当你 checkout Bootstrap 5 accordion时，你会看到一个轮廓。我想删除它。我不确定是哪个元素实际上产生了轮廓，但我怀疑是button。无论如何，我已经尝试将以下内容应用于所有可能的元素：

.accordion-item, .accordion-item:focus, .accordion-item:active,
.accordion-header, .accordion-header:focus, .accordion-header:active,
.accordion-button, .accordion-button:focus, .accordion-button:active {
  outline: none !important;
}

好像什么都不管用。有什么办法吗？
下面是html代码的副本：

<div class="accordion" id="accordionExample">
  <div class="accordion-item">
    <h2 class="accordion-header" id="headingOne">
      <button class="accordion-button" type="button" data-bs-toggle="collapse" data-bs-target="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
        Accordion Item #1
      </button>
    </h2>
    <div id="collapseOne" class="accordion-collapse collapse show" aria-labelledby="headingOne" data-bs-parent="#accordionExample">
      <div class="accordion-body">
        ...
      </div>
    </div>
  </div>
</div>