Modal / 22 ミニマルフルスクリーン｜Minimal Fullscreen

<!-- モーダルを開くボタン -->
<button class="modal-button">Minimal Fullscreen Modal</button>

<!-- モーダルの背景マスク -->
<div class="mask"></div>

<!-- モーダル本体（フルスクリーン対応クラスを追加） -->
<div class="modal fullscreen">
  <div class="modal-content">
    <div class="close-btn-container">
      <button class="close-btn">×</button>
    </div>
    <div class="fullscreen-content">
      <p>【Minimal Fullscreen Modal】</p>
      <p>シンプルで清潔感のあるフルスクリーンモーダルです。</p>
      <p>ESCキーでも閉じることができます。</p>
      <div class="close-btn-container">
        <button class="close-btn">CLOSE</button>
      </div>
    </div>
  </div>
</div>

/* 開くボタンのスタイル */
.modal-button {
  padding: 15px 30px;
  background: #f8f9fa;
  color: #495057;
  border: 2px solid #dee2e6;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.modal-button:hover {
  background: #e9ecef;
  border-color: #adb5bd;
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

/* 背景マスクスタイル */
.mask {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.mask.appear {
  opacity: 1;
  visibility: visible;
}

/* フルスクリーンモーダル本体 */
.modal.fullscreen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #ffffff;
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal.fullscreen.appear {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* 右上が絶対配置で「×」ボタン */
.modal.fullscreen > .modal-content > .close-btn-container {
  position: absolute;
  top: 20px;
  right: 20px;
  z-index: 10;
}

.modal.fullscreen > .modal-content > .close-btn-container .close-btn {
  width: 40px;
  height: 40px;
  background: rgba(0, 0, 0, 0.1);
  color: #495057;
  border: none;
  border-radius: 50%;
  font-size: 24px;
  font-weight: 300;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.modal.fullscreen > .modal-content > .close-btn-container .close-btn:hover {
  background: rgba(0, 0, 0, 0.2);
  transform: scale(1.1);
}

/* モーダルコンテンツ中央揃え */
.fullscreen-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 40px;
  text-align: center;
}

.modal p {
  color: #6c757d;
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: 20px;
  max-width: 600px;
}

/* 下部の「CLOSE」ボタン */
.fullscreen-content .close-btn-container {
  margin-top: 30px;
}

.fullscreen-content .close-btn {
  padding: 12px 30px;
  background: #495057;
  color: #ffffff;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-block;
  min-width: 120px;
}

.fullscreen-content .close-btn:hover {
  background: #343a40;
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

(function () {
  var btn = document.querySelector('.modal-button');
  var mask = document.querySelector('.mask');
  var modal = document.querySelector('.modal');
  var closeBtns = document.querySelectorAll('.close-btn');

  if (!btn || !mask || !modal) return;

  function openModal() {
    mask.classList.add('appear');
    modal.classList.add('appear');
    if (modal.classList.contains('fullscreen')) {
      document.body.style.overflow = 'hidden';
    }
  }

  function closeModal() {
    mask.classList.remove('appear');
    modal.classList.remove('appear');
    if (modal.classList.contains('fullscreen')) {
      document.body.style.overflow = '';
    }
  }

  btn.addEventListener('click', openModal);
  mask.addEventListener('click', closeModal);
  closeBtns.forEach(function(b) { b.addEventListener('click', closeModal); });

  document.addEventListener('keydown', function (e) {
    if (e.key === 'Escape' && modal.classList.contains('appear')) {
      closeModal();
    }
  });
})();