UI issue: no way to edit markdown link in mobile/responsive view when editing event.
I have noticed this both on a chromium based browser on a mobile device, and on firefox on linux with a mobile-size browser window.
When creating/editing an event, there is no way to enter the URL for a markdown link. to access the Link button on the toolbar, one scan scroll to the right. Firstly, this is fairly unintuitive on mobile, there may be a better way to display all the toolbar options or make it obvious they are there. But the actual issue is that even scrolling to the end, the text bar where one would enter the URL will not appear. The viewport/window needs to be wider than the entire length of the toolbar, not counting the URL textbox, for the textbox to appear.
A crude workaround on mobile is to turn your phone sideways, and then the text box for the URL will appear.