html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
}

#chatbot-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 9999;
  background: #fff; /* Flip this if you want it dark */
}

iframe {
  width: 100%;
  height: 100%;
  border: none;
}