body,
html {
  height: 100%;
}
body {
  font-family: Arial, sans-serif;
  overflow: hidden;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background: #1d1d1d;
  flex-wrap: wrap;
}

.circle {
  visibility: hidden;
  width: 9vw;
  height: 9vw;
  border-radius: 50%;
  background: red;
  display: flex;
  justify-content: center;
  align-items: center;
  color: black;
  font-size: 3vw;
}