body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #fafafa;
  }
  
  #chat-container {
    width: 90%;
    max-width: 400px;
    height: 600px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: #fff;
  }
  
  .intro-container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
  }
  
  .kakao-ad {
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 10px 0;
    border-top: 1px solid #ccc;
  }
  
  #sex,
  #age {
    width: 200px;
    height: 30px;
    font-size: 16px;
  }
  
  #header {
    background-color: #4CAF50;
    color: #ffffff;
    padding: 16px 20px;
    text-align: center;
  }
  
  .intro-container img {
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    display: block;
  }
  
  #loader {
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 25px;
    text-align: center;
  }
  
  .loading-icon {
    font-size: 40px;
    color: #4CAF50;
  }
  
  #message-container {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    background: linear-gradient(180deg, #f9f9f9 0%, #eeeeee 100%);
    scrollbar-width: thin;
    scrollbar-color: #4CAF50 #f1f1f1;
    max-height: 400px;
  }
  
  #message-container::-webkit-scrollbar {
    width: 8px;
  }
  
  #message-container::-webkit-scrollbar-track {
    background: #f1f1f1;
  }
  
  #message-container::-webkit-scrollbar-thumb {
    background-color: #4CAF50;
    border-radius: 4px;
  }
  
  .message {
    padding: 10px;
    margin: 5px 0;
    border-radius: 18px;
    color: #333;
    line-height: 1.5;
    word-wrap: break-word;
    max-width: 70%;
  }
  
  .sent {
    background-color: #4CAF50;
    color: #ffffff;
    margin-left: auto;
    max-width: 70%;
  }
  
  .received {
    background-color: #e0e0e0;
    max-width: 70%;
  }
  
  #input-container {
    display: flex;
    border-top: 1px solid #ccc;
  }
  
  #input-container input {
    flex: 1;
    padding: 10px;
    border: none;
    border-right: 1px solid #ccc;
    outline: none;
    font-size: 16px;
    overflow-y: auto;
    max-height: 100px;
  }
  
  #input-container button {
    padding: 10px 20px;
    border: none;
    background-color: #4CAF50;
    color: #fff;
    cursor: pointer;
    font-size: 16px;
  }
  
  #input-container button:hover {
    background-color: #45a049;
  }