/* --- Inspector (Side Panel) --- */
    .inspector {
      position: absolute;
      top: 0;
      right: 0;
      bottom: 0;
      width: 320px;
      max-width: min(360px, 92vw);
      background-color: var(--bg-panel);
      border-left: 1px solid var(--border);
      overflow-y: auto;
      display: block;
      z-index: 18;
      box-shadow: -18px 0 34px rgba(0,0,0,0.32);
      transform: translateX(100%);
      opacity: 0;
      pointer-events: none;
      transition: transform 0.18s ease, opacity 0.18s ease;
    }

    .workbench.panel-open .inspector {
      transform: translateX(0);
      opacity: 1;
      pointer-events: auto;
    }

    .workbench.panel-open .side-toggle {
      right: 336px;
    }

    @media (max-width: 720px) {
      .inspector { width: min(320px, calc(100% - 16px)); }
      .workbench.panel-open .side-toggle { right: 16px; }
    }

    .panel {
      border-bottom: 1px solid var(--border);
      background-color: var(--bg-panel);
    }

    .panel-header {
      padding: 10px 14px;
      font-weight: 600;
      font-size: 12px;
      color: var(--text-bright);
      background-color: var(--bg-surface);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .panel-header:hover { background-color: var(--bg-surface-hover); }
    
    .panel-header::before {
      content: '▼';
      font-size: 10px;
      margin-right: 6px;
      color: var(--text-muted);
    }
    
    .panel.collapsed .panel-header::before { content: '▶'; }
    .panel.collapsed .panel-body { display: none; }

    .panel-header span {
      font-weight: normal;
      color: var(--text-muted);
      text-transform: none;
    }

    .panel-body { padding: 14px; }

    /* Form Fields in Panels */
    .form-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
    }

    .field {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .field.full { grid-column: 1 / -1; }

    .field label {
      font-size: 11px;
      color: var(--text-muted);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .field input,
    .field select,
    .field textarea {
      width: 100%;
      background-color: var(--bg-base);
      border: 1px solid var(--border);
      color: var(--text-bright);
      padding: 6px 10px;
      border-radius: var(--radius-sm);
      outline: none;
    }

    .field input:focus,
    .field select:focus,
    .field textarea:focus {
      border-color: var(--border-focus);
    }

    .field input[type="color"] {
      padding: 2px 4px;
      height: 28px;
      cursor: pointer;
    }

    .check-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
    }

    .check-pill {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 12px;
      cursor: pointer;
      color: var(--text-main);
    }
    
    .check-pill input {
      accent-color: var(--accent);
      cursor: pointer;
      width: 14px;
      height: 14px;
    }

    .small-actions {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin-top: 14px;
    }

    .icon-btn {
      background-color: var(--bg-surface);
      border: 1px solid var(--border);
      color: var(--text-main);
      padding: 6px 12px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-size: 12px;
    }

    .icon-btn:hover {
      background-color: var(--bg-surface-hover);
      color: var(--text-bright);
    }

    .icon-btn.danger {
      border-color: var(--danger);
      color: #ffb3b3;
    }
    .icon-btn.danger:hover {
      background-color: var(--danger);
      color: #fff;
    }

    .icon-btn.primary-action {
      background-color: var(--accent);
      border-color: var(--border-focus);
      color: white;
    }
    .icon-btn.primary-action:hover {
      background-color: var(--accent-hover);
    }

    /* Lists */
    .entity-list,
    .layer-list,
    .cmd-log {
      display: flex;
      flex-direction: column;
      gap: 6px;
      max-height: 200px;
      overflow-y: auto;
    }

    .row-item {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 6px 10px;
      background-color: var(--bg-base);
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-size: 12px;
    }

    .row-item:hover { background-color: var(--bg-surface); }
    .row-item.active {
      border-color: var(--border-focus);
      background-color: var(--accent-active-bg);
    }

    .row-item .dot {
      width: 12px;
      height: 12px;
      border-radius: 50%;
      border: 1px solid rgba(255,255,255,0.2);
    }

    .row-item small {
      margin-left: auto;
      color: var(--text-muted);
      font-family: var(--font-mono);
      font-size: 11px;
    }

    .empty, .text-help {
      padding: 12px;
      border: 1px dashed var(--border-light);
      border-radius: var(--radius-sm);
      color: var(--text-muted);
      font-size: 12px;
      line-height: 1.5;
      text-align: center;
      background-color: rgba(255,255,255,0.02);
    }

    

/* turkcad-start-screen-css */
.tc-start-shell {
      position: fixed;
      inset: 0;
      z-index: 950;
      display: grid;
      grid-template-columns: minmax(312px, 392px) minmax(0, 1fr);
      min-width: 0;
      min-height: 0;
      background:
        radial-gradient(circle at 16% 18%, rgba(201, 42, 69, 0.18), transparent 28%),
        radial-gradient(circle at 84% 14%, rgba(255, 255, 255, 0.055), transparent 26%),
        linear-gradient(135deg, #141416 0%, #1d1d20 46%, #161618 100%);
      color: var(--text-main, #cccccc);
      font-family: var(--font-ui, "Segoe UI", "Roboto", sans-serif);
      overflow: hidden;
      isolation: isolate;
    }

    .tc-start-shell[hidden] { display: none !important; }

    .tc-start-shell::before,
    .tc-start-shell::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      z-index: 0;
    }

    .tc-start-shell::before {
      background-image:
        linear-gradient(rgba(255,255,255,0.026) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.022) 1px, transparent 1px);
      background-size: 44px 44px;
      mask-image: linear-gradient(90deg, rgba(0,0,0,0.8), rgba(0,0,0,0.18));
    }

    .tc-start-shell::after {
      background:
        linear-gradient(90deg, rgba(255,255,255,0.045), transparent 17%),
        linear-gradient(180deg, rgba(255,255,255,0.035), transparent 28%);
      mix-blend-mode: screen;
      opacity: 0.5;
    }

    .tc-start-sidebar,
    .tc-start-main {
      position: relative;
      z-index: 1;
      min-width: 0;
    }

    .tc-start-sidebar {
      display: flex;
      flex-direction: column;
      padding: 32px 28px 24px;
      border-right: 1px solid rgba(255,255,255,0.085);
      background:
        linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.018) 34%, rgba(0,0,0,0.20)),
        rgba(28, 28, 30, 0.90);
      box-shadow: 22px 0 52px rgba(0,0,0,0.31), inset -1px 0 0 rgba(0,0,0,0.38);
      backdrop-filter: blur(16px);
    }

    .tc-start-brand {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 14px;
      text-align: center;
      padding: 8px 2px 32px;
      border-bottom: 1px solid rgba(255,255,255,0.075);
    }

    .tc-start-logo {
      width: 132px;
      height: 104px;
      flex: 0 0 auto;
      display: grid;
      place-items: center;
      padding: 12px;
      border-radius: 28px;
      color: #c92a45;
      background:
        radial-gradient(circle at 50% 16%, rgba(201,42,69,0.18), transparent 52%),
        linear-gradient(145deg, rgba(255,255,255,0.085), rgba(255,255,255,0.018)),
        #19191b;
      border: 1px solid rgba(255,255,255,0.12);
      box-shadow:
        0 22px 42px rgba(0,0,0,0.38),
        0 0 0 1px rgba(201,42,69,0.10),
        inset 0 1px 0 rgba(255,255,255,0.09);
      overflow: hidden;
    }

    .tc-start-logo .tc20-user-logo,
    .tc-start-logo .tc-start-logo-svg {
      width: 100%;
      height: 100%;
      display: block;
      color: currentColor;
      filter: drop-shadow(0 12px 20px rgba(201,42,69,0.24));
    }

    .tc-start-title {
      display: flex;
      align-items: baseline;
      justify-content: center;
      gap: 0;
      margin: 0;
      color: #fff;
      font-family: var(--font-jetbrains, var(--font-mono, monospace));
      font-size: 36px;
      font-weight: 780;
      letter-spacing: -0.06em;
      line-height: 0.95;
    }

    .tc-start-title span:last-child { color: var(--accent-hover, #c92a45); }

    .tc-start-version {
      margin: 10px 0 0;
      color: #85858d;
      font-family: var(--font-jetbrains, var(--font-mono, monospace));
      font-size: 11px;
      letter-spacing: 0.22em;
      text-transform: uppercase;
    }

    .tc-start-actions {
      display: grid;
      gap: 11px;
      margin-top: 24px;
    }

    .tc-start-btn,
    .tc-start-github {
      width: 100%;
      min-height: 46px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      border-radius: 14px;
      border: 1px solid rgba(255,255,255,0.10);
      background: linear-gradient(180deg, rgba(255,255,255,0.055), rgba(255,255,255,0.015)), #242426;
      color: var(--text-bright, #ffffff);
      font-weight: 720;
      letter-spacing: 0.005em;
      cursor: pointer;
      transition: background-color 0.16s ease, border-color 0.16s ease, transform 0.12s ease, box-shadow 0.16s ease;
      text-decoration: none;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.045);
    }

    .tc-start-btn:hover,
    .tc-start-github:hover {
      transform: translateY(-1px);
      background: linear-gradient(180deg, rgba(255,255,255,0.075), rgba(255,255,255,0.025)), #303033;
      border-color: rgba(255,255,255,0.18);
      box-shadow: 0 12px 24px rgba(0,0,0,0.24), inset 0 1px 0 rgba(255,255,255,0.06);
    }

    .tc-start-btn:focus-visible,
    .tc-start-github:focus-visible,
    .tc-start-select select:focus-visible,
    .tc-release-close:focus-visible {
      outline: 2px solid var(--accent-hover, #c92a45);
      outline-offset: 2px;
    }

    .tc-start-btn::before {
      content: "";
      width: 17px;
      height: 17px;
      flex: 0 0 auto;
      background: currentColor;
      opacity: 0.92;
      mask: var(--tc-start-btn-icon) center / contain no-repeat;
      -webkit-mask: var(--tc-start-btn-icon) center / contain no-repeat;
    }

    #tcStartNewBtn { --tc-start-btn-icon: url("../assets/icons/start/new.svg"); }
    #tcStartOpenBtn { --tc-start-btn-icon: url("../assets/icons/start/open.svg"); }

    .tc-start-btn-primary {
      border-color: rgba(201,42,69,0.68);
      background: linear-gradient(180deg, var(--accent-hover, #c92a45), var(--accent, #9f1d35));
      box-shadow: 0 14px 30px rgba(159,29,53,0.30), inset 0 1px 0 rgba(255,255,255,0.14);
    }

    .tc-start-btn-primary:hover {
      border-color: rgba(255,255,255,0.20);
      background: linear-gradient(180deg, #d83452, var(--accent, #9f1d35));
      box-shadow: 0 18px 36px rgba(159,29,53,0.34), inset 0 1px 0 rgba(255,255,255,0.16);
    }

    .tc-start-spacer { flex: 1 1 auto; }

    .tc-start-controls {
      display: grid;
      gap: 10px;
      padding-top: 18px;
      border-top: 1px solid rgba(255,255,255,0.075);
    }

    .tc-start-select {
      min-height: 62px;
      display: grid;
      grid-template-columns: minmax(0, 1fr) minmax(132px, 148px);
      align-items: center;
      gap: 14px;
      padding: 12px 12px 12px 18px;
      border: 1px solid rgba(255,255,255,0.13);
      border-radius: 16px;
      background: linear-gradient(180deg, rgba(255,255,255,0.045), rgba(255,255,255,0.016)), #1f1f21;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.045), 0 10px 22px rgba(0,0,0,0.13);
    }

    .tc-start-select label {
      margin: 0;
      color: #ededf0;
      font-size: 16px;
      font-weight: 720;
      letter-spacing: -0.01em;
      text-transform: none;
    }

    .tc-start-select select {
      width: 100%;
      height: 36px;
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: 9px;
      background: #18181a;
      color: var(--text-bright, #fff);
      padding: 0 10px;
      outline: none;
      cursor: pointer;
      font-size: 14px;
      font-weight: 650;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.035);
    }

    .tc-start-github {
      min-height: 62px;
      margin-top: 2px;
      justify-content: flex-start;
      padding: 0 18px;
      color: #f4f4f5;
      background: linear-gradient(180deg, rgba(255,255,255,0.045), rgba(255,255,255,0.015)), #1f1f21;
      border-color: rgba(255,255,255,0.13);
    }

    .tc-start-github::before {
      content: "";
      width: 30px;
      height: 30px;
      flex: 0 0 auto;
      background: currentColor;
      mask: url("../assets/icons/start/github.svg") center / contain no-repeat;
      -webkit-mask: url("../assets/icons/start/github.svg") center / contain no-repeat;
    }

    .tc-start-github-main {
      display: block;
      font-size: 17px;
      font-weight: 820;
      line-height: 1.05;
    }

    .tc-start-github-sub {
      display: block;
      margin-top: 4px;
      color: #8d8d96;
      font-size: 11px;
      font-weight: 650;
      letter-spacing: 0.035em;
      text-transform: uppercase;
    }

    .tc-start-main {
      display: grid;
      align-content: start;
      padding: clamp(36px, 5vw, 68px) clamp(30px, 6vw, 88px);
      overflow-y: auto;
    }

    .tc-start-content { width: min(940px, 100%); }

    .tc-start-kicker {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 16px;
      color: var(--accent-hover, #c92a45);
      font-family: var(--font-jetbrains, var(--font-mono, monospace));
      font-size: 11px;
      font-weight: 760;
      letter-spacing: 0.14em;
      text-transform: uppercase;
    }

    .tc-start-kicker::before {
      content: "";
      width: 8px;
      height: 8px;
      border-radius: 999px;
      background: var(--accent-hover, #c92a45);
      box-shadow: 0 0 0 5px rgba(201,42,69,0.11);
    }

    .tc-start-heading {
      margin: 0 0 18px;
      color: var(--text-bright, #fff);
      font-size: clamp(32px, 4vw, 54px);
      line-height: 1.04;
      letter-spacing: -0.045em;
    }

    .tc-start-lead {
      max-width: 880px;
      margin: 0;
      color: #cccccc;
      font-size: 15px;
      line-height: 1.74;
      user-select: text;
    }

    .tc-start-lead strong { color: #ffffff; font-weight: 760; }

    .tc-start-divider {
      height: 1px;
      width: 100%;
      margin: 30px 0 24px;
      background: linear-gradient(90deg, rgba(255,255,255,0.20), rgba(255,255,255,0.04), transparent);
    }

    .tc-release-heading {
      margin: 0 0 14px;
      color: #f5f5f5;
      font-size: 16px;
      font-weight: 830;
      letter-spacing: 0.04em;
      text-transform: uppercase;
    }

    .tc-release-list {
      display: grid;
      gap: 10px;
      margin: 0;
      padding: 0 0 0 20px;
      color: #cfcfd2;
      line-height: 1.55;
      user-select: text;
    }

    .tc-release-list li::marker { color: var(--accent-hover, #c92a45); }

    .tc-start-release-action { margin-top: 24px; }

    .tc-start-link-btn {
      min-height: 40px;
      padding: 0 16px;
      border: 1px solid rgba(201,42,69,0.42);
      border-radius: 12px;
      background: rgba(159,29,53,0.14);
      color: #fff;
      font-weight: 760;
      cursor: pointer;
      transition: background-color 0.16s ease, border-color 0.16s ease, transform 0.12s ease;
    }

    .tc-start-link-btn:hover {
      transform: translateY(-1px);
      background: rgba(159,29,53,0.23);
      border-color: rgba(201,42,69,0.72);
    }

    .tc-release-backdrop {
      position: fixed;
      inset: 0;
      z-index: 980;
      display: none;
      place-items: center;
      padding: 28px;
      background: rgba(0,0,0,0.52);
      backdrop-filter: blur(9px);
    }

    .tc-release-backdrop.show { display: grid; }

    .tc-release-modal {
      width: min(900px, 94vw);
      max-height: min(820px, 88vh);
      display: grid;
      grid-template-rows: auto minmax(0, 1fr);
      background: linear-gradient(180deg, #222225, #171719);
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: 20px;
      box-shadow: 0 26px 80px rgba(0,0,0,0.48), 0 0 0 1px rgba(159,29,53,0.13);
      overflow: hidden;
    }

    .tc-release-modal-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      padding: 18px 20px;
      border-bottom: 1px solid rgba(255,255,255,0.085);
      background: rgba(255,255,255,0.035);
    }

    .tc-release-modal-title { margin: 0; color: #fff; font-size: 18px; font-weight: 830; letter-spacing: 0.02em; }

    .tc-release-close {
      width: 36px;
      height: 36px;
      display: grid;
      place-items: center;
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: 11px;
      background: rgba(255,255,255,0.045);
      color: #fff;
      cursor: pointer;
      font-size: 22px;
      line-height: 1;
    }

    .tc-release-close:hover { background: rgba(201,42,69,0.20); }
    .tc-release-modal-body { overflow-y: auto; padding: 20px; }

    .tc-release-card {
      padding: 17px 18px 15px;
      border: 1px solid rgba(255,255,255,0.09);
      border-radius: 16px;
      background: linear-gradient(180deg, rgba(255,255,255,0.045), rgba(255,255,255,0.022));
    }

    .tc-release-card + .tc-release-card { margin-top: 12px; }
    .tc-release-card h3 { margin: 0 0 11px; color: #fff; font-size: 14px; font-weight: 830; letter-spacing: 0.055em; text-transform: uppercase; }
    .tc-release-card ul { display: grid; gap: 8px; margin: 0; padding-left: 18px; color: #cdcdcf; line-height: 1.52; }
    .tc-release-card li::marker { color: var(--accent-hover, #c92a45); }

    body.ui-light .tc-start-shell {
      background:
        radial-gradient(circle at 16% 18%, rgba(201, 42, 69, 0.13), transparent 28%),
        radial-gradient(circle at 84% 14%, rgba(17,24,39,0.055), transparent 26%),
        linear-gradient(135deg, #f3f5f8 0%, #e8ecf2 52%, #dce2ea 100%);
      color: #263241;
    }

    body.ui-light .tc-start-sidebar { background: rgba(255,255,255,0.78); border-right-color: rgba(17,24,39,0.10); }
    body.ui-light .tc-start-logo { background: linear-gradient(145deg, #ffffff, #eef2f7); border-color: #d2d8e1; box-shadow: 0 14px 26px rgba(17,24,39,.14); }
    body.ui-light .tc-start-title span:first-child, body.ui-light .tc-start-heading, body.ui-light .tc-release-heading { color: #111827; }
    body.ui-light .tc-start-lead, body.ui-light .tc-release-list { color: #364152; }
    body.ui-light .tc-start-lead strong { color: #111827; }
    body.ui-light .tc-start-select { background: rgba(255,255,255,0.72); border-color: rgba(17,24,39,0.12); }
    body.ui-light .tc-start-select label { color: #111827; }
    body.ui-light .tc-start-select select { background: #ffffff; color: #111827; border-color: #cfd4dc; }
    body.ui-light .tc-start-github, body.ui-light .tc-start-btn:not(.tc-start-btn-primary) { background: rgba(255,255,255,0.72); color: #111827; border-color: rgba(17,24,39,0.12); }
    body.ui-light .tc-start-github-sub { color: #667085; }
    body.ui-light .tc-release-modal { background: linear-gradient(180deg, #ffffff, #f2f4f7); border-color: rgba(17,24,39,0.12); }
    body.ui-light .tc-release-modal-title, body.ui-light .tc-release-card h3 { color: #111827; }
    body.ui-light .tc-release-close { color: #111827; background: #fff; border-color: #cfd4dc; }
    body.ui-light .tc-release-card { background: rgba(17,24,39,0.035); border-color: rgba(17,24,39,0.08); }
    body.ui-light .tc-release-card ul { color: #364152; }

    @media (max-width: 900px) {
      .tc-start-shell { grid-template-columns: 1fr; overflow-y: auto; }
      .tc-start-sidebar { min-height: auto; padding: 18px; border-right: 0; border-bottom: 1px solid rgba(255,255,255,0.08); }
      .tc-start-brand { padding-bottom: 18px; }
      .tc-start-logo { width: 104px; height: 82px; border-radius: 22px; padding: 10px; }
      .tc-start-title { font-size: 30px; }
      .tc-start-actions { grid-template-columns: 1fr 1fr; margin-top: 16px; }
      .tc-start-spacer { display: none; }
      .tc-start-controls { grid-template-columns: 1fr 1fr; padding-top: 14px; margin-top: 14px; }
      .tc-start-github { margin-top: 0; grid-column: 1 / -1; }
      .tc-start-main { padding: 28px 20px 36px; }
    }

    @media (max-width: 600px) {
      .tc-start-actions, .tc-start-controls { grid-template-columns: 1fr; }
      .tc-start-select { grid-template-columns: 1fr; gap: 8px; }
      .tc-start-heading { font-size: 30px; }
      .tc-start-lead { font-size: 14px; }
    }

/* turkcad-final-start-polish-css */
/* =========================================================
       TurkCAD Start Screen final polish — visual heading, help,
       About actions and modal stacking
       ========================================================= */
    .tc-start-heading-brand {
      max-width: 980px;
      color: var(--text-bright, #fff);
    }

    .tc-heading-word {
      display: inline-block;
      font-family: var(--font-jetbrains, var(--font-mono, monospace));
      font-weight: 900;
      letter-spacing: -0.075em;
      margin-right: 0.035em;
    }

    .tc-heading-turk {
      color: #ffffff;
    }

    .tc-heading-cad {
      color: var(--accent-hover, #c92a45);
      text-shadow: 0 0 24px rgba(201, 42, 69, 0.20);
    }

    .tc-heading-rest {
      color: var(--text-bright, #ffffff);
      letter-spacing: -0.045em;
    }

    #tcStartHelpBtn {
      --tc-start-btn-icon: url("../assets/icons/start/help.svg");
    }

    body.tc-start-visible #modalBackdrop.show {
      z-index: 995;
      background-color: rgba(0, 0, 0, 0.56);
      backdrop-filter: blur(9px);
    }

    body.tc-start-visible #modalBackdrop .modal {
      border-radius: 20px;
      border-color: rgba(255,255,255,0.13);
      box-shadow: 0 26px 80px rgba(0,0,0,0.50), 0 0 0 1px rgba(159,29,53,0.13);
    }
    body.tc-start-visible #modalBackdrop,
    body.tc-start-visible #modalBackdrop.show {
      z-index: 1250 !important;
    }

    body.tc-start-visible #modalBackdrop .modal {
      position: relative;
      z-index: 1251;
    }


    .tc-help-clean-hero {
      display: grid;
      grid-template-columns: 72px minmax(0, 1fr);
      gap: 16px;
      align-items: center;
      padding: 16px;
      border: 1px solid var(--border);
      border-radius: 16px;
      background:
        radial-gradient(circle at 16% 16%, rgba(201,42,69,0.18), transparent 44%),
        linear-gradient(135deg, rgba(159,29,53,0.22), rgba(255,255,255,0.035));
      margin-bottom: 14px;
    }

    .tc-help-clean-hero .tc20-guide-logo {
      width: 72px;
      height: 58px;
      display: grid;
      place-items: center;
      color: var(--accent-hover, #c92a45);
      border-radius: 16px;
      background: rgba(0,0,0,0.18);
      border: 1px solid rgba(255,255,255,0.08);
      padding: 8px;
    }

    .tc-help-clean-hero .tc20-user-logo {
      width: 100%;
      height: 100%;
      display: block;
    }

    .tc-help-clean-hero h3 {
      margin: 0 0 6px;
      color: var(--text-bright);
      font-size: 19px;
      letter-spacing: -0.02em;
    }

    .tc-help-clean-hero p {
      margin: 0;
      color: var(--text-main);
      line-height: 1.5;
    }

    .tc-help-clean-body {
      display: grid;
      gap: 10px;
      color: var(--text-main);
      line-height: 1.6;
    }

    .tc-help-clean-note {
      padding: 12px 14px;
      border-left: 3px solid var(--accent-hover, #c92a45);
      border-radius: 12px;
      background: rgba(255,255,255,0.035);
    }

    .tc-help-clean-note b {
      color: var(--text-bright);
    }

    .tc20-about-actions {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 10px;
      margin-top: 12px;
    }

    .tc20-about-action {
      min-height: 42px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 0 14px;
      border-radius: 12px;
      border: 1px solid rgba(201,42,69,0.42);
      background: rgba(159,29,53,0.14);
      color: var(--text-bright, #fff);
      text-decoration: none;
      font-weight: 760;
      cursor: pointer;
      transition: transform 0.12s ease, background-color 0.16s ease, border-color 0.16s ease;
    }

    .tc20-about-action:hover {
      transform: translateY(-1px);
      background: rgba(159,29,53,0.23);
      border-color: rgba(201,42,69,0.72);
    }

    .tc20-about-action.secondary {
      border-color: rgba(255,255,255,0.12);
      background: rgba(255,255,255,0.045);
    }

    .tc20-about-action.secondary:hover {
      border-color: rgba(255,255,255,0.20);
      background: rgba(255,255,255,0.075);
    }

    .tc20-about-card > p {
      margin: 0;
      padding: 13px 14px 0;
      color: var(--text-main);
      line-height: 1.55;
    }

    .tc20-about-actions {
      padding: 0 14px 14px;
      box-sizing: border-box;
    }

    .tc20-about-action {
      min-width: 0;
      box-sizing: border-box;
      text-align: center;
      line-height: 1.2;
      white-space: normal;
      overflow-wrap: break-word;
    }

    body.ui-light .tc-heading-turk,
    body.ui-light .tc-heading-rest {
      color: #1f2933;
    }

    body.ui-light .tc-heading-cad {
      color: var(--accent, #9f1d35);
      text-shadow: none;
    }

    body.ui-light .tc-help-clean-hero {
      background:
        radial-gradient(circle at 16% 16%, rgba(201,42,69,0.12), transparent 44%),
        linear-gradient(135deg, rgba(159,29,53,0.11), rgba(17,24,39,0.035));
    }

    body.ui-light .tc-help-clean-hero .tc20-guide-logo {
      background: rgba(255,255,255,0.72);
      border-color: rgba(17,24,39,0.10);
    }

    body.ui-light .tc-help-clean-note {
      background: rgba(17,24,39,0.035);
    }

    body.ui-light .tc20-about-action {
      color: #111827;
      background: rgba(159,29,53,0.10);
    }

    body.ui-light .tc20-about-action.secondary {
      background: rgba(255,255,255,0.72);
      border-color: rgba(17,24,39,0.12);
    }

    @media (max-width: 600px) {
      .tc-help-clean-hero {
        grid-template-columns: 1fr;
      }

      .tc20-about-actions {
        grid-template-columns: 1fr;
      }
    }

    .tc37-prop-section {
      border-top: 1px solid var(--border);
      padding-top: 10px;
      margin-top: 12px;
    }

    .tc37-prop-section:first-child {
      border-top: 0;
      padding-top: 0;
      margin-top: 0;
    }

    .tc37-prop-section h4 {
      margin: 0 0 10px;
      font-size: 11px;
      font-weight: 700;
      color: var(--text-bright);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .tc37-style-grid {
      grid-column: 1 / -1;
      display: grid;
      margin-top: 10px;
      border: 1px solid rgba(255,255,255,0.10);
      border-radius: var(--radius-sm);
      overflow: hidden;
      background: linear-gradient(180deg, rgba(255,255,255,0.045), rgba(255,255,255,0.018)), var(--bg-base);
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.04);
    }

    .tc37-style-row {
      display: grid;
      grid-template-columns: 44px minmax(0, 1fr) minmax(72px, 0.86fr);
      gap: 8px;
      align-items: center;
      min-width: 0;
      min-height: 34px;
      padding: 5px 8px;
      border-top: 1px solid var(--border);
    }

    .tc37-style-row:first-child { border-top: 0; }

    .tc37-style-row label {
      color: var(--text-muted);
      font-size: 10px;
      font-weight: 700;
      letter-spacing: 0.35px;
      text-transform: uppercase;
    }

    .tc37-style-row select,
    .tc37-style-row input {
      min-width: 0;
      height: 26px;
      background: rgba(255,255,255,0.035);
      border: 1px solid transparent;
      color: var(--text-main);
      border-radius: var(--radius-sm);
      padding: 3px 6px;
      font-size: 11px;
    }

    .tc37-style-row select:focus,
    .tc37-style-row input:focus {
      border-color: var(--border-focus);
      background: var(--bg-surface);
    }

    .tc37-style-row input[type="color"] {
      width: 100%;
      padding: 2px 4px;
    }

    .tc37-style-preview {
      width: 36px;
      height: 22px;
      display: grid;
      place-items: center;
      color: var(--text-main);
      border-radius: 3px;
      background: rgba(255,255,255,0.04);
      border: 1px solid rgba(255,255,255,0.08);
      overflow: hidden;
    }

    .tc37-color-preview {
      grid-template-columns: repeat(4, 1fr);
      gap: 1px;
      padding: 2px;
    }

    .tc37-color-preview::before,
    .tc37-color-preview::after,
    .tc37-color-preview i {
      content: "";
      display: block;
      width: 100%;
      height: 100%;
      min-height: 16px;
    }

    .tc37-color-preview::before { background: #f59e0b; }
    .tc37-color-preview::after { background: #22d3ee; }

    .tc37-linetype-preview::before {
      content: "";
      width: 30px;
      height: 0;
      border-top: 2px dashed currentColor;
    }

    .tc37-lineweight-preview::before {
      content: "";
      width: 30px;
      height: 3px;
      background: currentColor;
      border-radius: 999px;
    }

    .tc37-scale-preview {
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 800;
      letter-spacing: 0;
    }

    .tc37-resolved {
      grid-column: 2 / -1;
      color: var(--text-muted);
      font-size: 10px;
      line-height: 1.2;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    .tc37-style-caption {
      padding: 4px 8px 5px;
      color: var(--text-muted);
      background: rgba(0,0,0,0.10);
      border-top: 1px solid var(--border);
      font-size: 10px;
      font-weight: 700;
      letter-spacing: 0.08em;
      text-align: center;
      text-transform: uppercase;
    }

    .tc37-layer-style-editor {
      margin-top: 0;
    }

    .tc37-layer-table {
      display: grid;
      gap: 6px;
      min-width: 0;
    }

    .tc37-layer-head,
    .tc37-layer-row {
      display: grid;
      grid-template-columns: minmax(0, 1fr) 42px;
      gap: 6px;
      align-items: center;
      min-width: 0;
    }

    .tc37-layer-head {
      display: none;
      color: var(--text-muted);
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.4px;
      padding: 0 4px 4px;
    }

    .tc37-layer-row {
      padding: 5px;
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      background: var(--bg-base);
      grid-template-columns: minmax(0, 1fr) 42px;
    }

    .tc37-layer-row.active {
      border-color: var(--accent);
      background: rgba(159, 29, 53, 0.14);
    }

    .tc37-layer-name {
      display: flex;
      align-items: center;
      gap: 7px;
      min-width: 0;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      color: var(--text-bright);
      font-size: 12px;
      grid-column: 1 / 2;
    }

    .tc37-layer-style {
      grid-column: 1 / -1;
      color: var(--text-muted);
      font-size: 10px;
      line-height: 1.25;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
      padding-left: 17px;
    }

    .tc37-layer-name i {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      flex: 0 0 auto;
      border: 1px solid rgba(255, 255, 255, 0.35);
    }

    .tc37-layer-row input[type="color"] {
      width: 36px;
      height: 24px;
      padding: 2px;
      grid-column: 2 / 3;
    }

    .tc37-layer-row select,
    .tc37-layer-row input[type="number"] {
      min-width: 0;
      width: 100%;
      background: var(--bg-surface);
      border: 1px solid var(--border);
      color: var(--text-main);
      border-radius: var(--radius-sm);
      font-size: 11px;
      padding: 3px 5px;
    }

    .tc37-layer-row select,
    .tc37-layer-row input[type="number"],
    .tc37-layer-actions {
      grid-column: 1 / -1;
    }

    .tc37-layer-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 5px;
    }

    .tc37-layer-actions .layer-mini-btn {
      min-width: 28px;
      width: 28px;
      min-height: 26px;
      height: 26px;
      padding: 0;
      display: inline-grid;
      place-items: center;
      font-size: 0;
      position: relative;
      border-radius: 5px;
      color: var(--text-main);
      background: rgba(255,255,255,0.035);
      overflow: hidden;
    }

    .tc37-layer-actions .layer-mini-btn:hover {
      color: var(--text-bright);
      border-color: var(--border-focus);
      background: rgba(255,255,255,0.07);
    }

    .tc37-icon-btn span { display: none; }

    .tc37-icon-btn::before {
      content: "";
      display: block;
      width: 13px;
      height: 13px;
      box-sizing: border-box;
      color: currentColor;
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
    }

    .tc37-icon-btn[data-layer-action="visibility"]::before {
      width: 15px;
      height: 10px;
      border: 1.5px solid currentColor;
      border-radius: 50%;
      background: radial-gradient(circle at center, currentColor 0 2px, transparent 2.5px);
    }

    .tc37-icon-btn[data-layer-action="visibility"].is-off::after,
    .tc37-icon-btn[data-layer-action="printable"].is-off::after {
      content: "";
      position: absolute;
      width: 18px;
      height: 1.5px;
      background: currentColor;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%) rotate(-38deg);
      border-radius: 999px;
    }

    .tc37-icon-btn[data-layer-action="lock"]::before {
      width: 12px;
      height: 10px;
      border: 1.5px solid currentColor;
      border-radius: 2px;
      top: 58%;
    }

    .tc37-icon-btn[data-layer-action="lock"]::after {
      content: "";
      position: absolute;
      width: 9px;
      height: 8px;
      border: 1.5px solid currentColor;
      border-bottom: 0;
      border-radius: 8px 8px 0 0;
      left: 50%;
      top: 39%;
      transform: translate(-50%, -50%);
    }

    .tc37-icon-btn[data-layer-action="lock"].is-unlocked::after {
      left: 56%;
      transform: translate(-50%, -50%) rotate(18deg);
      border-left-color: transparent;
    }

    .tc37-icon-btn[data-layer-action="printable"]::before {
      width: 14px;
      height: 11px;
      border: 1.5px solid currentColor;
      border-radius: 2px;
      box-shadow: inset 0 4px 0 rgba(255,255,255,0.08);
    }

    .tc37-icon-btn[data-layer-action="edit"]::before {
      width: 14px;
      height: 3px;
      background: currentColor;
      border-radius: 2px;
      transform: translate(-50%, -50%) rotate(-35deg);
      box-shadow: 5px 0 0 -1px currentColor;
    }

    .tc37-icon-btn[data-layer-action="delete"]::before {
      width: 11px;
      height: 12px;
      border: 1.5px solid currentColor;
      border-top: 0;
      border-radius: 0 0 2px 2px;
      box-shadow: 0 -4px 0 -1px currentColor;
    }

    .tc37-icon-btn.disabled-look {
      opacity: 0.45;
      cursor: not-allowed;
    }

    .tc37-icon-btn.is-off,
    .tc37-icon-btn.is-locked {
      color: var(--accent-hover);
      background: rgba(159, 29, 53, 0.12);
      border-color: rgba(159, 29, 53, 0.36);
    }

    body.ui-light .tc37-style-grid {
      background: linear-gradient(180deg, rgba(17,24,39,0.025), rgba(17,24,39,0.010)), #ffffff;
      border-color: rgba(17,24,39,0.10);
    }

    body.ui-light .tc37-style-preview,
    body.ui-light .tc37-layer-actions .layer-mini-btn {
      background: rgba(17,24,39,0.035);
      border-color: rgba(17,24,39,0.08);
    }

    /* Layer action icons use real SVG masks for a sharper, more readable panel. */
    .tc37-layer-actions .tc37-icon-btn::before {
      width: 16px;
      height: 16px;
      border: 0;
      border-radius: 0;
      box-shadow: none;
      background: currentColor;
      -webkit-mask: var(--tc37-layer-icon) center / contain no-repeat;
      mask: var(--tc37-layer-icon) center / contain no-repeat;
      transform: translate(-50%, -50%);
    }

    .tc37-layer-actions .tc37-icon-btn::after {
      content: none !important;
    }

    .tc37-icon-btn[data-layer-action="visibility"] {
      --tc37-layer-icon: url("../assets/icons/layers/eye.svg");
    }

    .tc37-icon-btn[data-layer-action="visibility"].is-off {
      --tc37-layer-icon: url("../assets/icons/layers/eye-off.svg");
    }

    .tc37-icon-btn[data-layer-action="lock"] {
      --tc37-layer-icon: url("../assets/icons/layers/lock.svg");
    }

    .tc37-icon-btn[data-layer-action="lock"].is-unlocked {
      --tc37-layer-icon: url("../assets/icons/layers/unlock.svg");
    }

    .tc37-layer-actions .tc37-icon-btn[data-layer-action="lock"]::before {
      width: 15px;
      height: 15px;
      top: calc(50% + 0.5px);
    }

    .tc37-icon-btn[data-layer-action="printable"] {
      --tc37-layer-icon: url("../assets/icons/layers/printer.svg");
    }

    .tc37-icon-btn[data-layer-action="printable"].is-off {
      --tc37-layer-icon: url("../assets/icons/layers/printer-off.svg");
    }

    .tc37-icon-btn[data-layer-action="edit"] {
      --tc37-layer-icon: url("../assets/icons/layers/pencil.svg");
    }

    .tc37-icon-btn[data-layer-action="delete"] {
      --tc37-layer-icon: url("../assets/icons/layers/trash.svg");
    }