Unicode does not specify any fonts, though many fonts are defined to be consistent with the Unicode standard, nevertheless they are emphatically not part of Unicode.

How symbols including diacritics are drawn and displayed is not a concern for Unicode, different fonts can interpret 'filled circle' or the weight of a glyph as they like, just as with emoji. By convention they generally adopt common representations but not entirely. For example try using the box drawing characters from several different fonts together. Some work, many don't.

You can say things like "", "", "", "" and "" which are all Unicode are not technically "fonts" but it's a distinction without a meaningful difference.