index.css

html, body {
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-family: "proxima-nova-soft", sans-serif;
  -webkit-user-select: none;
  overflow: hidden;
  background: #210202;
  /* background-image: radial-gradient(circle, #000000 0%, #ffcccc 100%); */
}

.vertical-centered-box {
  position: absolute;
  width: 100%;
  height: 100%;
  text-align: center;
}

.vertical-centered-box:after {
  content: "";
  display: inline-block;
  height: 100%;
  vertical-align: middle;
  margin-right: -0.25em;
}

.content {
  box-sizing: border-box;
  display: inline-block;
  vertical-align: middle;
  text-align: left;
  font-size: 0;
}

.loader-circle {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 120px;
  height: 120px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.1);
  margin-left: -60px;
  margin-top: -60px;
  /* border: 2px solid rgba(255, 255, 255, 0.5); */
}

.loader-line-mask {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 60px;
  height: 120px;
  margin-left: -60px;
  margin-top: -60px;
  overflow: hidden;
  transform-origin: 60px 60px;
  -webkit-mask-image: -webkit-linear-gradient(top, rgba(0, 0, 0, 1), rgba(0, 0, 0, 0));
  animation: rotate 1.2s infinite linear;
}

.loader-line {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.5);
}

@keyframes rotate {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

@keyframes fade {
  0% { opacity: 1; }
  50% { opacity: 0.25; }
}

@keyframes fade-in {
  0% { opacity: 0; }
  100% { opacity: 1; }
}

@media only screen and (max-width: 600px) {
  .loader-circle {
    width: 60px;
    height: 60px;
    margin-left: -30px;
    margin-top: -30px;
  }
  .loader-line-mask {
    width: 30px;
    height: 60px;
    margin-left: -30px;
    margin-top: -30px;
    transform-origin: 30px 30px;
  }
  .loader-line {
    width: 60px;
    height: 60px;
  }
  svg {
    width: 18px;
    height: 12px;
  }
}