#chat-wrap { display:flex; flex-direction:column; height:100%; background:#0d1525; }
            #chat-topbar {
              display:flex; align-items:center; justify-content:space-between;
              padding:14px 20px 12px;
              background:rgba(255,255,255,0.03);
              border-bottom:1px solid rgba(255,255,255,0.07);
              flex-shrink:0;
            }
            #chat-topbar .ct-left { display:flex; align-items:center; gap:10px; }
            #chat-topbar .ct-dot {
              width:8px;height:8px;border-radius:50%;
              background:#34d399;box-shadow:0 0 8px rgba(52,211,153,.7);
              flex-shrink:0;
            }
            #chat-topbar .ct-title {
              font-size:.72rem;font-weight:800;color:#f1f5f9;letter-spacing:.01em;
            }
            #chat-topbar .ct-sub {
              font-size:.58rem;color:rgba(226,232,240,.38);font-weight:500;margin-top:1px;
            }
            #chat-topbar .ct-filter {
              display:flex;gap:3px;background:rgba(255,255,255,.04);
              border:1px solid rgba(255,255,255,.08);border-radius:7px;padding:3px;
            }
            #chat-topbar .ct-f-btn {
              padding:3px 9px;border-radius:5px;font-size:.57rem;font-weight:800;
              letter-spacing:.05em;text-transform:uppercase;cursor:pointer;
              border:none;background:none;color:rgba(226,232,240,.35);
              transition:all .15s;
            }
            #chat-topbar .ct-f-btn.ct-active { background:#38bdf8;color:#0f172a; }
            #chat-feed {
              flex:1;overflow-y:auto;padding:16px 20px;
              display:flex;flex-direction:column;gap:10px;
              scrollbar-width:thin;scrollbar-color:rgba(255,255,255,.08) transparent;
            }
            #chat-feed::-webkit-scrollbar{width:4px}
            #chat-feed::-webkit-scrollbar-thumb{background:rgba(255,255,255,.10);border-radius:99px}
            .chat-msg {
              display:flex;flex-direction:column;gap:4px;
              animation:msgIn .22s cubic-bezier(.4,0,.2,1) both;
            }
            @keyframes msgIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}
            .chat-msg-meta {
              display:flex;align-items:center;gap:8px;
            }
            .chat-msg-avatar {
              width:26px;height:26px;border-radius:8px;flex-shrink:0;
              background:linear-gradient(135deg,rgba(56,189,248,.3),rgba(136,108,192,.3));
              border:1px solid rgba(56,189,248,.25);
              display:flex;align-items:center;justify-content:center;
              font-size:.6rem;font-weight:900;color:#f1f5f9;
            }
            .chat-msg-name { font-size:.65rem;font-weight:800;color:#f1f5f9; }
            .chat-msg-tag {
              font-size:.54rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;
              padding:2px 7px;border-radius:99px;
              background:rgba(56,189,248,.12);color:#38bdf8;
              border:1px solid rgba(56,189,248,.18);
            }
            .chat-msg-time { font-size:.55rem;color:rgba(226,232,240,.28);margin-left:auto; }
            .chat-msg-bubble {
              background:rgba(255,255,255,.05);
              border:1px solid rgba(255,255,255,.07);
              border-radius:0 10px 10px 10px;
              padding:9px 13px;
              font-size:.82rem;line-height:1.65;color:#e2e8f0;
              margin-left:34px;
              word-break:break-word;
            }
            .chat-msg.chat-self .chat-msg-bubble {
              background:rgba(56,189,248,.12);
              border-color:rgba(56,189,248,.22);
              border-radius:10px 0 10px 10px;
              margin-left:auto;margin-right:0;
              max-width:85%;
            }
            .chat-msg.chat-self .chat-msg-meta { flex-direction:row-reverse; }
            .chat-msg.chat-self .chat-msg-avatar {
              background:linear-gradient(135deg,#38bdf8,#886CC0);
              border-color:rgba(56,189,248,.4);
            }
            .chat-msg.chat-self .chat-msg-time { margin-left:0;margin-right:auto; }
            .chat-empty {
              flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;
              gap:10px;color:rgba(226,232,240,.25);
            }
            .chat-empty-icon {
              width:48px;height:48px;border-radius:14px;
              background:rgba(56,189,248,.07);border:1px solid rgba(56,189,248,.12);
              display:flex;align-items:center;justify-content:center;
              font-size:1.3rem;
            }
            .chat-empty p { font-size:.72rem;font-weight:600;text-align:center;margin:0;line-height:1.6; }
            #chat-compose {
              flex-shrink:0;
              padding:12px 16px 16px;
              border-top:1px solid rgba(255,255,255,.07);
              background:rgba(8,14,26,.8);
            }
            #chat-compose-inner {
              background:rgba(255,255,255,.05);
              border:1px solid rgba(255,255,255,.10);
              border-radius:14px;
              overflow:hidden;
              transition:border-color .18s;
            }
            #chat-compose-inner:focus-within {
              border-color:rgba(56,189,248,.40);
              box-shadow:0 0 0 3px rgba(56,189,248,.08);
            }
            #chat-textarea {
              width:100%;min-height:72px;max-height:140px;
              background:transparent;border:none;outline:none;resize:none;
              color:#f1f5f9;font-family:'Inter',sans-serif;font-size:.84rem;
              line-height:1.6;padding:12px 14px 6px;
              scrollbar-width:thin;
            }
            #chat-textarea::placeholder { color:rgba(226,232,240,.25); }
            #chat-compose-footer {
              display:flex;align-items:center;justify-content:space-between;
              padding:6px 10px 8px;
            }
            .chat-lesson-pill {
              font-size:.56rem;font-weight:800;letter-spacing:.07em;text-transform:uppercase;
              padding:3px 9px;border-radius:99px;
              background:rgba(136,108,192,.15);color:#886CC0;
              border:1px solid rgba(136,108,192,.25);
            }
            #chat-send {
              width:32px;height:32px;border-radius:10px;
              background:#38bdf8;color:#0f172a;border:none;
              display:flex;align-items:center;justify-content:center;
              font-size:.8rem;cursor:pointer;flex-shrink:0;
              box-shadow:0 3px 10px rgba(56,189,248,.30);
              transition:filter .15s,transform .12s;
            }
            #chat-send:hover{filter:brightness(1.12)}
            #chat-send:active{transform:scale(.93)}