Timer Application Interface with Light Mode and Add Timer Function

Hello,

For quite some time, I've been unsatisfied with the built-in timers on both Android and iOS; especially for workouts, when I needed to set up a configurable number of series with rest periods in between. That's when I started thinking about building something myself. It was just a timer and I said to myself "how hard could it be?", I had no idea.

The first iteration of the project worked "just fine", but the UI was an eyesore (even more than it is now), and the UX was quite awful as well. As you can probably guess, I'm not versed in design or front-end development. In fact, my last real experience with front-end work was back when jQuery was still a thing.

However, I knew what I wanted to build, and over the last few days (and with the help of the infamous AI) I was able to wrap up the project for my needs. It required quite a lot of "hand holding" and "back and forth", but it helped me smooth out the rough edges and provided great suggestions about the latest ES6 features.

The project is, as the title states, an offline-first PWA with zero dependencies; no build step, no cookies, no links, no analytics, nothing other than timers. It uses `Web Components` (a really nice feature, in my opinion, though I still don't get why we can't easily inherit styles from the global scope) and `localStorage` to save timers between uses.

I'd appreciate any comments or suggestions, since I just want to keep learning new things.