/* ── Reset & variables ───────────────────────────── */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    :root {
      --sidebar-w: 260px;
      --bg: #f8fafc;
      --card: #ffffff;
      --border: #e2e8f0;
      --text: #1e293b;
      --muted: #64748b;
      --primary: #3b82f6;
      --primary-hover: #2563eb;
      --danger: #ef4444;
      --success: #22c55e;
      --warning: #f59e0b;
      --sidebar-bg: #1e293b;
      --sidebar-text: #f1f5f9;
      --sidebar-muted: #94a3b8;
      --sidebar-hover: #334155;
      --radius: 8px;
      --shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
    }
    body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
           background: var(--bg); color: var(--text); font-size: 14px; line-height: 1.6; }

    /* ── Layout ─────────────────────────────────────── */
    #app { display: flex; min-height: 100vh; }
    .sidebar {
      width: var(--sidebar-w); flex-shrink: 0; background: var(--sidebar-bg);
      color: var(--sidebar-text); display: flex; flex-direction: column;
      position: fixed; top: 0; left: 0; bottom: 0; overflow-y: auto; z-index: 10;
    }
    .main { margin-left: var(--sidebar-w); flex: 1; display: flex; flex-direction: column;
            min-height: 100vh; }

    /* ── Sidebar internals ───────────────────────────── */
    .sidebar-header { padding: 20px 16px 12px; border-bottom: 1px solid #334155; }
    .sidebar-header h1 { font-size: 18px; font-weight: 700; letter-spacing: -.3px; }
    .sidebar-header p  { font-size: 11px; color: var(--sidebar-muted); margin-top: 2px; }
    .sidebar-section { padding: 12px 16px; border-bottom: 1px solid #334155; }
    .sidebar-section-title { font-size: 10px; font-weight: 600; text-transform: uppercase;
                              letter-spacing: .8px; color: var(--sidebar-muted); margin-bottom: 8px; }
    .status-row { display: flex; align-items: center; gap: 8px; font-size: 13px;
                  padding: 3px 0; }
    .dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
    .dot-green  { background: var(--success); }
    .dot-red    { background: var(--danger); }
    .dot-yellow { background: var(--warning); }
    .dot-gray   { background: var(--sidebar-muted); }
    .sidebar-label { font-size: 11px; color: var(--sidebar-muted); margin-bottom: 4px; }
    .sidebar-select {
      width: 100%; background: #334155; color: var(--sidebar-text);
      border: 1px solid #475569; border-radius: 6px; padding: 6px 8px;
      font-size: 13px; cursor: pointer;
    }
    .sidebar-select:focus { outline: 2px solid var(--primary); }
    .sidebar-footer { margin-top: auto; padding: 12px 16px;
                      border-top: 1px solid #334155; }
    .btn-ghost { width: 100%; background: none; border: 1px solid #475569;
                 color: var(--sidebar-text); padding: 7px 12px; border-radius: 6px;
                 font-size: 13px; cursor: pointer; display: flex; align-items: center;
                 gap: 6px; justify-content: center; }
    .btn-ghost:hover { background: var(--sidebar-hover); }

    /* ── Tabs ────────────────────────────────────────── */
    .tab-bar { display: flex; background: var(--card); border-bottom: 1px solid var(--border);
               padding: 0 24px; gap: 0; position: sticky; top: 0; z-index: 5; }
    .tab-btn { padding: 14px 18px; font-size: 13px; font-weight: 500; cursor: pointer;
               border: none; background: none; color: var(--muted); border-bottom: 2px solid transparent;
               transition: color .15s, border-color .15s; }
    .tab-btn:hover   { color: var(--text); }
    .tab-btn.active  { color: var(--primary); border-bottom-color: var(--primary); }

    /* ── Content area ────────────────────────────────── */
    .content { flex: 1; padding: 28px 32px; max-width: 960px; }

    /* ── Cards ───────────────────────────────────────── */
    .card { background: var(--card); border: 1px solid var(--border);
            border-radius: var(--radius); padding: 20px; margin-bottom: 16px;
            box-shadow: var(--shadow); }
    .card-title { font-size: 15px; font-weight: 600; margin-bottom: 12px; }

    /* ── Forms ───────────────────────────────────────── */
    label { display: block; font-size: 12px; font-weight: 500; color: var(--muted); margin-bottom: 4px; }
    input[type=text], input[type=number], select, textarea {
      width: 100%; border: 1px solid var(--border); border-radius: 6px;
      padding: 8px 10px; font-size: 13px; color: var(--text);
      background: var(--card); transition: border-color .15s;
    }
    input:focus, select:focus, textarea:focus {
      outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(59,130,246,.15);
    }
    textarea { resize: vertical; min-height: 80px; }
    .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
    .form-group { margin-bottom: 12px; }

    /* ── Buttons ─────────────────────────────────────── */
    .btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px;
           border-radius: 6px; font-size: 13px; font-weight: 500; cursor: pointer;
           border: none; transition: background .15s, opacity .15s; }
    .btn:disabled { opacity: .5; cursor: not-allowed; }
    .btn-primary  { background: var(--primary); color: #fff; }
    .btn-primary:hover:not(:disabled) { background: var(--primary-hover); }
    .btn-secondary { background: var(--bg); color: var(--text); border: 1px solid var(--border); }
    .btn-secondary:hover:not(:disabled) { background: var(--border); }
    .btn-danger   { background: var(--danger); color: #fff; }
    .btn-danger:hover:not(:disabled) { background: #dc2626; }

    /* ── Provider tabs ───────────────────────────────── */
    .provider-tabs { display: flex; gap: 6px; flex-wrap: wrap; }
    .provider-tab {
      padding: 6px 14px; font-size: 13px; border-radius: 6px; border: 1px solid var(--border);
      background: var(--bg); color: var(--muted); cursor: pointer; transition: all .15s;
    }
    .provider-tab:hover { background: var(--border); color: var(--text); }
    .provider-tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }
    .btn-sm { padding: 5px 10px; font-size: 12px; }
    .btn-block { width: 100%; justify-content: center; }

    /* ── Alerts ──────────────────────────────────────── */
    .alert { padding: 10px 14px; border-radius: 6px; font-size: 13px; margin-bottom: 16px;
             display: flex; align-items: flex-start; gap: 8px; }
    .alert-error   { background: #fef2f2; border: 1px solid #fca5a5; color: #991b1b; }
    .alert-success { background: #f0fdf4; border: 1px solid #86efac; color: #166534; }
    .alert-info    { background: #eff6ff; border: 1px solid #bfdbfe; color: #1e40af; }
    .alert-warning { background: #fffbeb; border: 1px solid #fde68a; color: #92400e; }
    .alert-close { margin-left: auto; cursor: pointer; opacity: .6; background: none;
                   border: none; font-size: 16px; line-height: 1; color: inherit; }
    .alert-close:hover { opacity: 1; }

    /* ── Badge / Tag ─────────────────────────────────── */
    .badge { display: inline-block; padding: 2px 8px; border-radius: 12px; font-size: 11px;
             font-weight: 500; }
    .badge-blue   { background: #dbeafe; color: #1e40af; }
    .badge-green  { background: #dcfce7; color: #166534; }
    .badge-gray   { background: #f1f5f9; color: var(--muted); }
    .badge-yellow { background: #fef9c3; color: #854d0e; }

    /* ── Spinner ─────────────────────────────────────── */
    .spinner { display: inline-block; width: 14px; height: 14px; border: 2px solid currentColor;
               border-top-color: transparent; border-radius: 50%; animation: spin .6s linear infinite; }
    @keyframes spin { to { transform: rotate(360deg); } }

    /* ── Table ───────────────────────────────────────── */
    .table-wrap { overflow-x: auto; }
    table { width: 100%; border-collapse: collapse; font-size: 13px; }
    th { text-align: left; padding: 8px 12px; font-size: 11px; font-weight: 600;
         text-transform: uppercase; color: var(--muted); border-bottom: 2px solid var(--border); }
    td { padding: 10px 12px; border-bottom: 1px solid var(--border); }
    tr:last-child td { border-bottom: none; }
    tr:hover td { background: var(--bg); }

    /* ── Misc helpers ────────────────────────────────── */
    .flex   { display: flex; }
    .items-center { align-items: center; }
    .gap-8  { gap: 8px; }
    .gap-12 { gap: 12px; }
    .mt-8   { margin-top: 8px; }
    .mt-16  { margin-top: 16px; }
    .mb-16  { margin-bottom: 16px; }
    .text-muted { color: var(--muted); }
    .text-sm    { font-size: 12px; }
    .font-mono  { font-family: 'SF Mono', 'Fira Code', monospace; }
    .divider { border: none; border-top: 1px solid var(--border); margin: 16px 0; }
    .page-title { font-size: 20px; font-weight: 700; margin-bottom: 4px; }
    .page-sub   { font-size: 13px; color: var(--muted); margin-bottom: 20px; }
    .empty-state { text-align: center; padding: 48px 16px; color: var(--muted); }
    .empty-state p { margin-top: 8px; font-size: 13px; }
    pre { background: var(--bg); border: 1px solid var(--border); border-radius: 6px;
          padding: 12px; font-size: 12px; overflow-x: auto; white-space: pre-wrap;
          word-break: break-all; font-family: 'SF Mono', 'Fira Code', monospace; }

    /* ── Collapsible ─────────────────────────────────── */
    .collapsible { border: 1px solid var(--border); border-radius: 6px; margin-bottom: 8px; }
    .collapsible-header { display: flex; align-items: center; justify-content: space-between;
                          padding: 10px 14px; cursor: pointer; font-weight: 500; font-size: 13px; }
    .collapsible-header:hover { background: var(--bg); border-radius: 6px; }
    .collapsible-body { padding: 0 14px 12px; font-size: 13px; }
    .chevron { transition: transform .2s; display: inline-block; }
    .chevron.open { transform: rotate(90deg); }

    /* ── Modal ───────────────────────────────────────── */
    .modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,.4);
                     z-index: 100; display: flex; align-items: center; justify-content: center; }
    .modal { background: var(--card); border-radius: var(--radius); padding: 24px;
             width: 460px; max-width: 95vw; max-height: 80vh; overflow-y: auto;
             box-shadow: 0 20px 60px rgba(0,0,0,.2); }
    .modal-title { font-size: 16px; font-weight: 600; margin-bottom: 20px; }
    .modal-footer { display: flex; justify-content: flex-end; gap: 8px; margin-top: 20px; }

    /* ── Progress bar ────────────────────────────────── */
    .progress-bar { height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; }
    .progress-fill { height: 100%; background: var(--primary); border-radius: 2px;
                     transition: width .3s ease; }

    /* ── File list ───────────────────────────────────── */
    .file-item { display: flex; align-items: center; justify-content: space-between;
                 padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px;
                 margin-bottom: 6px; background: var(--card); }
    .file-item:hover { border-color: var(--primary); }
    .file-name { font-size: 13px; font-weight: 500; }
    .file-meta { font-size: 11px; color: var(--muted); }
    .file-meta-panel { background: var(--bg); border-top: 1px solid var(--border);
                       padding: 12px 16px 14px; font-size: 13px; }
    .file-meta-title { font-size: 14px; font-weight: 600; margin-bottom: 6px; line-height: 1.4; }
    .file-meta-row   { display: flex; gap: 6px; align-items: baseline; margin-bottom: 3px;
                       font-size: 12px; color: var(--muted); }
    .file-meta-row strong { color: var(--text); font-weight: 500; }
    .badge-source    { display: inline-block; padding: 1px 7px; border-radius: 10px;
                       font-size: 11px; font-weight: 500; background: #eff6ff; color: #1d4ed8; }

    /* ── Citation box ────────────────────────────────── */
    .citation-box { background: var(--bg); border-left: 3px solid var(--primary);
                    padding: 10px 14px; border-radius: 0 6px 6px 0; margin-top: 8px; }

    /* ── Passage ─────────────────────────────────────── */
    .passage { border: 1px solid var(--border); border-radius: 6px; padding: 12px;
               margin-bottom: 8px; }
    .passage-score { font-size: 11px; color: var(--primary); font-weight: 600; }
    .passage-text { margin: 6px 0; line-height: 1.6; }
    .passage-meta  { font-size: 11px; color: var(--muted); }

    /* ── Checkbox toggle ─────────────────────────────── */
    .checkbox-label { display: flex; align-items: center; gap: 8px; cursor: pointer;
                      font-size: 13px; padding: 4px 0; }
    .checkbox-label input[type=checkbox] { width: 14px; height: 14px; cursor: pointer; }

    /* ── Radio ───────────────────────────────────────── */
    .radio-group { display: flex; flex-direction: column; gap: 6px; }
    .radio-label { display: flex; align-items: center; gap: 8px; cursor: pointer; font-size: 13px; }

    /* ── File picker panel ───────────────────────────── */
    .picker-panel {
      margin: 12px -20px -20px -20px;
      padding: 16px 20px;
      border-top: 1px solid var(--border);
      background: var(--bg);
      border-radius: 0 0 var(--radius) var(--radius);
    }
    .picker-filters { display: flex; gap: 8px; margin-bottom: 10px; }
    .picker-filters select { flex: 0 0 160px; }
    .picker-filters input  { flex: 1; }
    .picker-list {
      max-height: 260px; overflow-y: auto;
      border: 1px solid var(--border); border-radius: 6px; background: var(--card);
    }
    .picker-row {
      display: flex; align-items: center; gap: 8px;
      padding: 7px 12px; border-bottom: 1px solid var(--border);
      font-size: 13px; cursor: pointer;
    }
    .picker-row:last-child { border-bottom: none; }
    .picker-row:hover { background: var(--bg); }
    .picker-row input[type=checkbox] { width: 14px; height: 14px; cursor: pointer; flex-shrink: 0; }
    .picker-row-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
    .picker-dir-tag  { font-size: 11px; color: var(--muted); }
    .picker-status   { font-size: 12px; min-width: 16px; text-align: right; flex-shrink: 0; }

    @media (max-width: 768px) {
      .sidebar { width: 100%; position: relative; height: auto; }
      .main { margin-left: 0; }
      .form-row { grid-template-columns: 1fr; }
    }