I looked into it and this turned out to be the problem exactly.
If you change the part of your code where you have
hsl(${i*120} 99%${K*99}%
To instead
hsl(${i*120} 99% ${K*99}%
(That is, by not omitting the space after 99%)
Then it works in the versions of Safari that I tested; Safari 14.0.3 on macOS Big Sur 11.2.2 running on a MacBook Pro M1, and Safari on iOS 14.4 running on an iPhone X.
Comments
I looked into it and this turned out to be the problem exactly.
If you change the part of your code where you have
To instead (That is, by not omitting the space after 99%)Then it works in the versions of Safari that I tested; Safari 14.0.3 on macOS Big Sur 11.2.2 running on a MacBook Pro M1, and Safari on iOS 14.4 running on an iPhone X.