.certificate-popup {
    display: none;
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    z-index: 9999;
    overflow: auto;
  }

  .popup-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    width: 90%;
    max-width: 600px;
    position: relative;
    height: 600px;
    overflow: auto;
  }

  .close-btn {
    position: absolute;
    right: 15px;
    top: 10px;
    color: #555;
    font-size: 24px;
    font-weight: bold;
    cursor: pointer;
    z-index: 10000;
  }

  .close-btn:hover {
    color: #000;
  }