body {
  height: 100vh;
  overflow: hidden;
  display: grid;
  place-items: center;
}

.loader {
  width: fit-content;
  padding-bottom: 5px;
  font-weight: bold;
  font-family: monospace;
  font-size: 30px;
  overflow: hidden;
  color: #0000;
  text-shadow: 0 0 0 #000, 10ch 0 0 #000;
  background: linear-gradient(#000 0 0) bottom left/0% 3px no-repeat;
  animation: loading 1.5s infinite;
}

.loader::before {
  content: "Loading...";
}

@keyframes loading {
  80% {
    text-shadow: 0 0 0 #000, 10ch 0 0 #000;
    background-size: 100% 3px;
  }

  100% {
    text-shadow: -10ch 0 0 #000, 0 0 0 #000;
  }
}