.loader {
    margin: var(--padding);
    width: 45px;
    aspect-ratio: .75;
    --c: no-repeat linear-gradient(var(--page-content-title-bkg-color) 0 0);
    background: 
        var(--c) 0%   50%,
        var(--c) 50%  50%,
        var(--c) 100% 50%;
    background-size: 20% 50%;
    animation: l6 1s infinite linear;
}

@keyframes l6 {
  20% {background-position: 0% 0%  ,50% 50% ,100% 50% }
  40% {background-position: 0% 100%,50% 0%  ,100% 50% }
  60% {background-position: 0% 50% ,50% 100%,100% 0%  }
  80% {background-position: 0% 50% ,50% 50% ,100% 100%}
}