:root{--bg-primary: #0f1117;--bg-secondary: #1a1d27;--bg-card: #1e2130;--accent: #6366f1;--accent-hover: #4f46e5;--text-primary: #f1f5f9;--text-secondary: #94a3b8;--border: #2d3148;--success: #22c55e;--error: #ef4444;--warning: #f59e0b;font-family:Inter,system-ui,sans-serif;color:var(--text-primary);background:radial-gradient(circle at top,#182033 0%,var(--bg-primary) 45%)}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:var(--bg-primary);color:var(--text-primary)}a{color:#c7d2fe}button,input,textarea,select{font:inherit}button{transition:background .2s ease}button:hover{background:var(--accent-hover)}.auth-shell{min-height:100vh;display:grid;place-items:center;padding:24px}.auth-card{width:min(420px,100%);display:flex;flex-direction:column;gap:12px;background:var(--bg-card);border:1px solid var(--border);border-radius:18px;padding:28px}.auth-card input,.auth-card button,.chat-form textarea{border-radius:12px;border:1px solid var(--border);background:var(--bg-secondary);color:var(--text-primary);padding:12px 14px}.auth-card button,.chat-form button,.ghost-button{display:inline-flex;align-items:center;gap:8px;justify-content:center;border:none;background:var(--accent);color:#fff;cursor:pointer}.form-error{color:var(--error);font-size:14px}.page-shell{padding:24px}.topbar{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:24px}.topbar h1{margin:0 0 6px}.topbar p{margin:0;color:var(--text-secondary)}.topbar-actions{display:flex;gap:12px}.warning-banner{margin-bottom:20px;padding:14px 16px;border-radius:12px;background:#f59e0b22;border:1px solid var(--warning);color:#fcd34d}.documents-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px}.chat-layout{height:100vh;display:grid;grid-template-columns:220px 1fr 380px;overflow:hidden}.chat-sidebar{background:#12141f;border-right:1px solid var(--border);overflow-y:auto;display:flex;flex-direction:column;gap:2px;padding:12px 8px}.sidebar-back{display:flex;align-items:center;gap:6px;color:var(--text-secondary);text-decoration:none;font-size:12px;padding:6px 8px;border-radius:6px;margin-bottom:8px;transition:background .15s}.sidebar-back:hover{background:var(--bg-card);color:var(--text-primary)}.sidebar-section-header{display:flex;align-items:center;justify-content:space-between;padding:4px 8px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--text-secondary);margin-bottom:2px}.icon-btn{display:flex;align-items:center;justify-content:center;background:none;border:none;color:var(--text-secondary);cursor:pointer;padding:3px;border-radius:4px;transition:background .15s,color .15s}.icon-btn:hover{background:var(--bg-card);color:var(--text-primary)}.icon-btn.danger:hover{color:var(--error);background:#ef444422}.new-folder-row{display:flex;gap:4px;padding:4px 8px}.new-folder-row input{flex:1;font-size:12px;padding:4px 8px;border-radius:6px;border:1px solid var(--border);background:var(--bg-secondary);color:var(--text-primary)}.new-folder-row button{font-size:11px;padding:4px 8px;border-radius:6px;border:none;background:var(--accent);color:#fff;cursor:pointer}.folder-group{border-radius:8px;margin-bottom:2px;transition:background .15s}.folder-group.drag-over{background:var(--accent)22;outline:1px dashed var(--accent)}.folder-header{display:flex;align-items:center;gap:4px;padding:2px 4px}.folder-toggle{flex:1;display:flex;align-items:center;gap:5px;background:none;border:none;color:var(--text-secondary);font-size:12px;cursor:pointer;padding:4px;border-radius:6px;text-align:left;transition:background .15s,color .15s;min-width:0}.folder-toggle:hover{background:var(--bg-card);color:var(--text-primary)}.folder-toggle span:first-of-type{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.folder-count{font-size:10px;background:var(--bg-card);border-radius:10px;padding:1px 6px;color:var(--text-secondary);flex-shrink:0}.unfiled-label{flex:1;font-size:12px;color:var(--text-secondary);padding:4px 8px}.folder-docs{padding:2px 0 2px 12px;display:flex;flex-direction:column;gap:1px}.empty-folder{font-size:11px;color:var(--text-secondary);padding:4px 8px;font-style:italic;opacity:.7}.sidebar-doc-row{display:flex;align-items:center;gap:6px;padding:5px 8px;border-radius:6px;cursor:pointer;font-size:12px;color:var(--text-secondary);transition:background .15s,color .15s;min-width:0}.sidebar-doc-row:hover{background:var(--bg-card);color:var(--text-primary)}.sidebar-doc-row.selected{color:var(--text-primary)}.sidebar-doc-row input{flex-shrink:0;accent-color:var(--accent)}.doc-label{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1}.viewer-pane{background:#0d0f1a;border-right:1px solid var(--border);overflow:auto;display:flex;flex-direction:column;align-items:center;padding:16px;gap:12px}.pdf-stage{position:relative;display:inline-block;max-width:100%}.pdf-canvas{display:block;max-width:100%;height:auto;background:#fff;border-radius:10px;box-shadow:0 20px 50px #00000059}.pdf-overlay{position:absolute;top:0;left:0;pointer-events:none}.viewer-error{color:var(--error);background:#ef444422;border:1px solid var(--error);padding:12px 14px;border-radius:10px;width:100%}.viewer-info{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--text-secondary);align-self:flex-start;background:var(--bg-secondary);padding:5px 10px;border-radius:6px;border:1px solid var(--border);max-width:100%;overflow:hidden}.viewer-info strong{color:var(--text-primary);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.viewer-placeholder{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;gap:14px;color:var(--text-secondary);font-size:13px;opacity:.5}.chat-main{background:var(--bg-card);display:flex;flex-direction:column;overflow:hidden}.chat-header{padding:12px 16px;border-bottom:1px solid var(--border);font-weight:600;font-size:13px;display:flex;align-items:center;justify-content:space-between;flex-shrink:0}.chat-header-meta{font-size:11px;font-weight:400;color:var(--text-secondary)}.messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:10px}.messages-empty{color:var(--text-secondary);font-size:13px;text-align:center;margin-top:40px}.message{max-width:88%;padding:10px 13px;border-radius:14px;font-size:13px;line-height:1.65}.message.user{align-self:flex-end;background:var(--accent);color:#fff;border-bottom-right-radius:4px}.message.assistant{align-self:flex-start;background:var(--bg-secondary);border-bottom-left-radius:4px}.message.loading{opacity:.5}.markdown-content p,.markdown-content ol,.markdown-content h1,.markdown-content h2,.markdown-content h3{margin:0 0 10px}.markdown-content p:last-child,.markdown-content ol:last-child,.markdown-content h1:last-child,.markdown-content h2:last-child,.markdown-content h3:last-child{margin-bottom:0}.markdown-content ol{padding-left:18px}.markdown-content li+li{margin-top:6px}.markdown-content strong{color:#fff;font-weight:700}.markdown-content code{background:#ffffff14;border:1px solid rgba(255,255,255,.08);border-radius:6px;padding:1px 6px;font-size:.92em}.markdown-content a{color:#c4b5fd}.sources-toggle{display:inline-flex;align-items:center;gap:4px;background:none;border:1px solid var(--border);color:var(--text-secondary);border-radius:5px;padding:2px 8px;font-size:11px;cursor:pointer;transition:border-color .15s,color .15s}.sources-toggle:hover{border-color:var(--accent);color:var(--accent)}.sources-list{display:flex;flex-direction:column;gap:5px;margin-top:8px}.source-card{text-align:left;display:flex;flex-direction:column;gap:4px;padding:8px 10px;background:var(--bg-primary);border:1px solid var(--border);border-radius:8px;color:var(--text-primary);cursor:pointer;width:100%;transition:border-color .15s}.source-card:hover,.source-card.active{border-color:var(--accent)}.source-card-header{display:flex;align-items:center;justify-content:space-between;gap:8px}.source-card-header strong{color:var(--accent);font-size:11px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.source-page{font-size:10px;color:var(--text-secondary);background:var(--bg-secondary);padding:1px 5px;border-radius:4px;flex-shrink:0}.source-text{font-size:11px;color:var(--text-secondary);overflow:hidden;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}.chat-form{display:flex;gap:8px;padding:10px 12px;border-top:1px solid var(--border);align-items:flex-end;flex-shrink:0}.chat-form textarea{flex:1;min-height:40px;max-height:100px;resize:none;border-radius:10px;border:1px solid var(--border);background:var(--bg-secondary);color:var(--text-primary);padding:9px 12px;font-size:13px}.chat-form textarea:focus{outline:none;border-color:var(--accent)}.chat-form button{display:flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:10px;border:none;background:var(--accent);color:#fff;cursor:pointer;flex-shrink:0}.chat-form button:disabled{opacity:.4;cursor:not-allowed}.spin{animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@media (max-width: 1100px){.chat-layout{grid-template-columns:1fr;grid-template-rows:auto 1fr auto;height:auto}.chat-main{height:80vh}}