<h1 class="typing">You had me at 'hello'.</h1>

:root {
  --background-color: #212121;
  --font: sans-serif;
}

* {
  margin: 0;
  padding: 0;
}

body {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: var(--background-color);
  font-family: var(--font);
}

.typing {
  color: #fff;
  overflow: hidden;
  border-right: 0.15em solid orangered;
  white-space: nowrap;
  letter-spacing: 0.15em;
  animation: typing 3.5s steps(30, end) infinite,
    cursor-blink 0.75s step-end infinite;
}

/* The typing effect */
@keyframes typing {
  from {
    width: 0;
  }
  to {
    width: 100%;
  }
}

/* The typewriter cursor effect */
@keyframes cursor-blink {
  from,
  to {
    border-color: transparent;
  }
  50% {
    border-color: orangered;
  }
}