Audit and review new CSS Standards

[endigo9740]

CSS standards continue to improve and expand. We should have a due diligence path investing any features that might be relevant to Skeleton users.

NOTE: that minimal browser requirements should be reviewed before moving forward on these features

References

• Adam Argyle video: https://www.youtube.com/watch?v=QW6GECIzvsw

Ideas

• view-transitions for our docs, animation patterns, etc
• field-sizing: content - applicable to most form inputs ([MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/field-sizing))
• @property - type checking for CSS custom properties ([MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/@property))
• Add <hr> within select > option menus
• Use the <search> element to wrap search forms ([MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/search))
• Inputs: :user-{valid|invalid} for better form validation states ([MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/:user-invalid))
• <details> supports name attribute to close auto-close panels ([MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/details#name))
• (review Responsive color section in detail - lots of goodies)

Requirements

Determine what features we wish to support and document them in this ticket or as sub-tasks items.