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

.loader {
  width: fit-content;
  font-size: 40px;
  font-family: system-ui;
  font-weight: bold;
  text-transform: uppercase;
  color: #0000;
  -webkit-text-stroke: 1px #000;
  --g: conic-gradient(#000 0 0) no-repeat text;
  background: var(--g) 0, var(--g) 100%, var(--g) 0 0, var(--g) 0 100%;
  animation: fill 2s linear infinite;
}

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

@keyframes fill {
  0%,
  100% {
    background-size: 0 100%, 0 100%, 100% 0, 100% 0;
  }

  50% {
    background-size: 55% 100%, 55% 100%, 100% 0, 100% 0;
  }

  50.01% {
    background-size: 0 100%, 0 100%, 100% 55%, 100% 55%;
  }
}