<div></div>

div {
  display: grid;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  box-shadow: inset 0 0 10px black;
  overflow: hidden;
}

div::before {
  content: "";
/*   display: block;
  width: 200px;
  height: 200px; */
  background: conic-gradient(white 80%, transparent 80%);
  border-radius: 50%;
  filter: drop-shadow(0 0 10px black);
}

body {
  background: #dadada;
}