.chat-box {
  height: 420px;
  overflow-y: auto;
  background: #fafafa;
  border: 1px solid #ddd;
  border-radius: 6px;
  padding: 12px;
}
.msg { margin-bottom: 10px; }
.msg.me { text-align: right; }
.bubble {
  display: inline-block;
  max-width: 70%;
  padding: 8px 12px;
  border-radius: 12px;
  background: #fff;
  border: 1px solid #ddd;
}
.msg.me .bubble { background: #e6f0ff; }
.meta { font-size: 11px; color: #777; margin-top: 3px; }