Pure CSS Stopwatch ⏱️

Nice demo by Jhey in which he created a Pure CSS Stopwatch:

It uses a clever combination of CSS Animations, CSS Counters, and @property:

1. Each digit gets its own CSS Animation with its own timing.
2. Inside each animation the value of a CSS Counter is adjusted.
3. By defining those values as numbers using CSS @property, CSS knows how how to “animate” (read: interpolate) the values.

The animation play state is controlled using a checkbox, as detailed here.