<button class='section button'>Twitter</button>
button {
  border-radius: 100%;
  padding: 10px;
  margin: 50px  
}

/* Pseudo-class */
.button:hover {
  background-color: #ff9900;
}

/* Pseudo-element */
.section::before {
  content: "6";
  padding: 1px;
  border-radius: 80%;
  position: absolute;
  background-color: red;
  width: 20px;
  height: 20px;
  top: 50px;
  left: 50px;
}

External CSS

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External JavaScript

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