body{color:#000;background-color:#fff;max-width:600px;margin:auto;padding:40px 20px;font-family:Helvetica Neue,Arial,sans-serif}h2{border-bottom:2px solid #000;padding-bottom:10px}input{color:#000;box-sizing:border-box;background:#fff;border:1px solid #000;outline:none;width:100%;margin-bottom:10px;padding:10px;display:block}button{color:#fff;cursor:pointer;background:#000;border:none;width:100%;padding:10px 20px;font-weight:700}button:hover{background:#333}#chat{background:#f9f9f9;border:1px solid #000;height:400px;margin-bottom:20px;padding:15px;overflow-y:auto}.message-row{border-bottom:1px solid #eee;margin-bottom:10px;padding-bottom:5px;line-height:1.4}.username{margin-right:8px;font-weight:700}.error-text{color:#ff3b3b;margin-top:5px;font-size:.85rem;font-weight:300;display:block}.input-group{gap:10px;display:flex}.input-group input{margin-bottom:0}.input-group button{width:auto}