fix(button): fix base box-shadow styling

[dancormier]

The recent refactor of button styling introduced a bug where an inner box shadow was set on the base button styling. This was an unintended change and, since these buttons featured a transparent background, the box shadow would create a rather unpleasant style.

This PR fixes this styling bug. Once merged, I'll cut a new patch release.

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Thanks for the report @abovedave! I've added you as a reviewer for this. Can you take a peek at the deploy preview and let me know if the box shadows render for you as expected?

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[abovedave]

Fixed the base button, but I'm wondering if it needs moving into the &.s-btn__filled modifier for danger and muted as well @dancormier?

Stacks/lib/css/components/buttons.less

Line 230 in c75943a

--_bu-bs: inset 0 var(--su-static1) 0 0 hsla(0, 0%, 100%, 0.4);

Stacks/lib/css/components/buttons.less

Line 271 in c75943a

--_bu-bs: inset 0 var(--su-static1) 0 0 hsla(0, 0%, 100%, 0.4);

[abovedave]

Should the alpha for those be 0.7 instead of 0.4 as well?

[dancormier]

Should the alpha for those be 0.7 instead of 0.4 as well?

My goal with the button CSS refactor was to maintain styles as-is while cleaning up the structure and cascade. The box shadow for the base filled button has 0.7 as the alpha value, while the danger and muted filled variants both use 0.4, so I've left them in tact. I'm assuming this was intended to unify the look of that box shadow across button variants (since the base style background color is lighter and requires a more opaque shadow to contrast with it) but I'm not 100% sure of the reasoning.