onmousemove = e => {
 window.last && last.forEach(a => a.style && (a.style.outline = 'none'));
 e.path.forEach((a, i, l) => a.style && (a.style.outline = (i/2) + `px solid hsl(${(i / l.length) * 360}, 100%, 50%)`));
 last = [...e.path];
}