:root{
  --bg:#f2f4f7; --card:#fff; --line:#e5e8ec; --txt:#1f2329; --sub:#8b929c;
  --pri:#3b6ef5; --pri-d:#2a58d0; --ok:#16a34a; --err:#dc2626;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;background:var(--bg);color:var(--txt);
  font:14px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  -webkit-font-smoothing:antialiased;
}
.hidden{display:none!important}
button{font:inherit;cursor:pointer;border:0;border-radius:8px}
input,textarea{font:inherit;color:inherit}

/* ---------- 登录 / 注册 ---------- */
.auth-wrap{min-height:100%;display:flex;align-items:center;justify-content:center;padding:20px}
.auth-card{width:100%;max-width:360px;background:var(--card);border:1px solid var(--line);
  border-radius:14px;padding:28px 24px;box-shadow:0 8px 30px rgba(16,24,40,.06)}
.auth-title{margin:0 0 6px;font-size:20px}
.auth-sub{margin:0 0 18px;color:var(--sub);font-size:13px}
.tabs{display:flex;gap:8px;margin-bottom:16px;background:#f0f2f5;padding:4px;border-radius:10px}
.tab{flex:1;padding:8px;background:transparent;color:var(--sub);border-radius:8px}
.tab.active{background:#fff;color:var(--txt);box-shadow:0 1px 3px rgba(16,24,40,.08)}
#authForm{display:flex;flex-direction:column;gap:12px}
#authForm input{padding:11px 13px;border:1px solid var(--line);border-radius:9px;background:#fafbfc;outline:none}
#authForm input:focus{border-color:var(--pri);background:#fff}
.btn-primary{background:var(--pri);color:#fff;padding:11px 16px;font-weight:500}
.btn-primary:hover{background:var(--pri-d)}
.btn-primary:disabled{opacity:.6;cursor:not-allowed}
.btn-ghost{background:transparent;color:var(--sub);padding:6px 10px;font-size:13px}
.btn-ghost:hover{background:#eef0f3;color:var(--txt)}
.btn-sm{padding:7px 12px;font-size:13px}
.msg{margin-top:12px;font-size:13px;min-height:18px}
.msg.err{color:var(--err)}
.msg.ok{color:var(--ok)}

/* ---------- 主视图 ---------- */
#appView{height:100%;display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:10px 16px;background:#fff;border-bottom:1px solid var(--line);flex-shrink:0}
.topbar-left,.topbar-right{display:flex;align-items:center;gap:10px;min-width:0}
.brand{font-weight:600;white-space:nowrap}
.conn{font-size:12px;padding:2px 8px;border-radius:20px;white-space:nowrap}
.conn.online{background:#e7f7ee;color:var(--ok)}
.conn.offline{background:#f0f2f5;color:var(--sub)}
.conn.error{background:#fdeaea;color:var(--err)}
.who{color:var(--sub);font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

/* ---------- 消息区 ---------- */
.chat{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:10px}
.bubble{max-width:min(78%,620px);padding:9px 13px;border-radius:12px;background:#fff;
  border:1px solid var(--line);align-self:flex-start}
.bubble.out{align-self:flex-end;background:var(--pri);border-color:var(--pri);color:#fff}
.bubble.sys{align-self:center;background:#fff7e6;border-color:#ffe0a3;color:#8a6100;font-size:13px;max-width:90%}
.bubble .meta{font-size:11px;opacity:.65;margin-bottom:3px}
.bubble .text{white-space:pre-wrap;word-break:break-word}
.empty{margin:auto;color:var(--sub);font-size:13px}

/* ---------- 输入区 ---------- */
.composer{display:flex;gap:10px;align-items:flex-end;padding:12px 16px;
  background:#fff;border-top:1px solid var(--line);flex-shrink:0}
.composer textarea{flex:1;resize:none;max-height:120px;padding:10px 12px;
  border:1px solid var(--line);border-radius:10px;background:#fafbfc;outline:none}
.composer textarea:focus{border-color:var(--pri);background:#fff}
.composer textarea:disabled{background:#f5f6f8;color:var(--sub)}

/* ---------- 管理员布局 ---------- */
.admin-layout{flex:1;display:flex;min-height:0}
.sidebar{width:250px;flex-shrink:0;background:#fff;border-right:1px solid var(--line);
  display:flex;flex-direction:column;min-height:0}
.sidebar-head{padding:12px;border-bottom:1px solid var(--line)}
.sidebar-head button{width:100%}
.user-list{list-style:none;margin:0;padding:6px;overflow-y:auto;flex:1}
.user-item{display:flex;align-items:center;gap:8px;padding:9px 10px;border-radius:9px;cursor:pointer}
.user-item:hover{background:#f5f7fa}
.user-item.active{background:#eaf0fe}
.dot{width:8px;height:8px;border-radius:50%;flex-shrink:0}
.dot.on{background:var(--ok)}
.dot.off{background:#c9ced6}
.uname{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ustate{font-size:11px;color:var(--sub);flex-shrink:0}
.admin-main{flex:1;display:flex;flex-direction:column;min-width:0}
.chat-head{padding:10px 16px;border-bottom:1px solid var(--line);background:#fff;
  font-size:13px;color:var(--sub);flex-shrink:0}
.chat-head b{color:var(--txt)}
.hint{padding:8px 12px;margin:0 16px 12px;background:#eef2ff;border-radius:8px;
  font-size:12px;color:#4557c4}

/* ---------- 弹层（QQ 绑定） ---------- */
.modal{position:fixed;inset:0;background:rgba(16,24,40,.45);display:flex;
  align-items:center;justify-content:center;padding:20px;z-index:50}
.modal-card{width:100%;max-width:400px;background:#fff;border-radius:14px;padding:18px 20px;
  box-shadow:0 12px 40px rgba(16,24,40,.2)}
.modal-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px}
.modal-body{font-size:13px}
.modal-body p{margin:0 0 10px}
.code-box{margin:4px 0 10px;padding:14px;background:#f2f5ff;border:1px dashed #b9c8f7;
  border-radius:10px;text-align:center;font-size:30px;font-weight:600;letter-spacing:6px;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
.tip{color:var(--sub);font-size:12px;margin:8px 0 0}
.row{display:flex;gap:8px;align-items:center;margin-top:12px}

/* ---------- 标签 ---------- */
.badge{display:inline-block;margin-left:5px;padding:0 5px;border-radius:4px;
  background:#e8f0fe;color:#3b6ef5;font-size:10px;vertical-align:1px}
.bubble.out .badge{background:rgba(255,255,255,.28);color:#fff}
.chip{flex-shrink:0;padding:0 5px;border-radius:4px;background:#e8f0fe;color:#3b6ef5;font-size:10px}

@media(max-width:640px){
  .admin-layout{flex-direction:column}
  .sidebar{width:100%;max-height:38vh;border-right:0;border-bottom:1px solid var(--line)}
  .bubble{max-width:88%}
}