. Please give a feedback

Hi there. This is my 2nd project: https://codepen.io/lElfenLiedl/full/eYObrZm.
I would appreciate any feedback on this, what should i improve.

Also i have a question:
When i open this page on mobile device checkboxes change their size and look ugly(the more text in a label the smaller checkbox size). How can i fix this?