:root{font-family:Inter,system-ui,Segoe UI,Roboto,Arial; color:#222}
body{margin:0;background:#f4f6f8}
.center{display:flex;align-items:center;justify-content:center;height:100vh}
.card{width:360px;background:white;padding:22px;border-radius:10px;box-shadow:0 6px 18px rgba(20,30,50,0.08);text-align:center}
.card h1{margin:0 0 10px;font-size:20px}
.card input{width:100%;padding:10px;margin:8px 0;border:1px solid #e3e8ee;border-radius:6px}
.card button{width:100%;padding:10px;margin-top:8px;border:0;border-radius:6px;background:#2b6cb0;color:white;font-weight:600}
.card .error{color:#c53030;margin-top:8px}
.muted{color:#6b7280;font-size:13px}
.chat-wrap{display:flex;height:100vh}
.sidebar{width:220px;background:#ffffff;border-right:1px solid #e6eef9;padding:16px;box-shadow:2px 0 0 rgba(0,0,0,0.02)}
.sidebar h3{margin:0 0 8px}
.sidebar ul{list-style:none;padding:0;margin:0}
.sidebar li{padding:8px 6px;border-radius:6px;background:#f7fbff;margin-bottom:6px}
.main{flex:1;display:flex;flex-direction:column}
header{padding:16px;border-bottom:1px solid #eef4fb;background:white}
.messages{flex:1;padding:18px;overflow-y:auto;background:linear-gradient(180deg,#f8fbff, #fff)}
.message{margin-bottom:12px}
.message .meta{font-size:13px;color:#4a5568}
.message .text{margin-top:4px;font-size:15px}
.msgForm{display:flex;padding:12px;border-top:1px solid #eef4fb;background:white}
.msgForm input{flex:1;padding:10px;border:1px solid #e6eef9;border-radius:8px;margin-right:8px}
.msgForm button{padding:10px 14px;border-radius:8px;border:0;background:#2b6cb0;color:white}
.time{color:#94a3b8;font-size:12px;margin-left:8px}