Hello. Im talking about the lesson here. Where you should insert pictures properly into html page.
I have done it and it looks just as an example, BUT i have some misunderstanding about adding responsive images. Im not quite sure it works correctly
<img srcset=“firefox-addons120.jpg 120w,
sizes="(max-width: 500px) 400px"
i have uploaded files and index html with oricinal css here on github, please check someone