#chat-box {
  width: 300px;
  background:#fff;
  border:1px solid #ccc;
  padding:10px;
  border-radius:10px;
  position:fixed;
  bottom:20px;
  right:20px;
}
.user-msg { text-align:right; color:blue; margin:5px 0; }
.agent-msg { text-align:left; color:green; margin:5px 0; }