:root{--bg: #f5f6f8;--panel: #ffffff;--border: #e6e8ec;--text: #1f2329;--muted: #8a919c;--primary: #2f6bff;--primary-hover: #1f57e0;--bubble-own: #2f6bff;--bubble-other: #f0f1f4;--radius: 12px}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased}button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}input,textarea{font-family:inherit}.auth-wrap{height:100%;display:flex;align-items:center;justify-content:center;padding:16px}.auth-card{width:100%;max-width:360px;background:var(--panel);border:1px solid var(--border);border-radius:16px;padding:28px 24px;display:flex;flex-direction:column;gap:14px;box-shadow:0 8px 30px #0000000f}.auth-title{margin:0;font-size:28px;text-align:center}.auth-sub{margin:-8px 0 4px;text-align:center;color:var(--muted);font-size:14px}.auth-tabs{display:flex;gap:8px;background:var(--bg);border-radius:10px;padding:4px}.auth-tabs .tab{flex:1;padding:8px;border-radius:8px;color:var(--muted);font-size:14px}.auth-tabs .tab.active{background:var(--panel);color:var(--text);font-weight:600;box-shadow:0 1px 3px #00000014}.field{display:flex;flex-direction:column;gap:6px;font-size:13px;color:var(--muted)}.field input{padding:10px 12px;border:1px solid var(--border);border-radius:10px;font-size:15px;outline:none}.field input:focus{border-color:var(--primary)}.primary{background:var(--primary);color:#fff;padding:11px;border-radius:10px;font-size:15px;font-weight:600}.primary:hover{background:var(--primary-hover)}.primary:disabled{opacity:.6;cursor:not-allowed}.error{color:#d64545;font-size:13px;text-align:center}.chat{height:100%;display:flex}.sidebar{width:300px;background:var(--panel);border-right:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0}.sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:14px 16px;border-bottom:1px solid var(--border)}.me{display:flex;align-items:center;gap:8px}.avatar{width:32px;height:32px;border-radius:50%;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:600}.name{font-weight:600}.logout{color:var(--muted);font-size:13px;padding:6px 8px;border-radius:8px}.logout:hover{background:var(--bg)}.search{padding:12px 16px;position:relative}.search input{width:100%;padding:9px 12px;border:1px solid var(--border);border-radius:10px;font-size:14px;outline:none}.search input:focus{border-color:var(--primary)}.search-results{position:absolute;left:16px;right:16px;top:50px;background:var(--panel);border:1px solid var(--border);border-radius:10px;box-shadow:0 6px 20px #0000001a;z-index:10;overflow:hidden}.search-results .result{display:block;width:100%;text-align:left;padding:10px 12px;font-size:14px}.search-results .result:hover{background:var(--bg)}.conv-list{flex:1;overflow-y:auto}.conv{display:flex;flex-direction:column;gap:3px;width:100%;text-align:left;padding:12px 16px;border-bottom:1px solid var(--bg)}.conv.active{background:#eef3ff}.conv-name{font-weight:600;font-size:15px}.conv-last{color:var(--muted);font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.empty{padding:24px 16px;color:var(--muted);font-size:14px;text-align:center}.chat-main{flex:1;display:flex;flex-direction:column;min-width:0}.chat-header{display:flex;align-items:center;gap:8px;padding:14px 16px;border-bottom:1px solid var(--border);background:var(--panel);font-weight:600}.back{display:none;font-size:22px;line-height:1;padding:0 4px;color:var(--muted)}.banner{background:#ffe9e9;color:#b53434;padding:8px 16px;font-size:13px;cursor:pointer}.messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:8px}.msg{display:flex}.msg.own{justify-content:flex-end}.bubble{max-width:70%;padding:9px 12px;border-radius:14px;font-size:15px;line-height:1.5;word-break:break-word}.msg:not(.own) .bubble{background:var(--bubble-other);border-bottom-left-radius:4px}.msg.own .bubble{background:var(--bubble-own);color:#fff;border-bottom-right-radius:4px}.file-chip{display:flex;flex-direction:column;gap:2px;align-items:flex-start;text-align:left}.msg:not(.own) .file-chip{color:var(--text)}.msg.own .file-chip{color:#fff}.file-name{font-weight:600;word-break:break-all}.file-meta{font-size:12px;opacity:.7}.file-action{font-size:12px;margin-top:4px;text-decoration:underline}.upload-progress{padding:10px 16px;border-top:1px solid var(--border);background:var(--panel)}.upload-progress-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px;font-size:13px}.upload-name{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;padding-right:12px}.upload-pct{color:var(--muted);flex-shrink:0}.upload-bar{height:4px;border-radius:2px;background:var(--bg);overflow:hidden}.upload-bar-fill{height:100%;background:var(--primary);transition:width .2s ease}.upload-progress--done .upload-bar-fill{background:#2fbf6e}.upload-progress--done .upload-pct{color:#2fbf6e}.input-bar{display:flex;align-items:flex-end;gap:8px;padding:12px 16px;border-top:1px solid var(--border);background:var(--panel)}.input-bar textarea{flex:1;resize:none;border:1px solid var(--border);border-radius:10px;padding:10px 12px;font-size:15px;max-height:120px;outline:none}.input-bar textarea:focus{border-color:var(--primary)}.attach{width:40px;height:40px;border-radius:10px;background:var(--bg);font-size:22px;line-height:1;color:var(--muted);flex-shrink:0}.send{background:var(--primary);color:#fff;padding:10px 16px;border-radius:10px;font-weight:600;flex-shrink:0}.send:disabled{opacity:.5;cursor:not-allowed}.chat-empty{flex:1;display:flex;align-items:center;justify-content:center;color:var(--muted)}@media (max-width: 768px){.sidebar{width:100%;border-right:none}.chat-main,.chat--active .sidebar{display:none}.chat--active .chat-main{display:flex}.back{display:inline-block}.bubble{max-width:85%}}