*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",sans-serif;background:#eef2f7;color:#1b2430;height:100vh}
[hidden]{display:none!important}
.btn{background:#0068ff;color:#fff;border:0;border-radius:8px;padding:10px 18px;font-size:15px;cursor:pointer}
.btn:hover{background:#0053cc}
.link{background:none;border:0;color:#0068ff;cursor:pointer;font-size:14px}
.error{color:#d92d20;min-height:1.2em}
.login{display:grid;place-items:center;height:100%}
.login-card{background:#fff;padding:32px;border-radius:16px;box-shadow:0 8px 30px #0001;text-align:center;max-width:380px;width:92%}
.login-card h1{margin:0 0 8px;color:#0068ff}
.qr-box img{width:240px;height:240px;margin:12px auto;display:block}
.app{display:flex;height:100%;background:#fff}
.sidebar{width:340px;border-right:1px solid #e3e8ef;display:flex;flex-direction:column}
.side-head{display:flex;justify-content:space-between;align-items:center;padding:14px 16px;font-weight:600}
.search{margin:0 12px 8px;padding:9px 12px;border:1px solid #d5dbe5;border-radius:8px}
.conv-list{list-style:none;margin:0;padding:0;overflow:auto;flex:1}
.conv{display:flex;gap:10px;align-items:center;padding:10px 16px;cursor:pointer}
.conv:hover,.conv.active{background:#e8f1ff}
.avatar{width:42px;height:42px;border-radius:50%;background:#0068ff;color:#fff;display:grid;place-items:center;object-fit:cover;flex:none;font-weight:600}
.conv .name{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.badge{margin-left:auto;background:#e53935;color:#fff;border-radius:10px;font-size:12px;padding:1px 7px}
.chat{flex:1;display:flex;flex-direction:column;min-width:0;background:#e9eef5}
.chat-head{padding:14px 16px;background:#fff;border-bottom:1px solid #e3e8ef;display:flex;gap:10px;align-items:center}
.back{display:none;font-size:20px}
.messages{flex:1;overflow:auto;padding:16px;display:flex;flex-direction:column;gap:6px}
.msg{max-width:70%;padding:8px 12px;border-radius:12px;background:#fff;align-self:flex-start;word-break:break-word;white-space:pre-wrap}
.msg.self{background:#cfe3ff;align-self:flex-end}
.msg small{display:block;color:#6b7686;font-size:11px;margin-top:2px}
.msg .who{font-weight:600;font-size:12px;color:#0068ff}
.composer{display:flex;gap:8px;padding:12px;background:#fff;border-top:1px solid #e3e8ef}
.composer input{flex:1;padding:10px 12px;border:1px solid #d5dbe5;border-radius:8px;font-size:15px}
@media(max-width:700px){
.sidebar{width:100%}.chat{display:none}
.app.in-chat .sidebar{display:none}.app.in-chat .chat{display:flex}
.back{display:block}
}