:root{--bg:#e9edf0;--sidebar-bg:#fff;--panel:#f7f9fa;--ink:#1c2b33;--ink-soft:#64757e;--accent:#3d8a6f;--accent-ink:#fff;--bubble-mine:#a8e6a1;--bubble-mine-ink:#10231a;--bubble-theirs:#fff;--bubble-theirs-ink:#1c2b33;--line:#dde4e8;--danger:#c0392b;--radius:18px;font-family:system-ui,-apple-system,Segoe UI,Noto Sans TC,PingFang TC,Microsoft JhengHei,sans-serif}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased}input,button{font-family:inherit;font-size:15px}@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}.center-screen{place-items:center;min-height:100%;padding:24px;display:grid}.card{background:#fff;border-radius:24px;width:100%;max-width:380px;padding:36px 30px;box-shadow:0 12px 40px #1c2b331a}.card .logo{letter-spacing:4px;margin:0;font-size:34px;font-weight:700}.card h1{margin:0 0 4px;font-size:24px}.card pre{background:var(--panel);border:1px solid var(--line);white-space:pre-wrap;border-radius:12px;padding:14px;font-size:13px;overflow-x:auto}.muted{color:var(--ink-soft);margin:4px 0 20px;font-size:14px}.hint{color:var(--ink-soft);margin-top:14px;font-size:12.5px;line-height:1.5}.splash{color:var(--ink-soft);font-size:15px}.auth .tabs{gap:8px;margin:18px 0;display:flex}.auth .tabs button{border:1px solid var(--line);color:var(--ink-soft);cursor:pointer;background:#fff;border-radius:12px;flex:1;padding:10px;transition:all .15s}.auth .tabs button.on{background:var(--accent);color:#fff;border-color:var(--accent)}.card input{border:1px solid var(--line);background:var(--panel);border-radius:12px;outline:none;width:100%;margin-bottom:12px;padding:13px 14px;transition:all .15s}.card input:focus{border-color:var(--accent);background:#fff}button.primary{background:var(--accent);color:#fff;cursor:pointer;border:none;border-radius:12px;width:100%;padding:13px;font-weight:600;transition:all .15s}button.primary:hover{filter:brightness(1.05)}button.primary:disabled{opacity:.55;cursor:default}.error{color:var(--danger);background:#fdecea;border-radius:10px;margin-bottom:12px;padding:10px 12px;font-size:13.5px}.app{grid-template-columns:300px 1fr;height:100%;display:grid}.sidebar{background:var(--sidebar-bg);border-right:1px solid var(--line);flex-direction:column;display:flex}.side-head{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;padding:18px 20px;display:flex}.brand{letter-spacing:3px;font-size:20px;font-weight:700}button.ghost{color:var(--ink-soft);cursor:pointer;background:0 0;border:none;font-size:14px}button.ghost:hover{color:var(--ink)}.new-chat{border:1px dashed var(--line);background:var(--panel);color:var(--accent);cursor:pointer;border-radius:12px;margin:14px 16px;padding:11px;font-weight:600;transition:all .15s}.new-chat:hover{border-color:var(--accent)}.room-list{flex:1;margin:0;padding:4px 10px;list-style:none;overflow-y:auto}.room-list li{cursor:pointer;border-radius:14px;align-items:center;gap:12px;padding:11px 12px;transition:all .12s;display:flex}.room-list li:hover{background:var(--panel)}.room-list li.on{background:#e6f2ec}.room-list li.empty{color:var(--ink-soft);cursor:default;justify-content:center;padding:30px 12px;font-size:13.5px}.room-list li.empty:hover{background:0 0}.avatar{background:var(--accent);color:#fff;border-radius:50%;flex-shrink:0;place-items:center;width:40px;height:40px;font-weight:600;display:grid}.room-name{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.main{flex-direction:column;min-width:0;display:flex}.placeholder{color:var(--ink-soft);flex:1;place-items:center;display:grid}.room{flex-direction:column;height:100%;display:flex}.room-head{border-bottom:1px solid var(--line);background:var(--sidebar-bg);padding:16px 22px;font-weight:600}.messages{flex-direction:column;flex:1;gap:10px;padding:22px;display:flex;overflow-y:auto}.empty-msg{color:var(--ink-soft);margin:auto;font-size:14px}.bubble-row{display:flex}.bubble-row.mine{justify-content:flex-end}.bubble-row.theirs{justify-content:flex-start}.bubble{border-radius:var(--radius);word-break:break-word;max-width:62%;padding:10px 14px;line-height:1.45;box-shadow:0 1px 2px #1c2b330f}.mine .bubble{background:var(--bubble-mine);color:var(--bubble-mine-ink);border-bottom-right-radius:6px}.theirs .bubble{background:var(--bubble-theirs);color:var(--bubble-theirs-ink);border-bottom-left-radius:6px}.composer{border-top:1px solid var(--line);background:var(--sidebar-bg);gap:10px;padding:14px 18px;display:flex}.composer input{border:1px solid var(--line);background:var(--panel);border-radius:22px;outline:none;flex:1;padding:12px 16px;transition:all .15s}.composer input:focus{border-color:var(--accent);background:#fff}.send{background:var(--accent);color:#fff;cursor:pointer;border:none;border-radius:22px;padding:0 20px;font-weight:600;transition:all .15s}.send:disabled{opacity:.5;cursor:default}.modal-backdrop{z-index:10;background:#1c2b3366;place-items:center;padding:24px;display:grid;position:fixed;inset:0}.modal{background:#fff;border-radius:20px;width:100%;max-width:340px;padding:26px}.modal h2{margin:0 0 4px;font-size:19px}.modal input{border:1px solid var(--line);background:var(--panel);border-radius:12px;outline:none;width:100%;margin-bottom:12px;padding:12px 14px}.modal input:focus{border-color:var(--accent);background:#fff}.modal-actions{justify-content:flex-end;gap:10px;display:flex}.modal-actions .ghost{padding:10px 16px}.modal-actions .primary{width:auto;padding:10px 20px}@media (width<=640px){.app{grid-template-columns:1fr}.sidebar{display:none}}