http://imanas.shanghai.nyu.edu/~jl9546/about-me-page-2/about-me-page-2.html
I tried the Overlay effect in my portfolio. At first the overlay was not in the middle of the page, so I adjusted the left and right padding of the container to 25% and the overlay was in the middle. also, the overlay was not the same size as my photo, so I adjusted the height. I tried to make the QR code smaller by adjusting its width and height, but failed because I found that only the height could be adjusted and the width couldn’t.