Portfolio Help and Feedback Needed

Hi guys - my first post on here.

I have just gone back and re-done my personal portfolio page; check it out here: https://dkeen0123.github.io/PersonalSite/

Id love some feedback on a few things if anyone has the answers:

  1. I have used mixins to make the page responsive, and when I manually shrink my browser, everything seems fine - the header nav bar changes into a hamburger etc. However when I use chrome dev tools on my browser or go to the page on my phone, it doesn’t have the correct layout - am I missing something?

  2. Any help and feedback on styling/ colour scheme would be appreciated. I don’t particularly like the title stylings, and whilst the polaroid effect on the portfolio is cool, I don’t know if it fits in. Any opinions and suggestions welcome!

Thanks in advance for any feedback - and please do be as detailed and critical of my code as you like! I want to make this as good as possible.