:root {
    --ink: #1a1814;
    --ink-mid: #4a4640;
    --ink-light: #9a9490;
    --paper: #f7f4ef;
    --paper-mid: #ede9e2;
    --paper-dark: #ddd8cf;
    --accent: #8b3a2a;
    --accent-light: #c4735f;
    --accent-dim: #f0e0da;
    --success: #2a6b4a;
    --success-bg: #f0f7f3;
    --success-border: #b8d9c8;
    --warning: #7a5c1a;
    --warning-bg: #fdf5e0;
    --warning-border: #e8d090;
    --frame-1: #2a4a7a;
    --frame-2: #2a6b4a;
    --frame-3: #7a3a6a;
    --frame-4: #5a4a1a;
    --frame-5: #1a5a6b;
    --rule: #d0cbc2;
    --mono: 'JetBrains Mono', monospace;
    --serif: 'Spectral', Georgia, serif;
    --sans: 'Barlow', sans-serif;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }
  body { background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 15px; line-height: 1.6; min-height: 100vh; }

  header {
    border-bottom: 2px solid var(--ink); padding: 1.75rem 3rem 1.5rem;
    display: flex; align-items: baseline; gap: 2rem; flex-wrap: wrap;
  }
  .logo { font-family: var(--serif); font-weight: 300; font-size: 1.4rem; letter-spacing: -0.02em; }
  .logo em { font-style: italic; color: var(--accent); }
  .phase-tag {
    font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.12em;
    text-transform: uppercase; color: var(--paper); background: var(--accent);
    padding: 0.25rem 0.65rem; border-radius: 2px;
  }
  .nav-links { margin-left: auto; display: flex; gap: 1.5rem; }
  .nav-link {
    font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.08em;
    text-transform: uppercase; color: var(--ink-light); text-decoration: none;
    border-bottom: 1px solid transparent; transition: color 0.15s, border-color 0.15s;
  }
  .nav-link:hover { color: var(--accent); border-color: var(--accent); }

  .workspace { max-width: 1200px; margin: 0 auto; padding: 2.5rem 3rem; }

  .section-head {
    font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.15em;
    text-transform: uppercase; color: var(--ink-light); margin-bottom: 1.25rem;
    display: flex; align-items: center; gap: 0.75rem;
  }
  .section-head::after { content: ''; flex: 1; height: 1px; background: var(--rule); }

  /* ── Pyodide status ── */
  .pyodide-status {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1.25rem;
    border-radius: 3px; margin-bottom: 2rem; font-size: 0.82rem;
    font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.04em;
    border: 1px solid var(--rule); background: white;
  }
  .pyodide-status.loading { color: var(--warning); border-color: var(--warning-border); background: var(--warning-bg); }
  .pyodide-status.ready   { color: var(--success); border-color: var(--success-border); background: var(--success-bg); }
  .pyodide-status.error   { color: var(--accent);  border-color: #e8b4aa; background: #fdf0ee; }
  .py-spinner { width: 14px; height: 14px; border: 2px solid var(--warning-border); border-top-color: var(--warning); border-radius: 50%; animation: spin 0.7s linear infinite; flex-shrink: 0; }
  @keyframes spin { to { transform: rotate(360deg); } }

  /* ── Upload zone ── */
  .upload-zone {
    border: 2px dashed var(--paper-dark); border-radius: 4px; padding: 1.5rem 2rem;
    display: flex; align-items: center; gap: 1.5rem; background: white; cursor: pointer;
    transition: border-color 0.2s, background 0.2s; position: relative; margin-bottom: 1.5rem;
  }
  .upload-zone:hover, .upload-zone.drag-over { border-color: var(--accent-light); background: #fdf9f7; }
  .upload-zone.loaded { border-style: solid; border-color: var(--success); background: var(--success-bg); cursor: default; }
  .upload-zone input { position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; height: 100%; }
  .upload-zone.loaded input { pointer-events: none; }
  .upload-icon { font-size: 1.8rem; flex-shrink: 0; color: var(--ink-light); }
  .upload-zone.loaded .upload-icon { color: var(--success); }
  .upload-body strong { display: block; font-size: 0.88rem; color: var(--ink); margin-bottom: 0.2rem; }
  .upload-zone.loaded .upload-body strong { color: var(--success); }
  .upload-sub { font-family: var(--mono); font-size: 0.65rem; color: var(--ink-light); }
  .upload-stats { font-family: var(--mono); font-size: 0.68rem; color: var(--ink-light); margin-top: 0.5rem; }
  .upload-clear { position: absolute; top: 0.5rem; right: 0.6rem; background: none; border: none; cursor: pointer; color: var(--ink-light); font-size: 0.85rem; }
  .upload-clear:hover { color: var(--accent); }

  /* ── Step cards ── */
  .step-card {
    background: white; border: 1px solid var(--rule); border-radius: 4px;
    margin-bottom: 1.5rem; overflow: hidden;
  }
  .step-card-header {
    padding: 1rem 1.5rem; border-bottom: 1px solid var(--paper-mid);
    display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem;
  }
  .step-card-title {
    display: flex; align-items: center; gap: 0.75rem;
  }
  .step-num {
    font-family: var(--mono); font-size: 0.6rem; letter-spacing: 0.1em;
    text-transform: uppercase; background: var(--ink); color: var(--paper);
    padding: 0.2rem 0.5rem; border-radius: 2px;
  }
  .step-num.done { background: var(--success); }
  .step-num.active { background: var(--accent); }
  .step-name { font-weight: 600; font-size: 0.9rem; color: var(--ink); }
  .step-card-body { padding: 1.25rem 1.5rem; }

  /* ── Stats row ── */
  .stats-row { display: flex; gap: 1.5rem; flex-wrap: wrap; margin-bottom: 1rem; }
  .stat-item { display: flex; flex-direction: column; gap: 0.1rem; }
  .stat-val { font-family: var(--mono); font-size: 1.1rem; font-weight: 500; color: var(--ink); }
  .stat-label { font-family: var(--mono); font-size: 0.6rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-light); }

  /* ── Threshold controls ── */
  .threshold-modes {
    display: flex; gap: 0; border: 1px solid var(--paper-dark);
    border-radius: 3px; overflow: hidden; margin-bottom: 1.25rem;
  }
  .tmode-opt { flex: 1; position: relative; }
  .tmode-opt input { position: absolute; opacity: 0; width: 0; }
  .tmode-opt label {
    display: flex; flex-direction: column; align-items: center; gap: 0.2rem;
    padding: 0.65rem 0.75rem; cursor: pointer; background: white;
    font-family: var(--sans); font-size: 0.75rem; font-weight: 500;
    letter-spacing: 0.03em; border-right: 1px solid var(--paper-dark);
    transition: background 0.15s, color 0.15s; text-align: center; margin: 0;
  }
  .tmode-opt:last-child label { border-right: none; }
  .tmode-opt label span.tmode-sub { font-size: 0.62rem; color: var(--ink-light); font-weight: 400; font-family: var(--mono); }
  .tmode-opt input:checked + label { background: var(--ink); color: var(--paper); }
  .tmode-opt input:checked + label .tmode-sub { color: var(--paper-dark); }

  .slider-row {
    display: flex; align-items: center; gap: 1rem; margin-bottom: 1.25rem;
    padding: 0.85rem 1rem; background: var(--paper); border-radius: 3px;
    border: 1px solid var(--rule);
  }
  .slider-label { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-mid); white-space: nowrap; }
  .slider-track { flex: 1; }
  input[type="range"].threshold-slider {
    width: 100%; height: 4px; -webkit-appearance: none; appearance: none;
    background: var(--paper-dark); border-radius: 2px; outline: none; cursor: pointer;
  }
  input[type="range"].threshold-slider::-webkit-slider-thumb {
    -webkit-appearance: none; width: 16px; height: 16px; border-radius: 50%;
    background: var(--accent); cursor: pointer; border: 2px solid white;
    box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  }
  input[type="range"].threshold-slider::-moz-range-thumb {
    width: 16px; height: 16px; border-radius: 50%; background: var(--accent);
    cursor: pointer; border: 2px solid white;
  }
  .slider-val {
    font-family: var(--mono); font-size: 0.88rem; font-weight: 500;
    color: var(--accent); min-width: 2.5rem; text-align: center;
  }
  .slider-tick-labels {
    display: flex; justify-content: space-between;
    font-family: var(--mono); font-size: 0.58rem; color: var(--ink-light);
    margin-top: 0.25rem; padding: 0 1px;
  }

  /* ── Bin stats grid ── */
  .bin-stats-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 0.75rem; margin-bottom: 1.25rem;
  }
  .bin-stat-card {
    background: white; border: 1px solid var(--rule); border-radius: 3px;
    padding: 0.75rem 1rem;
  }
  .bin-stat-card.warn { border-color: var(--warning-border); background: var(--warning-bg); }
  .bin-stat-card.good { border-color: var(--success-border); background: var(--success-bg); }
  .bsc-val { font-family: var(--mono); font-size: 1.2rem; font-weight: 500; color: var(--ink); line-height: 1; margin-bottom: 0.2rem; }
  .bsc-val.warn { color: var(--warning); }
  .bsc-val.good { color: var(--success); }
  .bsc-label { font-family: var(--mono); font-size: 0.58rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-light); line-height: 1.3; }

  /* ── Calibration criteria ── */
  .calibration-checks { display: flex; flex-direction: column; gap: 0.4rem; margin-bottom: 1.25rem; }
  .cal-check {
    display: flex; align-items: center; gap: 0.6rem;
    font-family: var(--sans); font-size: 0.78rem; color: var(--ink-mid);
  }
  .cal-icon { font-size: 0.85rem; flex-shrink: 0; width: 1.2rem; text-align: center; }

  /* ── Heatmap ── */
  .heatmap-section { margin-bottom: 1.25rem; }
  .heatmap-header {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 0.5rem; flex-wrap: wrap; gap: 0.5rem;
  }
  .heatmap-label { font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-light); }
  .heatmap-legend { display: flex; align-items: center; gap: 0.75rem; }
  .legend-item { display: flex; align-items: center; gap: 0.35rem; font-family: var(--mono); font-size: 0.6rem; color: var(--ink-light); }
  .legend-swatch { width: 12px; height: 12px; border-radius: 2px; flex-shrink: 0; }
  .heatmap-wrap { overflow-x: auto; border: 1px solid var(--rule); border-radius: 3px; background: white; }
  canvas#dtm-heatmap { display: block; image-rendering: pixelated; }
  .heatmap-note { font-family: var(--serif); font-style: italic; font-size: 0.72rem; color: var(--ink-light); margin-top: 0.35rem; }

  .confirm-bin-row { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; padding-top: 0.5rem; border-top: 1px solid var(--rule); }
  .confirm-bin-note { font-family: var(--serif); font-style: italic; font-size: 0.82rem; color: var(--ink-light); }

  /* ── Cluster controls ── */
  .cluster-controls {
    display: flex; align-items: center; gap: 1rem; margin-bottom: 1.25rem; flex-wrap: wrap;
  }
  .cluster-label { font-size: 0.8rem; font-weight: 600; color: var(--ink-mid); text-transform: uppercase; letter-spacing: 0.04em; }
  .cluster-stepper { display: flex; align-items: center; gap: 0; border: 1px solid var(--paper-dark); border-radius: 3px; overflow: hidden; }
  .cluster-stepper button {
    background: white; border: none; padding: 0.45rem 0.75rem; cursor: pointer;
    font-family: var(--mono); font-size: 0.9rem; color: var(--ink-mid);
    transition: background 0.15s; border-right: 1px solid var(--paper-dark);
  }
  .cluster-stepper button:last-child { border-right: none; }
  .cluster-stepper button:hover { background: var(--paper-mid); }
  .cluster-stepper span { padding: 0.45rem 1rem; font-family: var(--mono); font-size: 0.88rem; font-weight: 500; color: var(--ink); border-right: 1px solid var(--paper-dark); background: var(--paper); }

  /* ── Action buttons ── */
  .btn {
    border: none; border-radius: 3px; padding: 0.7rem 1.5rem; font-family: var(--sans);
    font-size: 0.82rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
    cursor: pointer; transition: background 0.15s, transform 0.1s;
  }
  .btn:active:not(:disabled) { transform: translateY(1px); }
  .btn:disabled { opacity: 0.4; cursor: not-allowed; }
  .btn-primary { background: var(--ink); color: var(--paper); }
  .btn-primary:hover:not(:disabled) { background: var(--accent); }
  .btn-success { background: var(--success); color: white; }
  .btn-success:hover:not(:disabled) { background: #1a5a3a; }
  .btn-outline { background: none; border: 1px solid var(--paper-dark); color: var(--ink-mid); }
  .btn-outline:hover:not(:disabled) { border-color: var(--ink); color: var(--ink); background: var(--paper); }

  .btn-row { display: flex; gap: 0.75rem; flex-wrap: wrap; margin-top: 1rem; }

  /* ── TTM table ── */
  .matrix-wrap { overflow: auto; max-height: 400px; border: 1px solid var(--rule); border-radius: 3px; }
  .matrix-table { border-collapse: collapse; font-size: 0.68rem; white-space: nowrap; min-width: 100%; }
  .matrix-table thead { position: sticky; top: 0; z-index: 2; }
  .matrix-table th {
    background: var(--ink); color: var(--paper); padding: 0.4rem 0.5rem;
    font-family: var(--mono); font-size: 0.55rem; letter-spacing: 0.06em; text-transform: uppercase;
    text-align: center; border-right: 1px solid #333; font-weight: 400;
  }
  .matrix-table th:first-child { text-align: left; min-width: 160px; position: sticky; left: 0; background: var(--ink); }
  .matrix-table tbody tr:nth-child(even) { background: #fafaf8; }
  .matrix-table tbody tr:hover { background: var(--accent-dim); }
  .matrix-table td {
    padding: 0.35rem 0.5rem; border-right: 1px solid var(--paper-mid);
    text-align: center; font-family: var(--mono); color: var(--ink-mid);
    border-bottom: 1px solid var(--paper-mid);
  }
  .matrix-table td:first-child {
    text-align: left; position: sticky; left: 0; background: white; font-weight: 500;
    color: var(--ink); z-index: 1;
  }
  .matrix-table tbody tr:hover td:first-child { background: var(--accent-dim); }
  .ttm-high { color: var(--accent) !important; font-weight: 700; }
  .ttm-mid  { color: var(--ink) !important; font-weight: 500; }
  .ttm-zero { color: var(--paper-dark) !important; }

  /* ── Cluster results ── */
  .cluster-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1rem; margin-bottom: 1.5rem; }
  .cluster-card { border: 1px solid var(--rule); border-radius: 4px; overflow: hidden; }
  .cluster-card-header {
    padding: 0.75rem 1rem; display: flex; align-items: center;
    justify-content: space-between; border-bottom: 1px solid var(--paper-mid);
  }
  .cluster-card-name { font-weight: 600; font-size: 0.88rem; }
  .cluster-card-count { font-family: var(--mono); font-size: 0.65rem; color: var(--ink-light); }
  .cluster-card-body { padding: 0.75rem 1rem; }
  .concept-tag {
    display: inline-block; font-family: var(--mono); font-size: 0.62rem;
    padding: 0.15rem 0.45rem; border-radius: 2px; margin: 0.15rem; line-height: 1.4;
  }

  /* Frame colours */
  .frame-0 { background: #eef3fa; color: var(--frame-1); border: 1px solid #b0c4e0; }
  .frame-1 { background: var(--success-bg); color: var(--frame-2); border: 1px solid var(--success-border); }
  .frame-2 { background: #f9eef6; color: var(--frame-3); border: 1px solid #d9b0d0; }
  .frame-3 { background: var(--warning-bg); color: var(--frame-4); border: 1px solid var(--warning-border); }
  .frame-4 { background: #eef7f9; color: var(--frame-5); border: 1px solid #a8d4de; }

  .cluster-card-header.frame-0 { background: #eef3fa; }
  .cluster-card-header.frame-1 { background: var(--success-bg); }
  .cluster-card-header.frame-2 { background: #f9eef6; }
  .cluster-card-header.frame-3 { background: var(--warning-bg); }
  .cluster-card-header.frame-4 { background: #eef7f9; }

  /* ── Inertia / quality indicator ── */
  .quality-bar-wrap { margin-bottom: 1rem; }
  .quality-label { font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-light); margin-bottom: 0.35rem; display: flex; justify-content: space-between; }
  .quality-bar-track { height: 6px; background: var(--paper-dark); border-radius: 3px; overflow: hidden; }
  .quality-bar-fill { height: 100%; background: var(--success); border-radius: 3px; transition: width 0.6s ease; }
  .quality-note { font-family: var(--serif); font-style: italic; font-size: 0.78rem; color: var(--ink-light); margin-top: 0.35rem; }

  /* ── Frame naming ── */
  .frame-naming-grid { display: flex; flex-direction: column; gap: 1rem; }
  .frame-name-row {
    display: grid; grid-template-columns: 120px 1fr 1fr;
    gap: 1rem; align-items: start; padding: 1rem;
    border: 1px solid var(--rule); border-radius: 3px; background: white;
  }
  .frame-badge {
    font-family: var(--mono); font-size: 0.72rem; font-weight: 500;
    padding: 0.35rem 0.75rem; border-radius: 3px; text-align: center;
  }
  .frame-name-input {
    width: 100%; border: 1px solid var(--paper-dark); border-radius: 3px;
    padding: 0.5rem 0.75rem; font-family: var(--sans); font-size: 0.85rem;
    color: var(--ink); outline: none; transition: border-color 0.15s;
  }
  .frame-name-input:focus { border-color: var(--ink-mid); }
  .frame-llm-name {
    font-family: var(--serif); font-style: italic; font-size: 0.82rem;
    color: var(--ink-mid); padding: 0.5rem 0;
  }

  /* ── Representative docs ── */
  .rep-docs-list { margin-top: 0.5rem; }
  .rep-doc-item {
    display: flex; align-items: baseline; gap: 0.5rem; padding: 0.3rem 0;
    border-bottom: 1px solid var(--paper-mid); font-size: 0.75rem;
  }
  .rep-doc-item:last-child { border-bottom: none; }
  .rep-doc-score { font-family: var(--mono); font-size: 0.68rem; color: var(--accent); flex-shrink: 0; }
  .rep-doc-name { color: var(--ink-mid); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

  /* ── Error ── */
  .error-box { background: #fdf0ee; border: 1px solid #e8b4aa; border-radius: 3px; padding: 1rem 1.25rem; color: var(--accent); font-size: 0.82rem; margin-bottom: 1rem; }
  .error-box strong { display: block; font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: 0.25rem; }

  .callout { background: white; border-left: 3px solid var(--accent); padding: 1rem 1.25rem; margin-bottom: 2rem; font-family: var(--serif); font-size: 0.88rem; line-height: 1.7; color: var(--ink-mid); }
  .callout strong { color: var(--ink); font-family: var(--sans); font-size: 0.82rem; }

  @media (max-width: 800px) {
    .workspace { padding: 1.5rem; }
    header { padding: 1.25rem 1.5rem; }
    .frame-name-row { grid-template-columns: 1fr; }
  }

  /* ── Shared navigation ── */
  .cr-nav { border-bottom: 2px solid var(--ink); padding: 1rem 2rem; display: flex; align-items: center; gap: 1.5rem; flex-wrap: wrap; }
  .cr-nav-logo { font-family: var(--serif); font-weight: 300; font-size: 1.1rem; letter-spacing: -0.02em; text-decoration: none; color: var(--ink); flex-shrink: 0; }
  .cr-nav-logo em { font-style: italic; color: var(--accent); }
  .cr-phases { display: flex; align-items: center; gap: 0; }
  .cr-phase-link { font-family: var(--mono); font-size: 0.6rem; letter-spacing: 0.07em; text-transform: uppercase; text-decoration: none; padding: 0.3rem 0.65rem; border: 1px solid var(--paper-dark); border-right: none; color: var(--ink-light); transition: background 0.15s, color 0.15s; white-space: nowrap; }
  .cr-phase-link:first-child { border-radius: 3px 0 0 3px; }
  .cr-phase-link:last-child { border-right: 1px solid var(--paper-dark); border-radius: 0 3px 3px 0; }
  .cr-phase-link:hover { background: var(--paper-mid); color: var(--ink); }
  .cr-phase-link.current { background: var(--ink); color: var(--paper); border-color: var(--ink); }
  .cr-nav-home { margin-left: auto; font-family: var(--mono); font-size: 0.6rem; letter-spacing: 0.08em; text-transform: uppercase; text-decoration: none; color: var(--ink-light); border-bottom: 1px solid transparent; transition: color 0.15s, border-color 0.15s; }
  .cr-nav-home:hover { color: var(--accent); border-color: var(--accent); }
  .cr-bottom-nav { border-top: 1px solid var(--rule); padding: 1.5rem 2rem; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 1rem; margin-top: 3rem; background: white; }
  .cr-bottom-btn { font-family: var(--mono); font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; text-decoration: none; color: var(--ink-mid); padding: 0.5rem 1rem; border: 1px solid var(--paper-dark); border-radius: 3px; transition: all 0.15s; }
  .cr-bottom-btn:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
  .cr-bottom-btn.ghost { opacity: 0.25; pointer-events: none; }
  .cr-bottom-center { font-family: var(--mono); font-size: 0.62rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-light); text-align: center; }