RFR: 8318416: Superscript marks should use consistent font style

[Chen Liang]

On Tue, 26 Nov 2024 15:50:54 GMT, Hannes Wallnöfer <hannesw at openjdk.org> wrote:

> Please review a change to use consistent styles for the `PREVIEW` and `RESTRICTED` superscript labels in API docs. Previously, these labels inherited font style properties from their containing element, such as bold font in summary table links, or serif font in links contained in description text (see attached screenshots). 
> 
> With this change, superscript labels always use normal weight monospace font. Additionally, they now have a light gray background to make them easier to distinguish from surrounding text and give them a tag-like appearance.
> 
> Before / after screenshots:
> 
> <img width="773" alt="preview-summary-old" src="https://github.com/user-attachments/assets/fbb4e325-f706-4b54-88cd-34c207a2de25">
> 
> <img width="766" alt="preview-summary-new" src="https://github.com/user-attachments/assets/9cbe490d-0444-4c4f-a1f6-004754552166">
> 
> I also cleaned up the styles for `<sup>` elements in other contexts. Where the content of `<sup>` was previously [too big] or [too small] it now uses the browser default again. 
> 
> [too big]: https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/lang/Math.html#scalb(double,int)
> [too small]: https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/lang/Math.html#expm1(double)
> 
> Sorry if the diff is a bit more complex than necessary, I reformatted the code that generates the labels when adding the `HtmlStyles` argument. I also removed 3 unused `<table>`-related methods from `HtmlTree` that are not likely to be needed again.

Looks good. In fact, the style inconsistency is manifest in the header: https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/lang/classfile/CodeBuilder.html

Another thing of note is that the classes in nested class summary has a preview superscript marker, but not so for methods or fields in their respective summary sections.  We can look into that later.

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Marked as reviewed by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22393#pullrequestreview-2462336312