#splash {
 display: flex;
 flex-direction: column;
 align-items: center;
 justify-content: center;
 height: 100vh;
}

#splash .loader {
 margin: 0 auto;
 width: 100px;
 height: 100px;
 border-radius: 50%;
 background:
  radial-gradient(farthest-side, #000 94%, transparent) top/16px 16px no-repeat,
  conic-gradient(transparent 30%, #000);
 -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 16px), #000 0);
 animation: loader 1s infinite linear;
}

@keyframes loader {
 100% {
  transform: rotate(1turn);
 }
}