Check Your ageInDays by Javascript
<script type="text/javascript"> function ageInDays() { var birthYear = prompt('What year were your born ?'); var ageInDayss = (2020 - birthYear)*365; var h1 = document.createElement('h1'); var textAnswer = document.createTextNode('you are' + " "+ ageInDayss + " " + 'days old.') h1.setAttribute('id','ageInDays'); h1.appendChild(textAnswer); document.getElementById('flex-box-result').appendChild(h1); } </script> <style type="text/css"> .flex-box-container-1{ display: flex; border: 1px solid black; padding: 10px; flex-wrap: wrap; justify-content: space-around; } .flex-box-container-1 div{ /* border: 1px solid black;*/ align-items: center; padding: 10px; } .container-1{ border: 1px solid black; } </style> ...