.loader-container-preload-index {
    position: fixed;
    z-index: -1;
    width: 100vw;
    height: 100vh;
    top: 0;
    left: 0;
    background-color: #0D1117;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: Avenir, Helvetica, Arial, sans-serif;
    color: #FFF;
    flex-direction: column;
}
.loader-preload-index {
  margin: 15px;
  width: 48px;
  height: 48px;
  border: 3px solid #FFF;
  border-radius: 50%;
  display: inline-block;
  position: relative;
  box-sizing: border-box;
  animation: rotation 1s linear infinite;
}
.loader-preload-index::after {
  content: '';  
  box-sizing: border-box;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 3px solid;
  border-color: #3A7DFF transparent;
}

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