skilled e-learning landing page Vanilla HTML & CSS

My last newbie project and still learning. Any feedback welcomed, particularly regards using img srcset

I tried to do a more complex img tag for the fallback for picture/source but couldn't get it to work. This was what I was trying to do

<img src="assets/logo-dark.svg" srcset="
        assets/image-hero-mobile.png 435w,
        assets/image-hero-tablet.png 695w,
        assets/image-hero-desktop.png 1046w" sizes="
              (max-width: 767px) 87vw,
              (max-width: 1439px) 83vw,
              (max-width: 2000px) 870px,
              1000px"
          class="">

in the end I just went with a simpler one with the mobile image at 1x and 2x.