function calculateYearsSince(dateString) {
    const date = new Date(dateString);
    const diff = Date.now() - date.getTime();
    return new Date(diff).getUTCFullYear() - 1970;
}

console.log(calculate2("2001-09-01"));

const form = document.getElementById('hogwarts-form');
form.dateofbirth.addEventListener("input", function(event){
    console.log(form.dateofbirth.value);
    const age = calculateYearsSince(form.dateofbirth.value);
    console.log(age);

    if(age >= 11){
        form.dateofbirth.setCustomValidity('');
    }else{
        form.dateofbirth.setCustomValidity('young');
    }
})

form.house.addEventListener('change', function (event){
    const houseColor = form.house.options[form.house.selectedIndex].dataset.colorPrimary;
    console.log(houseColor);
    document.body.style.backgroundColor = houseColor;
})