Twenty Twenty: Separator block does not work well with gradients

[nidhidhandhukiya]

Steps to reproduce the issue :-

1. Download WordPress version beta version.
2. Choose Twenty Twenty theme.
3. Choose separator block.
4. Apply background color to separator block.
5. Now you can able to see that background color overlaps.

Because of that design not looks as per requirements.

I have attached video for better understanding.
Video URL :- WordPress version beta version.
​https://share.cleanshot.com/Y9t7PKCBmJSB8dBW1hH4

[nidhidhandhukiya]

The reason behind this issue is :-
In block css we have the css like

    background: linear-gradient(to left, currentColor calc(50% - 16px), transparent calc(50% - 16px), transparent calc(50% + 16px), currentColor calc(50% + 16px));

If we choose any background color then the css became the below one.

background: var(--wp--preset--gradient--luminous-vivid-orange-to-vivid-red) !important;

If you check this variable inside that we have the css given below.

linear-gradient(135deg,rgba(255,105,0,1) 0%,rgb(207,46,46) 100%)

So when you compare the first and the last one that calculation is not there which we have in the first css because of that this issue is happening.

If we want to solve this issue we need to make all the css same with the calculation.

[sabernhardt]

I'm switching this to an enhancement. Gradients do not work well with the — // — double-slash styling Twenty Twenty uses, and it is not worth trying to add support for that when the theme never had its own gradients (#49711).

Maybe removing the slashes from all separators with gradients could be reasonable (front end and block editor styles):

hr.wp-block-separator[class*="-gradient-background"]::before,
hr.wp-block-separator[class*="-gradient-background"]::after {
  content: none;
}