$(modal).on('transitionend', el => {
if(!document.body.classList.contains('modal-open'))
modal.classList.add('hidden');
});
$('.backdrop,.modal').each(el => document.body.appendChild(el) );
$('#solution').on('click', e => {
$(modal).on('transitionend', el => {
if(!document.body.classList.contains('modal-open'))
modal.classList.add('hidden');
});
$('.backdrop,.modal').each(el => document.body.appendChild(el) );
$('#solution').on('click', e => {