:root{--bg-primary:#ffffff;--bg-secondary:#f8f9fa;--bg-tertiary:#f0f1f3;--bg-hover:#e8eaed;--text-primary:#1a1a2e;--text-secondary:#5f6368;--text-tertiary:#9aa0a6;--border-color:#e0e0e0;--border-light:#f0f0f0;--accent:#4f46e5;--accent-hover:#4338ca;--accent-light:#eef2ff;--success:#10b981;--warning:#f59e0b;--danger:#ef4444;--radius:12px;--radius-sm:8px;--radius-xs:6px;--shadow:0 1px 3px rgba(0,0,0,0.06);--shadow-md:0 4px 12px rgba(0,0,0,0.08);}*{margin:0;padding:0;box-sizing:border-box;}body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;color:var(--text-primary);background:var(--bg-secondary);line-height:1.6;height:100vh;overflow:hidden;}.app-container{display:flex;height:100vh;}.sidebar{width:280px;min-width:280px;background:var(--bg-primary);border-right:1px solid var(--border-color);display:flex;flex-direction:column;transition:margin-left .3s,opacity .3s;overflow-y:auto;}.sidebar.collapsed{margin-left:-280px;opacity:0;pointer-events:none;}.sidebar-header{padding:20px 20px 16px;border-bottom:1px solid var(--border-light);}.logo{font-size:18px;font-weight:600;color:var(--accent);margin-bottom:4px;}.subtitle{font-size:12px;color:var(--text-tertiary);}.sidebar-section{padding:16px 20px;border-bottom:1px solid var(--border-light);}.section-title{font-size:12px;font-weight:600;color:var(--text-tertiary);text-transform:uppercase;letter-spacing:.5px;margin-bottom:12px;}.upload-area{margin-bottom:12px;}.upload-hint{font-size:11px;color:var(--text-tertiary);margin-top:6px;text-align:center;}.doc-list{max-height:200px;overflow-y:auto;margin-bottom:8px;}.empty-hint{font-size:13px;color:var(--text-tertiary);text-align:center;padding:12px 0;}.doc-item{display:flex;align-items:center;justify-content:space-between;padding:8px 10px;border-radius:var(--radius-xs);cursor:pointer;transition:background .15s;}.doc-item:hover{background:var(--bg-tertiary);}.doc-item-name{font-size:13px;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;margin-right:8px;}.doc-item-count{font-size:11px;color:var(--text-tertiary);margin-right:8px;white-space:nowrap;}.doc-item-delete{color:var(--text-tertiary);cursor:pointer;padding:2px 6px;border-radius:4px;font-size:12px;border:none;background:none;transition:color .15s;}.doc-item-delete:hover{color:var(--danger);background:#fef2f2;}.doc-count{font-size:12px;color:var(--text-tertiary);}.setting-row{display:flex;align-items:center;gap:8px;margin-bottom:10px;font-size:13px;}.setting-row input[type="range"]{flex:1;height:4px;}.range-value{font-size:12px;color:var(--text-tertiary);min-width:28px;text-align:right;}.sidebar-footer{margin-top:auto;padding:12px 20px;border-top:1px solid var(--border-light);display:flex;align-items:center;gap:8px;font-size:12px;color:var(--text-tertiary);}.status-dot{width:8px;height:8px;border-radius:50%;background:var(--success);}.status-dot.error{background:var(--danger);}.status-dot.loading{background:var(--warning);animation:pulse 1s infinite;}@keyframes pulse{0%,100%{opacity:1;}50%{opacity:.4;}}.main{flex:1;display:flex;flex-direction:column;min-width:0;background:var(--bg-secondary);}.chat-header{display:flex;align-items:center;gap:12px;padding:12px 20px;background:var(--bg-primary);border-bottom:1px solid var(--border-color);}.model-badge{font-size:12px;background:var(--accent-light);color:var(--accent);padding:4px 10px;border-radius:12px;font-weight:500;}.rag-badge{font-size:11px;background:#ecfdf5;color:var(--success);padding:4px 10px;border-radius:12px;font-weight:500;}.rag-badge.disabled{background:var(--bg-tertiary);color:var(--text-tertiary);}.btn{padding:8px 16px;border-radius:var(--radius-xs);border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font-size:13px;cursor:pointer;transition:all .15s;}.btn:hover{background:var(--bg-hover);}.btn-primary{background:var(--accent);color:#fff;border-color:var(--accent);}.btn-primary:hover{background:var(--accent-hover);}.btn-full{width:100%;text-align:center;}.btn-sm{padding:5px 12px;font-size:12px;border-radius:var(--radius-xs);border:1px solid var(--border-color);background:var(--bg-primary);cursor:pointer;}.btn-sm:hover{background:var(--bg-hover);}.btn-icon{padding:6px 10px;font-size:16px;border:none;background:none;cursor:pointer;color:var(--text-secondary);}.btn-icon:hover{color:var(--text-primary);}.btn-close{border:none;background:none;font-size:18px;cursor:pointer;color:var(--text-tertiary);padding:0 4px;}.btn-close:hover{color:var(--text-primary);}.chat-messages{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:16px;}.welcome-message{text-align:center;padding:60px 20px;max-width:500px;margin:auto;}.welcome-icon{font-size:48px;margin-bottom:16px;}.welcome-message h2{font-size:20px;font-weight:600;margin-bottom:8px;}.welcome-message p{color:var(--text-secondary);margin-bottom:24px;}.quick-prompts{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;}.quick-prompt{padding:8px 16px;border-radius:20px;border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font-size:13px;cursor:pointer;transition:all .15s;}.quick-prompt:hover{border-color:var(--accent);color:var(--accent);background:var(--accent-light);}.message{display:flex;gap:12px;max-width:85%;}.message.user{align-self:flex-end;flex-direction:row-reverse;}.message.assistant{align-self:flex-start;}.message-avatar{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:16px;flex-shrink:0;}.message.user .message-avatar{background:var(--accent);color:#fff;}.message.assistant .message-avatar{background:var(--bg-tertiary);color:var(--text-secondary);}.message-content{padding:12px 16px;border-radius:var(--radius);line-height:1.7;word-break:break-word;}.message.user .message-content{background:var(--accent);color:#fff;border-bottom-right-radius:4px;}.message.assistant .message-content{background:var(--bg-primary);color:var(--text-primary);border:1px solid var(--border-color);border-bottom-left-radius:4px;}.message-content p{margin-bottom:8px;}.message-content p:last-child{margin-bottom:0;}.message-content ul,.message-content ol{margin:8px 0;padding-left:20px;}.message-content code{background:rgba(0,0,0,0.06);padding:2px 6px;border-radius:4px;font-size:13px;}.message-content pre{background:#1a1a2e;color:#e0e0e0;padding:12px 16px;border-radius:var(--radius-sm);overflow-x:auto;margin:8px 0;}.message-content pre code{background:none;padding:0;color:inherit;}.message-meta{font-size:11px;color:var(--text-tertiary);margin-top:4px;}.message.user .message-meta{text-align:right;}.typing-dot{display:inline-block;width:6px;height:6px;background:var(--text-tertiary);border-radius:50%;animation:bounce 1.4s infinite;margin:0 2px;}.typing-dot:nth-child(2){animation-delay:.2s;}.typing-dot:nth-child(3){animation-delay:.4s;}@keyframes bounce{0%,60%,100%{transform:translateY(0);}30%{transform:translateY(-4px);}}.chat-input-area{padding:16px 20px;background:var(--bg-primary);border-top:1px solid var(--border-color);display:flex;align-items:flex-end;gap:12px;}.chat-input-area textarea{flex:1;padding:10px 14px;border:1px solid var(--border-color);border-radius:var(--radius-sm);font-size:14px;font-family:inherit;resize:none;max-height:120px;min-height:42px;outline:none;transition:border-color .15s;line-height:1.5;}.chat-input-area textarea:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-light);}.chat-input-area .btn-primary{height:42px;min-width:72px;font-size:14px;}.chat-input-area .btn-primary:disabled{opacity:.5;cursor:not-allowed;}.context-preview{padding:12px 20px;background:#fffbeb;border-top:1px solid #fde68a;}.context-header{display:flex;justify-content:space-between;align-items:center;font-size:12px;color:var(--warning);font-weight:600;margin-bottom:8px;}.context-chunks{display:flex;gap:8px;overflow-x:auto;padding-bottom:4px;}.context-chunk{min-width:200px;max-width:300px;padding:8px 12px;background:#fff;border:1px solid #fde68a;border-radius:var(--radius-xs);font-size:12px;color:var(--text-secondary);line-height:1.5;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}.modal{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.3);display:flex;align-items:center;justify-content:center;z-index:100;}.modal-content{background:var(--bg-primary);padding:32px;border-radius:var(--radius);min-width:300px;text-align:center;}.modal-content h3{font-size:16px;margin-bottom:16px;}.progress-bar{height:6px;background:var(--bg-tertiary);border-radius:3px;overflow:hidden;margin-bottom:12px;}.progress-fill{height:100%;background:var(--accent);border-radius:3px;width:0%;transition:width .3s;}::-webkit-scrollbar{width:6px;height:6px;}::-webkit-scrollbar-track{background:transparent;}::-webkit-scrollbar-thumb{background:#d0d0d0;border-radius:3px;}::-webkit-scrollbar-thumb:hover{background:#b0b0b0;}.user-bar{display:flex;align-items:center;justify-content:space-between;margin-top:12px;padding-top:12px;border-top:1px solid var(--border-light);}.user-name{font-size:13px;color:var(--text-secondary);font-weight:500;}.btn-outline{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-secondary);padding:4px 12px;border-radius:var(--radius-xs);font-size:12px;cursor:pointer;transition:all .15s;}.btn-outline:hover{border-color:var(--danger);color:var(--danger);background:#fef2f2;}@media(max-width:768px){.sidebar{position:fixed;left:0;top:0;height:100%;z-index:50;box-shadow:var(--shadow-md);}.message{max-width:95%;}}