.loader{display:block;--height-of-loader:4px;--loader-color:#0071e2;width:130px;height:var(--height-of-loader);border-radius:30px;background-color:rgba(0,0,0,.2);position:relative}.loader:before{content:"";position:absolute;background:var(--loader-color);top:0;left:0;width:0;height:100%;border-radius:30px;animation:moving 1s ease-in-out infinite}@keyframes moving{50%{width:100%}to{width:0;right:0;left:unset}}