CSS

Replace<div class="card">with the main, <p class="main-text"> with <h1> tag and <div class="attribution"> with the footer tag to fix the accessibility issues. click here for more on web-accessibility and semantic html

Every html must have <h1> to make it accessible. Always begin the heading of the html with <h1> tag wrap the sub-heading of <h1> in <h2> tag, wrap the sub-heading of <h2> in <h3> this continues until <h6>, never skip a level of a heading.

To center .card on the page using grid, replace the height in the body with min-height: 100vh.

For a responsive content, replace the width in .card with max-width.

Hope am helpful.

Well done for completing this challenge. HAPPY CODING