/* 背景遮罩 */
#popupOverlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
  }

  /* 隱藏用的 class */
  #popupOverlay.hidden {
    display: none;
  }

  /* 中央白色框 */
  .popup-container {
    background: #ffffff;
    padding: 16px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    max-width: 100vw;
    max-height: 100vh;
    box-sizing: border-box;
  }

  /* 圖片：寬度為可視區 80% */
  .popup-container img {
    width: 80vw;
    max-width: 100%;
    max-height: 80vh;
    height: auto;
    display: block;
    margin: 0 auto 12px auto;
  }

  /* 關閉按鈕 */
  #closePopupBtn {
    padding: 8px 16px;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 14px;
    background: #007bff;
    color: #ffffff;
  }

  #closePopupBtn:hover {
    opacity: 0.9;
  }