.box{--border-angle:0deg;display:flex;justify-content:center;align-items:center;animation:border-angle-rotate 4s linear infinite;border:5rem solid transparent;position:relative;&.b{background:conic-gradient(from var(--border-angle),var(--bg) 50%,white) border-box}}@keyframes border-angle-rotate{0%{--border-angle:0deg}to{--border-angle:360deg}}.orbit{--bg:hsl(0,0%,0%);background:var(--bg)}@property --border-angle{syntax:"<angle>";initial-value:0deg;inherits:false}