blinking cursor with css

Create the “cursor” with border-right:

span {
  padding: 1rem;
  border-right: 1px solid white;
}

Make it blink with an animation by removing and adding a border:

span {
  padding: 1rem;
  border-right: 1px solid white;
  animation: blink 1s linear infinite;
}

@keyframes blink {
  0% {
    border-right: none;
  }
  100% {
    border-right: 1px solid white;
  }
}