スライドラインで魅せるミニマルアコーディオン

<div class="accordion-slide">
  <div class="accordion-item">
    <button class="accordion-question">Q. このアコーディオンの特徴は？</button>
    <div class="accordion-answer">
      <p>A. モノトーンにラインの動きを加えた、スタイリッシュなデザインです。</p>
    </div>
  </div>

  <div class="accordion-item">
    <button class="accordion-question">Q. 複数開けますか？</button>
    <div class="accordion-answer">
      <p>A. はい、複数同時に開くことができます。</p>
    </div>
  </div>
</div>

.accordion-slide {
  max-width: 600px;
  margin: 60px auto;
  font-family: 'Helvetica Neue', sans-serif;
}

.accordion-item {
  border-bottom: 1px solid #ccc;
  position: relative;
  overflow: hidden;
}

.accordion-question {
  background: #fff;
  border: none;
  width: 100%;
  text-align: left;
  padding: 20px 20px;
  font-size: 17px;
  font-weight: 500;
  color: #222;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.accordion-question::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: #222;
  transition: width 0.3s ease;
}

.accordion-question.active::before {
  width: 100%;
}

.accordion-question::after {
  content: '+';
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  transition: 0.3s ease;
}

.accordion-question.active::after {
  content: '−';
}

.accordion-answer {
  display: none;
  padding: 18px 20px;
  font-size: 15px;
  color: #444;
  background-color: #f8f8f8;
}

document.addEventListener('DOMContentLoaded', function () {
  const questions = document.querySelectorAll('.accordion-slide .accordion-question');

  questions.forEach((btn) => {
    btn.addEventListener('click', () => {
      btn.classList.toggle('active');
      const answer = btn.nextElementSibling;
      if (answer.style.display === 'block') {
        answer.style.display = 'none';
      } else {
        answer.style.display = 'block';
      }
    });
  });
});