<div class="start"> <div></div> </div>
.start { width: 80vmin; height: 80vmin; margin: 10vmin; } div { position: absolute; left: 0; top: 0; width: 50%; height: 50%; background-color: rgba(255,255,203,.2); border-radius: 50%; animation: spin 10s linear infinite; } @keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }