Notice there is only 1 full headline (from /r/NoStupidQuestions) visible, it doesn’t even show the full post. There are 3 of those “trending” boxes but only 2 of those even fit their headlines because they are like 3 words long, they cut off anything longer including the description
I originally became addicted to Reddit because of how streamlined it was to skim dozens of headlines and pick from lots of content, seems they have decided content is not something they want to provide anymore :/
Responsive design is approach you can use as part of your mobile first development. There are others, but responsive is a good one.