Using css flex box

Replace <div class="card"> with the main tag, <h2> with <h1> and <h4> with <h2> to fix the accessibility issue. click here for more on web-accessibility and semantic html

Use rem or em as unit for the padding, margin, width and preferably rem for the font-size for more on CSS units click here

To center .container on the page, add min-height:100vh; display: flex; align-items: center: justify-content: center; or min-height:100vh; display: grid place-items: center to the body.

There is no need for the height in . card, increase the padding value for the .top-card, .left-card and the right-card.

the body has a wrong background-color. give the box-shadow of .card a color value of rgba(0,0,0,0.15)

Hope am helpful.

Well done for completing this challenge. HAPPY CODING