body { font-family: Arial, sans-serif; background:#bf6759; }
#chat {
  width: 100%;
  max-width: 700px;
  margin: 20px auto;
  background:#fff;
  border-radius:10px;
  box-shadow:0 0 10px rgba(0,0,0,.1);
  padding-bottom: -90px !important;
}
#messages {
  padding:15px;
  height:400px;
  overflow-y:auto;
}
#input {
  display:flex;
  border-top:1px solid #ddd;
}
#input input {
  flex:1;
  padding:10px;
  border:none;
}
#input button {
  padding:10px 20px;
  background:#64b09d;
  color:white;
  border:none;
  cursor:pointer;
}