test/assets/offscreenbuttons.html

<!DOCTYPE html>
<style>
  button {
    position: absolute;
    width: 100px;
    height: 20px;
  }

  #btn0 { right: 0px; top: 0; }
  #btn1 { right: -10px; top: 25px; }
  #btn2 { right: -20px; top: 50px; }
  #btn3 { right: -30px; top: 75px; }
  #btn4 { right: -40px; top: 100px; }
  #btn5 { right: -50px; top: 125px; }
  #btn6 { right: -60px; top: 150px; }
  #btn7 { right: -70px; top: 175px; }
  #btn8 { right: -80px; top: 200px; }
  #btn9 { right: -90px; top: 225px; }
  #btn10 { right: -100px; top: 250px; }
  #btn11 { right: -99.999px; top: 275px; }
</style>
<button id=btn0>0</button>
<button id=btn1>1</button>
<button id=btn2>2</button>
<button id=btn3>3</button>
<button id=btn4>4</button>
<button id=btn5>5</button>
<button id=btn6>6</button>
<button id=btn7>7</button>
<button id=btn8>8</button>
<button id=btn9>9</button>
<button id=btn10>10</button>
<button id=btn11>11</button>
<script>
  for (const button of document.querySelectorAll('button')) {
    button.addEventListener('click', () => {
      console.log(`button #${button.textContent} clicked`);
    });
  }
</script>