:root {
      --bg: #f0f2f5;
      --panel: #ffffff;
      --line: #e2e8f0;
      --line-strong: #94a3b8;
      --text: #0f172a;
      --muted: #64748b;
      --primary: #2563eb;
      --primary-hover: #1d4ed8;
      --primary-light: #dbeafe;
      --primary-glow: rgba(37, 99, 235, 0.15);
      --danger: #ef4444;
      --danger-hover: #dc2626;
      --success: #10b981;
      --warning: #f59e0b;
      --radius: 12px;
      --radius-sm: 12px;
      --radius-lg: 12px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-md: 0 4px 12px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
      --shadow-lg: 0 12px 32px rgba(0,0,0,0.1), 0 4px 8px rgba(0,0,0,0.06);
      --shadow-glow: 0 0 0 3px var(--primary-glow);
      --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
      --header-bg: #1e3a5f;
      --table-head-bg: #aec6db;
      --table-head-border: #6f8aa3;
      --table-cell-border: #3e4a57;
      --group-basic: #efefef;
      --group-melt: #dbe7cf;
      --group-warm: #f4dccb;
      --group-flex: #f6ebbf;
      --group-impact: #b5c3e0;
      --group-extra: #edf1f6;
    }

    * { box-sizing: border-box; margin: 0; }

    html, body {
      height: 100%;
      background: var(--bg);
      color: var(--text);
      font-family: "Inter", "SF Pro Display", -apple-system, "Microsoft YaHei", sans-serif;
      font-size: 14px;
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

    body {
      padding: 12px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      gap: 12px;
      min-height: 100vh;
    }

    /* ─── Layout ─── */
    .app {
      flex: 1 1 auto;
      min-height: 0;
      display: grid;
      grid-template-columns: 340px 1fr;
      gap: 12px;
      width: 100%;
    }

    .panel {
      background: var(--panel);
      border: none;
      border-radius: var(--radius-lg);
      box-shadow: inset 0 0 0 1px var(--line), var(--shadow-sm);
      overflow: hidden;
      min-height: 0;
      transition: box-shadow var(--transition);
    }

    .panel:hover {
      box-shadow: inset 0 0 0 1px var(--line-strong), var(--shadow-md);
    }

    .sidebar, .main {
      padding: 16px;
      min-height: 0;
    }

    .sidebar {
      display: flex;
      flex-direction: column;
      gap: 12px;
      overflow: auto;
    }

    .main {
      display: flex;
      flex-direction: column;
      gap: 12px;
      overflow: hidden;
    }

    /* ─── Sections ─── */
    .section {
      border: none;
      border-radius: var(--radius);
      padding: 14px;
      background: #fff;
      box-shadow: inset 0 0 0 1px #e8e8e8;
      transition: box-shadow var(--transition);
    }

    .section:hover {
      box-shadow: inset 0 0 0 1px #cbd5e1;
    }

    .section h2 {
      margin: 0 0 12px;
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 0.02em;
      color: #333;
      text-transform: uppercase;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .section h2::before {
      content: '';
      width: 3px;
      height: 14px;
      background: #409eff;
      border-radius: var(--radius);
    }

    .section-title {
      font-size: 12px;
      font-weight: 700;
      color: #1e293b;
    }

    /* ─── Fields ─── */
    .field {
      margin-bottom: 12px;
    }

    .field:last-child {
      margin-bottom: 0;
    }

    .field label {
      display: block;
      margin-bottom: 6px;
      color: var(--muted);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.01em;
    }

    input[type="url"],
    input[type="password"],
    select {
      width: 100%;
      height: 40px;
      border: none;
      border-radius: var(--radius-sm);
      padding: 0 12px;
      font: inherit;
      font-size: 13px;
      color: inherit;
      background: #fff;
      box-shadow: inset 0 0 0 1.5px var(--line);
      transition: box-shadow var(--transition);
      outline: none;
    }

    input[type="url"]:focus,
    input[type="password"]:focus,
    select:focus {
      box-shadow: inset 0 0 0 1.5px var(--primary), var(--shadow-glow);
    }

    input[type="url"]:hover:not(:focus),
    input[type="password"]:hover:not(:focus),
    select:hover:not(:focus) {
      box-shadow: inset 0 0 0 1.5px var(--line-strong);
    }

    /* Custom model dropdown */
    .model-select {
      position: relative;
      width: 100%;
    }

    .model-select-trigger {
      width: 100%;
      height: 42px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      padding: 0 14px;
      border: none;
      border-radius: var(--radius);
      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);
      color: var(--text);
      box-shadow: inset 0 0 0 1.5px #d5ddec, 0 1px 2px rgba(15, 23, 42, 0.03);
      cursor: pointer;
      transition: box-shadow var(--transition), background var(--transition);
      text-align: left;
      transform: none;
    }

    .model-select-trigger:hover:not(:disabled) {
      box-shadow: inset 0 0 0 1.5px var(--line-strong), 0 1px 2px rgba(15, 23, 42, 0.03);
      transform: none;
    }

    .model-select-trigger:active:not(:disabled) {
      transform: none;
      box-shadow: inset 0 0 0 1.5px var(--line-strong), 0 2px 6px rgba(15, 23, 42, 0.05);
    }

    .model-select-trigger:focus-visible {
      outline: none;
      box-shadow: inset 0 0 0 1.5px var(--primary), var(--shadow-glow);
    }

    .model-select-label {
      flex: 1 1 auto;
      min-width: 0;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      font-size: 13px;
      line-height: 1;
      color: inherit;
    }

    .model-select-caret {
      flex: 0 0 auto;
      width: 10px;
      height: 10px;
      position: relative;
      margin-left: 4px;
    }

    .model-select-caret::before,
    .model-select-caret::after {
      content: '';
      position: absolute;
      top: 4px;
      width: 7px;
      height: 2px;
      background: #64748b;
      border-radius: 999px;
      transition: transform var(--transition), background var(--transition);
    }

    .model-select-caret::before {
      left: -1px;
      transform: rotate(40deg);
    }

    .model-select-caret::after {
      right: -1px;
      transform: rotate(-40deg);
    }

    .model-select.open .model-select-caret::before {
      transform: rotate(-40deg);
    }

    .model-select.open .model-select-caret::after {
      transform: rotate(40deg);
    }

    .model-select-menu {
      position: absolute;
      inset: calc(100% + 8px) 0 auto 0;
      z-index: 20;
      display: none;
      flex-direction: column;
      padding: 6px;
      border-radius: var(--radius);
      background: rgba(255, 255, 255, 0.98);
      box-shadow: inset 0 0 0 1px #d8e1ec, 0 18px 40px rgba(15, 23, 42, 0.12);
      backdrop-filter: blur(10px);
      max-height: 260px;
      overflow: auto;
    }

    .model-select.open .model-select-menu {
      display: flex;
      gap: 6px;
    }

    .model-select-option {
      display: flex;
      align-items: center;
      width: 100%;
      height: auto;
      min-height: 52px;
      padding: 10px 12px;
      border: 1px solid transparent;
      border-radius: calc(var(--radius) - 2px);
      background: transparent;
      color: #0f172a;
      font: inherit;
      font-size: 13px;
      text-align: left;
      cursor: pointer;
      transition: background var(--transition), border-color var(--transition), color var(--transition);
      transform: none;
    }

    .model-select-option-inner {
      display: flex;
      flex-direction: column;
      gap: 3px;
      min-width: 0;
      width: 100%;
    }

    .model-select-option-name {
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      font-weight: 600;
      line-height: 1.2;
    }

    .model-select-option-meta {
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      color: #64748b;
      font-size: 11px;
      font-weight: 500;
      line-height: 1.2;
    }

    .model-select-option:hover:not(:disabled) {
      background: #eff6ff;
      border-color: #bfdbfe;
      box-shadow: none;
      transform: none;
    }

    .model-select-option:active:not(:disabled) {
      transform: none;
      box-shadow: none;
    }

    .model-select-option.active {
      background: linear-gradient(180deg, #dbeafe 0%, #bfdbfe 100%);
      border-color: #93c5fd;
      color: #0f172a;
      font-weight: 700;
    }

    .model-select-empty {
      padding: 10px 12px;
      color: #64748b;
      font-size: 13px;
    }

    .model-select.is-loading .model-select-trigger {
      color: #64748b;
    }

    .row {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      align-items: center;
    }

    /* ─── Buttons ─── */
    button {
      height: 40px;
      padding: 0 16px;
      border: 1.5px solid var(--line);
      border-radius: var(--radius-sm);
      font: inherit;
      font-size: 13px;
      font-weight: 600;
      background: #fff;
      color: var(--text);
      cursor: pointer;
      transition: all var(--transition);
      position: relative;
      overflow: hidden;
    }

    button:hover:not(:disabled) {
      border-color: var(--line-strong);
      background: #f8fafc;
      box-shadow: none;
    }

    button:active:not(:disabled) {
      box-shadow: none;
    }

    button:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    .btn-primary {
      border: none;
      background: linear-gradient(135deg, var(--primary), #3b82f6);
      color: #fff;
      box-shadow: inset 0 0 0 1.5px var(--primary), 0 2px 8px rgba(37, 99, 235, 0.3);
    }

    .btn-primary:hover:not(:disabled) {
      background: linear-gradient(135deg, var(--primary-hover), var(--primary));
      box-shadow: inset 0 0 0 1.5px var(--primary-hover), 0 2px 8px rgba(37, 99, 235, 0.3);
    }

    .btn-status {
      flex: 0 0 auto;
      padding: 0 16px;
      border: none;
      border-radius: var(--radius-sm);
      background: #fff;
      color: #475569;
      font: inherit;
      font-size: 13px;
      font-weight: 600;
      cursor: default;
      box-shadow: inset 0 0 0 1.5px #cbd5e1;
      transform: none;
      pointer-events: none;
      white-space: nowrap;
    }

    .btn-status.connected {
      box-shadow: inset 0 0 0 1.5px #86efac;
      color: #166534;
    }

    .btn-status.error {
      box-shadow: inset 0 0 0 1.5px #fca5a5;
      color: #991b1b;
    }

    .btn-danger {
      color: var(--danger);
      border: none;
      box-shadow: inset 0 0 0 1.5px #fecaca;
    }

    .btn-danger:hover:not(:disabled) {
      background: #fef2f2;
      box-shadow: inset 0 0 0 1.5px var(--danger);
    }

    .btn-icon {
      width: 40px;
      padding: 0;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    /* ─── File Upload ─── */
    .file-box {
      position: relative;
      display: block;
      min-height: 220px;
      border: none;
      border-radius: var(--radius);
      padding: 12px;
      background: linear-gradient(135deg, #f8fafc, #f1f5f9);
      box-shadow: inset 0 0 0 2px #cbd5e1;
      cursor: pointer;
      overflow: hidden;
      transition: all var(--transition);
    }

    .file-box:hover {
      box-shadow: inset 0 0 0 2px var(--primary);
      background: linear-gradient(135deg, #eff6ff, #dbeafe);
    }

    .file-box input[type="file"] {
      position: absolute;
      inset: 0;
      opacity: 0;
      cursor: pointer;
    }

    .file-box.has-image {
      box-shadow: inset 0 0 0 2px var(--primary);
    }

    .file-box strong {
      display: flex;
      align-items: center;
      gap: 6px;
      margin-bottom: 8px;
      font-size: 12px;
      font-weight: 700;
      color: var(--muted);
      text-transform: uppercase;
      letter-spacing: 0.04em;
    }

    .file-box strong::before {
      content: '📷';
      font-size: 14px;
    }

    .preview {
      min-height: 160px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-sm);
      background: #fff;
      box-shadow: inset 0 0 0 1px var(--line);
      overflow: hidden;
      transition: box-shadow var(--transition);
    }

    .file-box.has-image .preview {
      box-shadow: inset 0 0 0 1px var(--line), var(--shadow-sm);
    }

    .preview img {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: contain;
    }

    .preview.is-revealing img {
      transform-origin: center center;
      animation: previewReveal 0.36s cubic-bezier(0.16, 1, 0.3, 1);
      will-change: opacity, transform;
    }

    .muted {
      color: var(--muted);
      font-size: 12px;
    }

    /* ─── Table Section ─── */
    .table-section {
      flex: 0 0 auto;
      display: flex;
      flex-direction: column;
      min-height: 0;
      overflow: hidden;
    }

    #tableSection {
      padding: 0;
    }

    .table-meta {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 8px;
      margin-bottom: 10px;
      padding: 9px 12px;
      background: linear-gradient(180deg, #f7f9fc 0%, #edf2f7 100%);
      border: none;
      border-radius: var(--radius);
      font-size: 12px;
      color: #4b5563;
      box-shadow: inset 0 0 0 1px #d4dde7;
    }

    .table-title {
      font-size: 13px;
      font-weight: 700;
      color: #1f2937;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .table-title::before {
      content: '📊';
    }

    .table-wrap {
      flex: 0 1 auto;
      min-height: 120px;
      border: none;
      border-radius: var(--radius);
      overflow-x: auto;
      overflow-y: hidden;
      background: #fff;
      box-shadow: inset 0 0 0 1px var(--table-head-border);
    }

    .report-table {
      width: 100%;
      min-width: 980px;
      border-collapse: collapse;
      table-layout: fixed;
    }

    .report-table thead th {
      position: sticky;
      top: 0;
      z-index: 2;
      padding: 8px 6px;
      border: 1px solid var(--table-head-border);
      background: linear-gradient(180deg, #bfd4e4 0%, var(--table-head-bg) 100%);
      color: #0f172a;
      font-size: 12px;
      font-weight: 700;
      text-align: center;
      white-space: nowrap;
    }

    .report-table td {
      border: 1px solid var(--table-cell-border);
      text-align: center;
      vertical-align: middle;
      color: #111827;
      font-size: 13px;
      line-height: 1.4;
      padding: 6px 6px;
      font-variant-numeric: tabular-nums;
      background: #fff;
      transition: filter var(--transition), box-shadow var(--transition);
    }

    .report-table tbody tr:hover td {
      filter: brightness(0.98);
      box-shadow: inset 0 0 0 999px rgba(255, 255, 255, 0.08);
    }

    .report-table tbody tr.record-start td {
      border-top-width: 2px;
      border-top-color: #26323f;
    }

    .report-table td.group-basic {
      background: var(--group-basic);
      font-weight: 700;
    }

    .report-table td.group-melt {
      color: #111827;
      font-weight: 500;
      background: var(--group-melt);
    }

    .report-table td.group-tensile,
    .report-table td.group-elongation {
      background: var(--group-warm);
    }

    .report-table td.group-flexural,
    .report-table td.group-modulus {
      color: #111827;
      font-weight: 500;
      background: var(--group-flex);
    }

    .report-table td.group-impact {
      color: #111827;
      font-weight: 500;
      background: var(--group-impact);
    }

    .report-table td.group-extra {
      background: var(--group-extra);
    }

    .empty-cell {
      color: #bbb;
    }

    /* ─── Empty State ─── */
    .empty-panel {
      flex: 1 1 auto;
      min-height: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 12px;
      border: none;
      border-radius: var(--radius);
      color: #999;
      background: #fafafa;
      box-shadow: inset 0 0 0 1px #ccc;
      text-align: center;
      padding: 24px;
    }

    .empty-panel .empty-icon {
      font-size: 48px;
      opacity: 0.5;
    }

    .empty-panel .empty-text {
      font-size: 14px;
      font-weight: 500;
      max-width: 280px;
      line-height: 1.6;
    }

    /* ─── Output ─── */
    .output-section {
      flex: 1 1 auto;
      display: flex;
      flex-direction: column;
      min-height: 0;
      overflow: hidden;
    }

    .output-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      margin: 0 0 10px;
    }

    .output-section h1 {
      margin: 0;
      font-size: 13px;
      font-weight: 700;
      color: #333;
      text-transform: uppercase;
      letter-spacing: 0.02em;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .output-section h1::before {
      content: '';
      width: 3px;
      height: 14px;
      background: #409eff;
      border-radius: var(--radius);
    }

    .output-split {
      flex: 1 1 auto;
      min-height: 0;
      display: grid;
      grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
      gap: 12px;
    }

    .output-pane {
      display: flex;
      flex-direction: column;
      min-height: 0;
      gap: 8px;
      padding: 12px;
      border: none;
      border-radius: var(--radius);
      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);
      box-shadow: inset 0 0 0 1px #d8e1ec, 0 1px 2px rgba(15, 23, 42, 0.03);
    }

    .pane-title {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0.02em;
      color: #1f2937;
      text-transform: uppercase;
    }

    .pane-title::before {
      content: '';
      width: 3px;
      height: 12px;
      border-radius: var(--radius);
      background: #409eff;
    }

    .output-result-pane {
      display: flex;
      min-height: 0;
    }

    .output-result-pane .output-box {
      flex: 1 1 auto;
    }

    .output-box {
      width: 100%;
      min-height: 0;
      margin: 0;
      padding: 14px;
      overflow: auto;
      border: none;
      border-radius: var(--radius);
      background: #0f172a;
      color: #e2e8f0;
      font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
      font-size: 12px;
      line-height: 1.7;
      white-space: pre-wrap;
      word-break: break-word;
      box-shadow: inset 0 2px 6px rgba(0,0,0,0.15);
    }

    .compare-stage {
      flex: 1 1 auto;
      min-height: 0;
      position: relative;
      overflow: hidden;
      border: none;
      border-radius: var(--radius);
      background: linear-gradient(180deg, #f8fbff 0%, #eef4fa 100%);
      box-shadow: inset 0 0 0 1px #d6e0ec;
      touch-action: none;
      cursor: grab;
    }

    .compare-stage.is-dragging {
      cursor: grabbing;
    }

    .compare-stage .preview {
      width: 100%;
      height: 100%;
      min-height: 100%;
      position: relative;
      border-radius: var(--radius);
      background: transparent;
      box-shadow: inset 0 0 0 1px transparent;
      overflow: hidden;
    }

    .compare-stage .preview.has-image {
      background: #fff;
      box-shadow: inset 0 0 0 1px transparent;
    }

    .compare-stage .preview img {
      position: absolute;
      top: 50%;
      left: 50%;
      max-width: none;
      max-height: none;
      width: auto;
      height: auto;
      user-select: none;
      pointer-events: none;
      -webkit-user-drag: none;
      will-change: transform;
      backface-visibility: hidden;
    }

    .compare-empty {
      display: flex;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      width: 100%;
      margin: 0;
      color: #64748b;
      font-size: 13px;
      text-align: center;
      padding: 24px;
      border-radius: var(--radius);
      background: rgba(255, 255, 255, 0.72);
    }

    /* ─── Status Badge ─── */
    .status-badge {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      padding: 3px 10px;
      border-radius: var(--radius);
      font-size: 11px;
      font-weight: 600;
      background: #f1f5f9;
      color: var(--muted);
      box-shadow: inset 0 0 0 1px #e2e8f0;
    }

    .status-badge.connected {
      background: #d1fae5;
      color: #065f46;
      box-shadow: inset 0 0 0 1px #86efac;
    }

    .status-badge.error {
      background: #fee2e2;
      color: #991b1b;
      box-shadow: inset 0 0 0 1px #fca5a5;
    }

    .status-dot {
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: currentColor;
    }

    /* ─── Loading Spinner ─── */
    .spinner {
      width: 18px;
      height: 18px;
      border: 2px solid rgba(255,255,255,0.3);
      border-top-color: #fff;
      border-radius: 50%;
      animation: spin 0.6s linear infinite;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: scale(0.95); }
      to { opacity: 1; transform: scale(1); }
    }

    @keyframes previewReveal {
      from {
        opacity: 0;
        transform: scale(0.94);
        filter: blur(1px);
      }
      to {
        opacity: 1;
        transform: scale(1);
        filter: blur(0);
      }
    }

    @keyframes slideUp {
      from { opacity: 0; transform: translateY(8px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .fade-in {
      animation: fadeIn 0.3s ease;
    }

    .slide-up {
      animation: slideUp 0.35s ease;
    }

    /* ─── Connection Status Row ─── */
    .connection-row {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .connection-row button {
      flex-shrink: 0;
    }

    .connection-row .status-badge {
      flex-shrink: 0;
    }

    /* ─── Tooltip ─── */
    [data-tooltip] {
      position: relative;
    }

    [data-tooltip]::after {
      content: attr(data-tooltip);
      position: absolute;
      bottom: calc(100% + 6px);
      left: 50%;
      transform: translateX(-50%) translateY(4px);
      padding: 4px 8px;
      background: #1e293b;
      color: #f1f5f9;
      font-size: 11px;
      font-weight: 500;
      border-radius: var(--radius);
      white-space: nowrap;
      pointer-events: none;
      opacity: 0;
      transition: opacity 0.15s, transform 0.15s;
      z-index: 10;
    }

    [data-tooltip]:hover::after {
      opacity: 1;
      transform: translateX(-50%) translateY(0);
    }

    /* ─── Responsive ─── */
    @media (max-width: 1080px) {
      body {
        overflow: auto;
      }

      .app {
        grid-template-columns: 1fr;
        height: auto;
        flex: 0 0 auto;
      }

      .main, .sidebar {
        overflow: visible;
      }

      .output-split {
        grid-template-columns: 1fr;
      }

      .output-pane {
        min-height: 260px;
      }

      .output-section {
        max-height: none;
        min-height: 180px;
      }
    }

    /* ─── Scrollbar ─── */
    ::-webkit-scrollbar {
      width: 6px;
      height: 6px;
    }

    ::-webkit-scrollbar-track {
      background: transparent;
    }

    ::-webkit-scrollbar-thumb {
      background: #cbd5e1;
      border-radius: var(--radius);
    }

    ::-webkit-scrollbar-thumb:hover {
      background: #94a3b8;
    }

    /* ─── Processing overlay on button ─── */
    .btn-processing {
      pointer-events: none;
      position: relative;
    }

    .btn-processing::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(255,255,255,0.15);
      border-radius: inherit;
    }