body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  background: #f0f0f0;
}

.circulo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: conic-gradient(
    rgba(52, 152, 219, 0.3) 0deg 60deg,      /* celeste semitransparente */
    transparent 90deg 180deg,
    rgba(52, 152, 219, 0.2) 180deg 270deg,
    transparent 270deg 360deg
  );
}