There is a solution without resorting to JS libraries or CSS hacks. If you bold the characters, they become slightly larger, making the distinction between . and , more obvious.
Normal vs. bold:
If you want, you can use something like this:
Here's an in-line comparison: ,
Here's the code:
<sub><sub><img src="http://i.stack.imgur.com/Lrzd0.png" alt=","></sub></sub>
Why <sub> twice? Here's why: (it isn't in the same line!)
The image is a png with exactly 261 bytes. Here's it in base64:
This happens because the font size for <code> tags is specified as a fixed pixel value:
The normal font size for plain text on this site is 15px, so replacing the CSS rule above with:
would let the font size of <code> elements scale up in headers, while keeping the font size of code in plain text the same ...