Bookmarklet - Convert HTML <h2> tag into foldables

gistfile1.txt

javascript:(function(){
    function wrapContentBetweenH2s() {
        const body = document.body;
        const h2s = Array.from(body.getElementsByTagName('h2'));
        
        h2s.forEach((h2, index) => {
            const details = document.createElement('details');
            const summary = document.createElement('summary');
            
            summary.innerHTML = h2.innerHTML;
            details.appendChild(summary);
            
            let nextElement = h2.nextElementSibling;
            while (nextElement && !['H1', 'H2', 'H3', 'H4', 'H5', 'H6'].includes(nextElement.tagName)) {
                const current = nextElement;
                nextElement = nextElement.nextElementSibling;
                details.appendChild(current);
            }
            
            h2.parentNode.replaceChild(details, h2);
        });
    }

    wrapContentBetweenH2s();
})();

H2 & H3

javascript:(function(){
    function wrapInDetails(el) {
        var details = document.createElement('details');
        var summary = document.createElement('summary');
        summary.style.display = 'flex';
        summary.style.alignItems = 'center';
        summary.appendChild(el.cloneNode(true));
        details.appendChild(summary);
        while (el.nextElementSibling && !['H2', 'H3'].includes(el.nextElementSibling.tagName)) {
            details.appendChild(el.nextElementSibling);
        }
        el.parentNode.replaceChild(details, el);
    }
    var headings = document.querySelectorAll('h2, h3');
    headings.forEach(wrapInDetails);
    
    var style = document.createElement('style');
    style.textContent = 'details > summary { list-style: none; } details > summary::-webkit-details-marker { display: none; } details > summary::before { content: "▶"; margin-right: 0.5em; } details[open] > summary::before { content: "▼"; }';
    document.head.appendChild(style);
})();