This selector is for the location and the size of the indicator - Change these for different location and size of the indicator (Keep the size in 1:1 ratio).
These selectors are for the 2 halves with `overflow:hidden` - Do not change these.
This combined with `.left` & `.right` are for the actual border - Change border color of these for a different circle color.
The videos Kurzgesagt channel creates are so beautifully animated, that I almost forget that I learn so much while watching them!