vering over the system selector
            selector.addEventListener('mouseover', e => {
                [...document.querySelectorAll('.summary-row')].map(row => {
                    row.className = row.dataset.system == elem ? 'summary-row summary-row-hilite' : 'summary-row' });
                [...document.querySelectorAll('.th-entry')].map(th => {
                    th.className = th.dataset.system == elem ? 'th-entry th-entry-hilite' : 'th-entry' });
            });
            selector.addEventList