Using `mix-blend-mode: difference` for line charts

[monochromer]

Fix: #15

[ai]

1. Can you show the screenshot?
2. I like --line-position idea. But let’s add block’s name prefix for BEM isolation. Something like --chart-line.

[monochromer]

let’s add block’s name prefix for BEM isolation. Something like --chart-line.

Renamed to --chart-line-position.

Screenshots:

  

[ai]

Thanks for the fix.