<div class="block"> <div class="box"> </div> </div>
.block{ height: 100vh; display: flex; align-items: center; justify-content: center; overflow: hidden; } .box{ width: 60vmin; height: 60vmin; border: 1px dashed rgba(255, 255, 255, 0.4); position: relative; background:#000; border-radius:30% 70% 40% 60%; }