This website is created using HTML5 and CSS3, Here I made it with a little bit of javascript and already responsive design for mobile and desktop, that every button is clicked automatically it will turn dark, otherwise if you click it again it will return to the default color (white).
const btnForTheme = document.getElementById('lightbtn');
//if clicked
btnForTheme.addEventListener('click', function () {
document.body.classList.toggle('dark-theme');
});
And here for design card, my inspiration from dribbble.
