.btn-loader,.loader20 {
    /* --s: 54px; */
    --s: 45px;
    width: var(--s);
    aspect-ratio: 2;
    --_g: #ffffff 90%, #0000;
    background: radial-gradient(farthest-side,var(--_g)) 0   50%/25% 50%,
      radial-gradient(farthest-side at bottom,var(--_g)) 50%  calc(50% - var(--s)/16)/25% 25%,
      radial-gradient(farthest-side at top   ,var(--_g)) 50%  calc(50% + var(--s)/16)/25% 25%,
      radial-gradient(farthest-side at bottom,var(--_g)) 100% calc(50% - var(--s)/16)/25% 25%,
      radial-gradient(farthest-side at top   ,var(--_g)) 100% calc(50% + var(--s)/16)/25% 25%;
    background-repeat: no-repeat;
    animation: l14 1s infinite;
    margin: 5px auto;
}
.loader20{
  --s: 65px;
  --_g: #0e0d0d 90%, #0000;
}

  @keyframes l14 {
      25%  {background-position:0    50%,50% 0,50% 100%,100% 0,100% 100%}
      50%  {background-position:100% 50%,0   0,0   100%,50%  0,50%  100%}
      75%,
      100% {background-position:100% 50%,0 calc(50% - var(--s)/16),0 calc(50% + var(--s)/16),50% calc(50% - var(--s)/16),50% calc(50% + var(--s)/16)}
  }