Custom Fields table can have extra-wide checkboxes and radio buttons

[princeofabyss]

In ​Custom Fields feature, there is an unforeseeable problem in a specific CSS rule defined for div#postcustomstuff.

More specifically there is this defined in wp-admin/css/edit.css:

#postcustomstuff table input, #postcustomstuff table select, #postcustomstuff table textarea {
  width: 96%;
  margin: 8px;
}

While this works well in the situation the rule was written for, it hides a problem when attempted to reuse the code for other cases, where a checkbox or checkbox or radio button is used, as it stretches them out.

You might want to consider excluding those two from the CSS rule...

#postcustomstuff table input:not([type=checkbox]):not([type=radio]),

[sabernhardt]

With the more specific selector, that will also need to exclude the submit button. r53168 excludes more button types, and this probably could use something similar:

#postcustomstuff table input:not([type="checkbox"]):not([type="radio"]):not([type="button"]):not([type="submit"]):not([type="reset"]),
#postcustomstuff table select,
#postcustomstuff table textarea {
	width: 96%;
	margin: 8px;
}

Wrapping the exceptions inside :where() might be worth considering as well.