<span></span>
span {
  position: relative;
  width: 10px;
  height: 10px;
  display: block;
  background-color: #000;
  border-radius: 50%;
  cursor: pointer;
}

span:hover::after {
  content: "";
  position: absolute;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 2px solid #000;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

External CSS

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External JavaScript

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