Hi, i have tips for you :), i recomend use this html structure:
<body>
<main>
<article class="card"
</article>
</main>
</body>
If you can, don't use the width, the max-width property is better and more adaptable, try with the max-width: 350px to the card, and min-width is good too.
To separate text, divs, img, etc etc use the margin.
if you want to center the card use display:flex, justify-content:center, align-items:center, this you will center everything inside the div.
the main tag add min-height: 100vh for use all screen.
the report for more details about the accesibility.
good luck, and if you need anything I'm here to help you.
Bienvenido :3