I've been using Firefox as my main browser for a long time and over the past couple of years I noticed an uptick in websites that wouldn't work lest I used Chromium. For instance last week I had to use a crappy HSBC website that wouldn't let me login in Firefox (it would just hang) while it worked in Chromium.
It's still very minor and I can't even come up with a 2nd example off the top of my head but it does definitely happen from time to time.
If anything these few cases only makes me value Firefox even more, I don't want to enable the Chrome monopoly.
The site looks pretty nice.
I have no experience in web design, so no real technical input from my side, but I noticed it is inconsistent with the time representation.
You use the 12-hour AM/PM representation in the "I have to wake up at..." picker and in your text below that.
But the actual calculated bed time uses the (imo better) 24-hour format. This could lead to confusion, but at least is somewhat inconsistent.