Pros

- It's pure CSS.

Cons

- It's pure CSS.
- All links need to have a consistent dimensions for this to work
- You have to set everything up yourself in terms of telling the nav how many items there are and where the `.line` should move to whenever one of the links gets hovered.

Notes

- This uses Custom Properties, Calc, and Grid.
- While I couldn't find an easier way to make the line work with unevenly sized links, I tried my best to compensate for it by including the `--width` and `--left` custom properties, both of which would take priority over the current setup should either be defined.