.loader{width:45px;aspect-ratio:1;--c:no-repeat linear-gradient(#000 0 0);background:var(--c) 0 0,var(--c) 0 100%,var(--c) 50% 50%,var(--c) 100% 0,var(--c) 100% 100%;animation:l13 1s infinite alternate;margin:0 auto}@keyframes l13{0%,10%{background-size:20% 100%}50%{background-size:20% 20%}90%,to{background-size:100% 20%}}