作者姓名: Yuan Huang

// html

<div class="accordion-container">
  <input type="checkbox" id="chkbox-1" class="chkbox" />
  <label class="accordion-title" for="chkbox-1">...</label>
  <div class="accordion-content">
    <div>
      <p class="mb-3">...</p>
      <p class="mb-3">...</p>
      <p>...</p>
    </div>
  </div>
</div>

// css

*,
*::before,
*::after {
  box-sizing: border-box;
}

.accordion-list {
  max-width: 640px;
  margin: 0 auto;
  padding: 0.25rem;
}

.chkbox {
  display: none;
}
.chkbox:checked ~ .accordion-title::after {
  content: '\F2EA';
}
.chkbox:checked ~ .accordion-content {
  grid-template-rows: 1fr;
}

.accordion-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0 1rem 0;
  font-weight: bold;
  font-size: 1.2rem;
  cursor: pointer;
}
.accordion-title::after {
  font-family: bootstrap-icons;
  content: '\F4FE';
}

.accordion-content {
  display: grid;
  grid-template-rows: 0fr;
  transition: 0.4s ease-in-out;
}
.accordion-content > div {
  overflow: hidden;
}
.accordion-content p {
  margin: 0;
}

p.mb-3 {
  margin-bottom: 1rem;
}

Demo