body {
    font-family: 'Poppins', sans-serif;
    background: #f4f9ff;
    margin: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
  }
  header {
    background: #0077ff;
    color: white;
    padding: 1rem 2rem;
    text-align: center;
    font-weight: 600;
    font-size: 1.5rem;
  }
  .chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    max-width: 600px;
    margin: 1rem auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 8px 18px rgba(0,0,0,0.1);
    overflow: hidden;
  }
  .messages {
    flex: 1;
    padding: 1rem;
    overflow-y: auto;
    background: #e9f0ff;
  }
  .message {
    max-width: 80%;
    margin-bottom: 1rem;
    padding: 0.7rem 1rem;
    border-radius: 18px;
    font-size: 0.95rem;
    line-height: 1.3;
  }
  .message.user {
    background: #0077ff;
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 2px;
  }
  .message.bot {
    background: #e0e0e0;
    color: #333;
    align-self: flex-start;
    border-bottom-left-radius: 2px;
  }
  form {
    display: flex;
    border-top: 1px solid #ccc;
  }
  input[type="text"] {
    flex: 1;
    border: none;
    padding: 1rem;
    font-size: 1rem;
    border-radius: 0 0 0 12px;
    outline: none;
  }
  button {
    background: #0077ff;
    border: none;
    color: white;
    padding: 0 1.5rem;
    font-weight: 600;
    cursor: pointer;
    font-size: 1rem;
    border-radius: 0 0 12px 0;
    transition: background 0.3s;
  }
  button:hover {
    background: #005fcc;
  }

  /* Scrollbar style */
  .messages::-webkit-scrollbar {
    width: 6px;
  }
  .messages::-webkit-scrollbar-thumb {
    background-color: #0077ff;
    border-radius: 3px;
  }
  @media (max-width: 600px) {
    .chat-container {
      margin: 0.5rem;
      height: 100vh;
      max-width: 100%;
      border-radius: 0;
    }
  }