body {
  margin:0;
  font-family: sans-serif;
  background:#111;
  color:#fff;
}
header {
  padding:10px;
  font-size:20px;
  background:#222;
  text-align:center;
}
#chat {
  height:calc(100vh - 140px);
  overflow-y:auto;
  padding:15px;
}
.msg {
  padding:10px 15px;
  margin:10px 0;
  border-radius:10px;
  max-width:80%;
  line-height:1.4;
}
.msg.ai {
  background:#333;
  color:#eee;
}
.msg.me {
  background:#005eff;
  color:#fff;
  margin-left:auto;
  text-align:right;
}
footer {
  position:fixed;
  bottom:0;
  left:0;
  right:0;
  background:#222;
  padding:10px;
  display:flex;
  gap:8px;
}
footer input {
  flex:1;
  padding:12px;
  border-radius:8px;
  border:none;
  font-size:16px;
}
footer button {
  padding:12px 16px;
  border:none;
  background:#005eff;
  color:#fff;
  border-radius:8px;
  font-size:16px;
}