MathMLElement：blur() 方法

blur()

<div>
  <math>
    <msup id="myMath" tabindex="0">
      <mi>x</mi>
      <mn>2</mn>
    </msup>
  </math>
  <button id="focusButton">Focus the Math</button>
  <button id="blurButton">Blur the Math</button>
</div>

const mathElement = document.getElementById("myMath");
const focusButton = document.getElementById("focusButton");
const blurButton = document.getElementById("blurButton");

// Focus the MathMLElement when the "Focus" button is clicked
focusButton.addEventListener("click", () => {
  mathElement.focus();
});

// Blur the MathMLElement when the "Blur" button is clicked
blurButton.addEventListener("click", () => {
  mathElement.blur();
});