body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    margin: 0;
    padding: 0;
  }
  
  #openModalBtn {
    display: block;
    width: 120px;
    height: 40px;
    margin: 20px auto;
    background-color: green;
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
  }
  
  #modalContainer {
    display: block;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.4);
  }
  
  #modalContent {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 90%;
    max-width: 400px;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    text-align: center;
  }
  
  #closeModalBtn {
    position: absolute;
    top: 10px;
    right: 10px;
    font-size: 24px;
    color: #888;
    cursor: pointer;
  }
  
  h2 {
    font-size: 20px;
    margin-bottom: 20px;
  }
  
  textarea {
    width: 100%;
    height: 120px;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    resize: none;
    font-size: 16px;
    margin-bottom: 20px;
  }
  
  #sendBtn {
    display: block;
    width: 100%;
    max-width: 200px;
    height: 40px;
    margin: 0 auto;
    background-color: green;
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
  }
  
  @media (max-width: 480px) {
    #modalContent {
      width: 90%;
      max-width: 300px;
    }
  }