body {
  font-family: Arial, sans-serif;
  background: #ece5dd;
  margin: 0;
  padding: 0;
}
.container { max-width: 900px; margin: 30px auto; padding: 20px; }
.chat-container { max-width: 400px; margin: 30px auto; background: #fff; border-radius: 10px; overflow: hidden; box-shadow: 0px 0px 8px rgba(0,0,0,0.2); }
.chat-header { background: #075E54; color: #fff; padding: 15px; text-align: center; }
#chat { height: 400px; overflow-y: auto; padding: 10px; background: #ece5dd; }
.message { margin: 8px 0; padding: 8px 12px; border-radius: 15px; display: inline-block; max-width: 70%; }
.sent { background: #dcf8c6; float: right; clear: both; }
.received { background: #fff; float: left; clear: both; }
.chat-input { display: flex; border-top: 1px solid #ddd; }
.chat-input input { flex: 1; border: none; padding: 12px; font-size: 14px; }
.chat-input button { background: #075E54; border: none; color: #fff; padding: 12px 20px; cursor: pointer; }
.nav { margin-bottom: 20px; }
.table { width: 100%; border-collapse: collapse; }
.table th, .table td { padding: 8px; border: 1px solid #ddd; }