3-Column Preview Card Component

Hey, nice job, card looks good.

Few suggestions:

• use cursor:pointer; on buttons.
• use border: 1px solid transparent; on buttons this prevents content shift when hovering them.

Good luck ...

Hey, great work on this one,

• The Learn more should be a link, in my opinion, using the a tag and not a button. Use the button if it will act as a control for something. But on this, it is treated as a link, go for a tag.
• For any decorative images, like in this case the icons in your cards , you should leave the alt="" and add aria-hidden=" true" or role=" presentation" to make sure that all screen readers will ignore those icons.
• Use only one h1 per page. Don't judge heading level by the weight of text given in design
• Instead of going for width try to go for max-width. Writing fixed things would cause issues.
• To overcome your accessibility issue you should need to add some semantic markers to designate sections of the page as the header, navigation, main and footer e.g:

<main>
     <div></div>
  </main>
  <footer>
</footer>

Thanks, hope it would help!