<h1>Optgroup example</h1>

<form>
  <label for="animal-select">Choose an animal:</label>
  <select id="animal-select">
      <optgroup label="Mammals">
          <option>Dog</option>
          <option>Cat</option>
          <option>Mouse</option>
      </optgroup>
      <optgroup label="Reptiles">
          <option>Snake</option>
          <option>Lizard</option>
          <option>Crocodile</option>
      </optgroup>
      <optgroup label="Birds">
          <option>Owl</option>
          <option>Eagle</option>
          <option>Raven</option>
      </optgroup>
  </select>
</form>
*{font-family: arial}

body {
  display: flex;
  justify-content: center;
  flex-direction: column;
  align-items: center;
}

h1 {
  text-align: center;
}

form {
  max-width: 500px;
  padding: 20px;
  box-shadow: 0px 0px 16px 4px rgba(0,0,0,0.1)
}


label {
  margin: 0 0 4px 0;
}

select {
  padding: 4px 10px;
  font-size: 16px;
  border-radius: 4px;
  border: 1px solid #ccc;
}

External CSS

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External JavaScript

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