Apply WCAG 2.5.8 (24px min hit target) consistently across small controls

[ravisuhag]

Summary

Several interactive controls render below the WCAG 2.5.8 (Target Size, Minimum — 24×24px) threshold. An earlier attempt (commit b3ab3bcb) added transparent ::before pseudo-elements to pad the hit boxes, but it was reverted because the 24px rule was applied unevenly and left gaps. This issue tracks doing it consistently.

Sub-24px controls today

Control	Size(s) below 24px
checkbox	.small 12px, .large 16px
radio	.small 12px, default 16px
icon-button	size-1 12px, size-2 16px, size-3 20px
toggle	size-1 12px, size-2 16px
slider	small thumb 8×16px
chip	dismiss button ~12px
callout	dismiss ~20px
color-picker	thumbs (small)
sidebar handle	4px

(space-4 = 12px, space-5 = 16px, space-6 = 20px, space-7 = 24px.)

Problems with the reverted attempt

1. Inconsistent threshold. icon-button and toggle expanded both their 12px and 16px sizes; checkbox and radio expanded only 12px, leaving the 16px .large checkbox and 16px default radio untouched. Same pixel size, different treatment.
2. 20px controls left as-is. icon-button size-3 (20px) and callout dismiss (20px) still fall under 24px — they pass only via WCAG's spacing exception, not the minimum.
3. Coverage gaps. chip dismiss (~12px) and color-picker thumbs were never touched.
4. Grouped-toggle clip. Inside .group (overflow: clip, 1px gaps) the ::before expansion is clipped at the group edge, so the fix is partly defeated there.

Suggested approach

• Decide the policy explicitly: expand every interactive target below 24px, or rely on the spacing exception for ≥20px targets and document that. Then apply it uniformly.
• If checkboxes/radios are exempt because they sit inside a clickable label, state that and skip their box expansion entirely (don't expand only the 12px variant).
• Consider a shared pattern for the pseudo-element expansion — a --rs-space-7 (24px) named min-target with the inset derived via calc() — to avoid repeating magic insets (-6 / -4 / -8) across five files.
• Resolve the grouped-toggle clipping (e.g. rethink the group's overflow, or accept and document the limit).

Notes

The mechanism itself (transparent absolutely-positioned ::before, position: relative host, layout/visuals unchanged) was correct and the per-size math was right — the issue is scope/consistency, not technique.