Bug in Javascript with your ‘details elements’ helper

Your codeblock here, has a slight bug

// from 
// open closed details elements for printing
window.addEventListener('beforeprint',() =>
{
    const allDetails = document.body.querySelectorAll('details');
    for(let i=0; i<allDetails.length; i++) { if(allDetails[i].open) { allDetails[i].dataset.open = '1'; } else { allDetails[i].setAttribute('open', ''); } } }); // after printing close details elements not opened before window.addEventListener('afterprint',() =>
{
    const allDetails = document.body.querySelectorAll('details');
    for(let i=0; i<allDetails.length; i++)
    {
        if(allDetails[i].dataset.open)
        {
            allDetails[i].dataset.open = '';
        }
        else
        {
            allDetails[i].removeAttribute('open');
        }
    }
});

It should look like

window.addEventListener('beforeprint',() =>
{
    const allDetails = document.body.querySelectorAll('details');
    for(let i=0; i<allDetails.length; i++) {
        if(allDetails[i].open) {
            allDetails[i].dataset.open = '1'; 
        } else {
            allDetails[i].setAttribute('open', '');
        } 
    } 
}); // after printing close details elements not opened before 
window.addEventListener('afterprint',() =>
{
    const allDetails = document.body.querySelectorAll('details');
    for(let i=0; i<allDetails.length; i++)
    {
        if(allDetails[i].dataset.open)
        {
            allDetails[i].dataset.open = '';
        }
        else
        {
            allDetails[i].removeAttribute('open');
        }
    }
});

In the process of smashing the first window.addEventListener into one line, you inadvertently included the *second* window.addEventListener into the comment preceding it