mathvariant=Monospace produces bold letters

Issue Summary

The mathvariant="monospace" mtext renders the letters in a bolder fashion, making them stand out and prone to be misinterpreted as intentionally bold letters, e.g. vector notations.

Steps to Reproduce:

Add the following mathML inside math> mrow > mtable > mtr > mtd > mstyle
<msub> <mrow> <mtext mathvariant="monospace">SN</mtext> </mrow> </msub>

Technical details:

• MathJax Version: 4.1.2
• Client OS: Mac OS 26.3.1
• Browser: Chrome, Build 147.0.7727.138

I am using the following MathJax configuration:

         ...  
        displayOverflow: 'linebreak',
        font: 'mathjax-tex',
        mathmlSpacing: true,
        linebreaks: {
          inline: true,
          width: /Firefox/.test(navigator.userAgent) ? '40%' : '90%',
          lineleading: 0.2,
          LinebreakVisitor: null,
        },
      }

and loading MathJax via

<script src="'https://cdn.jsdelivr.net/npm/mathjax@4.1.2/mml-chtml.js"></script>

Supporting information:

In the following equation the letters SN, TN and Lick are all monospace.

Link to live article: https://elifesciences.org/articles/95802

Start with the supplied MathML reproduction and the mml-chtml.js entry point used in MathJax 4.1.2, then trace how mathvariant="monospace" selects and renders the CHTML font. Confirm the result against the reported SN, TN, and Lick examples; done means monospace letters no longer appear unintentionally bold while remaining monospace.