Responsive Columns using CSS Grid

HTML:

• Every webpage needs a <main> that wraps all of the content, except for <header> and footer>. This is vital for accessibility, as it helps screen readers identify the "main" section of a page. Change .main to a <main>.

• There should only be one <h1> on a page. Given there are 3 similar headings, I would change all of them into a <h2>.

CSS:

• It's good practice to include a CSS Reset at the top.

• Add around 1rem of padding on the body, so the card container doesn't touch the edges on small screens.

• Remove font-optical-sizing and font-style.

• On body and .main, change height to min-height.

• Remove the fixed width on the card container. Instead, add a max-width in rem.

• font-size must never be in px. This is a big accessibility issue, as it prevents the font size from scaling with the user's default setting in the browser. Use rem instead.

• It is common to do mobile styles as the default and use media queries (in rem) for larger screens.