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CSS

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JavaScript

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HTML 

              
                <h1>Accessible Accordion</h1>

<dl class="accordion">
  <!-- Accordion Item 1 -->
  <dt>
    <button aria-expanded="false" aria-controls="section1" id="accordion-header-1">
      What is an accessible accordion?
      <span class="accordion-icon" aria-hidden="true">▼</span>
    </button>
  </dt>
  <dd id="section1" role="region" aria-labelledby="accordion-header-1" aria-hidden="true">
    An accessible accordion is a UI pattern that allows users to expand and collapse sections of content. It follows WAI-ARIA standards to ensure it's usable for keyboard and screen reader users.
  </dd>

  <!-- Accordion Item 2 -->
  <dt>
    <button aria-expanded="false" aria-controls="section2" id="accordion-header-2">
      Why is accessibility important?
      <span class="accordion-icon" aria-hidden="true">▼</span>
    </button>
  </dt>
  <dd id="section2" role="region" aria-labelledby="accordion-header-2" aria-hidden="true">
    Accessibility ensures that users with disabilities can use and interact with web content. It promotes inclusivity and helps you comply with accessibility laws like the ADA and European Accessibility Act.
  </dd>

  <!-- Accordion Item 3 -->
  <dt>
    <button aria-expanded="false" aria-controls="section3" id="accordion-header-3">
      How do I make an accordion accessible?
      <span class="accordion-icon" aria-hidden="true">▼</span>
    </button>
  </dt>
  <dd id="section3" role="region" aria-labelledby="accordion-header-3" aria-hidden="true">
    To make an accordion accessible, use semantic HTML and WAI-ARIA attributes. Ensure proper keyboard interaction (like "Enter" and "Space" keys to toggle items), announce state changes, and maintain focus order.
  </dd>
</dl>
!

CSS 

              
                body {
  font-family: Arial, sans-serif;
  line-height: 1.5;
}

.accordion {
  border: 1px solid #ccc;
  border-radius: 5px;
  overflow: hidden;
}

.accordion dt {
  background-color: #00796b;
  color: white;
  padding: 1rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #ccc;
}

.accordion dt button {
  all: unset;
  cursor: pointer;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.accordion dt button:focus {
  outline: 3px solid #ffbf47;
}

.accordion dd {
  margin: 0;
  padding: 1rem;
  display: none;
  border-bottom: 1px solid #ccc;
}

.accordion dd[aria-hidden="false"] {
  display: block;
}

.accordion-icon {
  transition: transform 0.3s ease;
}

.accordion-icon.open {
  transform: rotate(180deg);
}
!

JS 

              
                const accordionButtons = document.querySelectorAll(".accordion dt button");

accordionButtons.forEach((button) => {
  button.addEventListener("click", () => {
    const isExpanded = button.getAttribute("aria-expanded") === "true";
    const icon = button.querySelector(".accordion-icon");
    const content = document.getElementById(
      button.getAttribute("aria-controls")
    );

    // Toggle the expanded state
    button.setAttribute("aria-expanded", !isExpanded);
    content.setAttribute("aria-hidden", isExpanded);

    // Update icon rotation
    if (!isExpanded) {
      icon.classList.add("open");
    } else {
      icon.classList.remove("open");
    }
  });

  button.addEventListener("keydown", (e) => {
    if (e.key === "Enter" || e.key === " ") {
      e.preventDefault();
      button.click();
    }
  });
});
!
999px

Console