Four Card Feature Section using Flexbox

Hey, David!

I gave mine a solid 4px with the border-top property and then assigned each one their respective color with the border-color property, like so:

.modal {
  padding: 1rem;
  margin: 1rem;
  border-top: solid 4px;
  border-radius: 4px;
  overflow: auto;
}

.modal.light-blue {
  border-color: var(--cyan);
}

.modal.red {
  border-color: var(--red);
}

.modal.yellow {
  border-color: var(--orange);
}

.modal.blue {
  border-color: var(--blue);
}

You can also check my solution's code for reference. Hope it helps.