Hugo themes have the option to override the default rendering of Markdown images by using “Markdown Render Hooks” since version 0.62.0. By creating a file in layouts/_default/_markup named render-image.html it is possible to use a custom template for rendered images. This gives a lot of flexibility. I just used that flexibility to create a lightbox with pure CSS (without using JavaScript, like many lightbox implementations do). After clicking (or tapping) on an content image, you will see it filling the browser view.
Jan-Lukas Else
20 years old student who writes about everything he cares about.