 summary ~ ul li:nth-child(2):before {
animation:grow .5s ease-in-out normal forwards;
animation-delay:.2s;
}

details[open] summary ~ ul li:nth-child(3) div,details[open] summary ~ ul li:nth-child(3) div:before {
animation:sweep .5s ease-in-out normal forwards;
animation-delay:.2s;
}

details[open] summary ~ ul li:nth-child(3):before {
animation:grow .5s ease-in-out normal forwards;
animation-delay:.3s;
}

details[open] summary ~ ul li:nth-child(4) div,details[open] summary ~ ul li:nth-child(4) div:before 