How to translate to MyST a reST configuration involving rst_prolog role, JS and CSS?

[dbitouze]

Trying to replicate with MyST a reST configuration involving rst_prolog role, JS and CSS, I'm a bit lost between roles and substitutions.

Could someone help me to translate to MyST the following reST configuration? Thanks in anticipation.

1. My conf.py file contains:

rst_prolog = """
.. role:: latexlogo
"""

2. A source/_static/js/custom.js file contains:

window.onload = function() {
    var latexlogos = document.querySelectorAll('.latexlogo'), i, j;

    for (i = 0; i < latexlogos.length; ++i) {
        let insidelatexlogo = '';
        for (j = 0; j < latexlogos[i].innerText.length; j++) {
            if (latexlogos[i].innerText[j] !== " ") {
                insidelatexlogo += "<insidelatexlogo>";
                insidelatexlogo += latexlogos[i].innerText[j];
                insidelatexlogo += "</insidelatexlogo>";
            }
        }
        latexlogos[i].innerHTML = insidelatexlogo;
    }

};

3. A source/_static/css/custom.css file contains:

insidelatexlogo:nth-child(2) {
    text-transform: uppercase;
    font-size: 0.85em;
    vertical-align: 0.15em;
    margin-left: -0.36em;
    margin-right: -0.15em;
}

insidelatexlogo:nth-child(4) {
    text-transform: uppercase;
    font-size: 1em;
    vertical-align: -0.25ex;
    margin-left: -0.1667em;
    margin-right: -0.125em;
}

[dbitouze]

A more accurate description of my concern is here.