/* ==========================================================================
       1. VARIABLES CSS — SISTEMA DE DISEÑO "ZENITH MONOCHROME" (DESIGN.md)
       ========================================================================== */
    :root {
      /* Tipografías */
      --font-display: ui-monospace, 'Cascadia Code', Consolas, 'Courier New', monospace;
      --font-headline: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
      --font-body: system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
      --font-mono: ui-monospace, 'Cascadia Code', Consolas, 'Courier New', monospace;

      /* Estética Recta y Formal (Sin bordes redondeados) */
      --radius-sm: 0px;
      --radius-md: 0px;
      --radius-lg: 0px;
      --radius-xl: 0px;
      --radius-full: 0px;
      --unit: 8px;
      --bento-gap: 1px;

      /* Paleta Modo Claro (Derivada de DESIGN.md) */
      --bg-canvas: #ffffff;
      --bg-app: #e2e2e4;
      --surface-bento: rgba(255, 255, 255, 0.94);
      --surface-solid: #ffffff;
      --surface-low: #f6f6f8;
      --surface-high: #ededf0;
      --surface-highest: #e2e2e4;
      --text-primary: #141516;
      --text-secondary: #4c4546;
      --text-muted: #7e7576;
      --border-subtle: rgba(0, 0, 0, 0.08);
      --border-strong: #c8c4c5;
      --primary: #000000;
      --on-primary: #ffffff;
      --accent-crimson: #ba002c;
      --accent-crimson-hover: #980023;
      --on-crimson: #ffffff;
      --accent-chrome: #2e4d32;
      --accent-chrome-bg: #c7ecc7;
      --error: #ba1a1a;
      --error-bg: #ffdad6;
      --shadow-long: 0 12px 32px rgba(0, 0, 0, 0.06);
      --ruler-bg: rgba(255, 255, 255, 0.72);
      --ruler-tick: rgba(126, 117, 118, 0.45);
      --checker-a: #f7f7f9;
      --checker-b: #f0f0f3;
    }

    [data-theme="dark"] {
      /* Paleta Modo Oscuro derivada del sistema Zenith Monochrome */
      --bg-canvas: #121315;
      --bg-app: #26282b;
      --surface-bento: rgba(20, 22, 24, 0.95);
      --surface-solid: #16181a;
      --surface-low: #1d2023;
      --surface-high: #26292d;
      --surface-highest: #31353a;
      --text-primary: #f2f2f4;
      --text-secondary: #b8b8bc;
      --text-muted: #7d7d82;
      --border-subtle: rgba(255, 255, 255, 0.08);
      --border-strong: #383b40;
      --primary: #ffffff;
      --on-primary: #111213;
      --accent-crimson: #df2842;
      --accent-crimson-hover: #ff475e;
      --on-crimson: #ffffff;
      --accent-chrome: #8ad48e;
      --accent-chrome-bg: #082e12;
      --error: #ff897d;
      --error-bg: #410002;
      --shadow-long: 0 16px 36px rgba(0, 0, 0, 0.45);
      --ruler-bg: rgba(18, 19, 21, 0.72);
      --ruler-tick: rgba(160, 160, 168, 0.38);
      --checker-a: #16181a;
      --checker-b: #121416;
    }

    /* Reset y base */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html, body {
      height: 100%;
      width: 100%;
      overflow: hidden;
      background-color: var(--bg-app);
      color: var(--text-primary);
      font-family: var(--font-body);
      font-size: 14px;
      line-height: 1.45;
      -webkit-font-smoothing: antialiased;
    }

    /* Accesibilidad de foco formal */
    :focus-visible {
      outline: 2px solid var(--accent-crimson);
      outline-offset: -2px;
    }

    button, select, input {
      font: inherit;
      color: inherit;
      border-radius: 0;
    }

    /* ==========================================================================
       2. ESTRUCTURA PRINCIPAL Y BARRA SUPERIOR ARQUITECTÓNICA (RECTA)
       ========================================================================== */
    .app-shell {
      display: flex;
      flex-direction: column;
      height: 100vh;
      height: 100dvh;
      width: 100vw;
      background: var(--border-strong);
      gap: 1px;
    }

    .top-navbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      padding: 0 18px;
      height: 52px;
      background: var(--surface-solid);
      z-index: 30;
      flex-shrink: 0;
    }

    .brand-group {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .brand-logo {
      font-family: var(--font-headline);
      font-weight: 700;
      font-size: 15px;
      letter-spacing: 0.1em;
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }

    .brand-logo .kanji {
      font-family: var(--font-display);
      font-weight: 400;
      font-size: 14px;
      color: var(--accent-crimson);
    }

    .tag-chip {
      font-family: var(--font-mono);
      font-size: 10px;
      font-weight: 600;
      letter-spacing: 0.08em;
      text-transform: uppercase;
      padding: 3px 8px;
      background: var(--surface-high);
      color: var(--text-secondary);
      border: 1px solid var(--border-subtle);
    }

    /* Pasos visibles: 1. Talla y color · 2. Sube tu diseño · 3. Descarga */
    .steps-bar {
      display: flex;
      align-items: stretch;
      height: 100%;
      overflow-x: auto;
      scrollbar-width: none;
    }
    .steps-bar::-webkit-scrollbar { display: none; }

    .step-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 0 16px;
      border: none;
      border-bottom: 2px solid transparent;
      background: transparent;
      font-family: var(--font-headline);
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 0.03em;
      text-transform: uppercase;
      color: var(--text-secondary);
      cursor: pointer;
      transition: all 0.15s ease;
      white-space: nowrap;
    }

    .step-pill:hover {
      background: var(--surface-low);
      color: var(--text-primary);
    }

    .step-pill.active {
      border-bottom-color: var(--accent-crimson);
      color: var(--text-primary);
      background: var(--surface-low);
    }

    .step-pill .step-num {
      font-family: var(--font-mono);
      font-size: 10px;
      width: 18px;
      height: 18px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      background: var(--surface-high);
      color: var(--text-primary);
    }

    .step-pill.active .step-num {
      background: var(--accent-crimson);
      color: var(--on-crimson);
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    /* ==========================================================================
       3. LAYOUT PRINCIPAL: PANEL LATERAL + MESA DE TRABAJO CON DOCK DE DISEÑO
       ========================================================================== */
    .workspace-grid {
      display: grid;
      grid-template-columns: 340px 1fr;
      gap: 1px;
      background: var(--border-strong);
      flex: 1;
      min-height: 0;
    }

    /* Panel de Controles (Izquierda en PC, Abajo con Pestañas en Móvil) */
    .controls-panel {
      background: var(--surface-solid);
      display: flex;
      flex-direction: column;
      min-height: 0;
      overflow: hidden;
    }

    /* Pestañas móviles ocultas en escritorio */
    .mobile-panel-tabs {
      display: none;
      grid-template-columns: repeat(3, 1fr);
      background: var(--surface-low);
      border-bottom: 1px solid var(--border-strong);
      flex-shrink: 0;
    }

    .mobile-tab-btn {
      min-height: 44px;
      border: none;
      border-right: 1px solid var(--border-subtle);
      border-bottom: 2px solid transparent;
      background: transparent;
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--text-secondary);
      cursor: pointer;
    }

    .mobile-tab-btn.active {
      background: var(--surface-solid);
      color: var(--text-primary);
      border-bottom-color: var(--accent-crimson);
    }

    .controls-scroll {
      overflow-y: auto;
      display: flex;
      flex-direction: column;
      flex: 1;
    }

    .bento-section {
      background: var(--surface-solid);
      border-bottom: 1px solid var(--border-strong);
      padding: 18px;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .section-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .section-title {
      font-family: var(--font-mono);
      font-size: 11px;
      font-weight: 600;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .section-step-badge {
      background: var(--primary);
      color: var(--on-primary);
      padding: 2px 6px;
      font-size: 10px;
    }

    /* ==========================================================================
       4. CONTROLES DE FORMULARIO, TALLAS Y COLORES (LÍNEAS RECTAS)
       ========================================================================== */
    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
    }

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

    .field-label {
      font-size: 11px;
      font-family: var(--font-mono);
      text-transform: uppercase;
      letter-spacing: 0.04em;
      font-weight: 500;
      color: var(--text-secondary);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .select-input, .text-input {
      min-height: 40px;
      padding: 0 10px;
      border: 1px solid var(--border-strong);
      background: var(--surface-low);
      color: var(--text-primary);
      font-weight: 500;
      font-size: 13px;
      cursor: pointer;
      transition: border-color 0.15s;
    }

    .select-input:hover, .text-input:hover {
      border-color: var(--text-primary);
    }

    .size-specs-pill {
      display: flex;
      justify-content: space-between;
      background: var(--surface-low);
      padding: 8px 12px;
      font-family: var(--font-mono);
      font-size: 11px;
      color: var(--text-secondary);
      border: 1px solid var(--border-subtle);
      border-left: 3px solid var(--primary);
    }

    /* Selector de colores cuadrados y formales */
    .swatches-grid {
      display: grid;
      grid-template-columns: repeat(8, 1fr);
      gap: 6px;
      align-items: center;
    }

    .color-swatch {
      width: 100%;
      aspect-ratio: 1 / 1;
      min-height: 32px;
      border: 1px solid var(--border-strong);
      cursor: pointer;
      position: relative;
      transition: transform 0.12s ease, border-color 0.12s ease;
    }

    .color-swatch:hover {
      border-color: var(--text-primary);
    }

    .color-swatch.active {
      outline: 2px solid var(--accent-crimson);
      outline-offset: 1px;
    }

    .color-picker-wrapper {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 4px 10px;
      border: 1px solid var(--border-strong);
      background: var(--surface-low);
      min-height: 36px;
      cursor: pointer;
    }

    .color-picker-wrapper input[type="color"] {
      width: 22px;
      height: 22px;
      border: none;
      background: none;
      cursor: pointer;
      padding: 0;
    }

    .disabled-parts-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
      padding-top: 8px;
      border-top: 1px solid var(--border-subtle);
    }

    .disabled-part-box {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 7px 10px;
      background: var(--surface-low);
      border: 1px solid var(--border-subtle);
      opacity: 0.65;
      cursor: not-allowed;
      font-size: 11px;
      font-family: var(--font-mono);
    }

    .mini-swatch-sync {
      width: 14px;
      height: 14px;
      border: 1px solid var(--border-strong);
    }

    /* ==========================================================================
       5. ZONA DE SUBIDA DE IMAGEN Y BOTONES FORMALES
       ========================================================================== */
    .dropzone {
      border: 1px dashed var(--border-strong);
      padding: 16px 12px;
      text-align: center;
      background: var(--surface-low);
      cursor: pointer;
      transition: all 0.15s ease;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 5px;
    }

    .dropzone:hover, .dropzone.dragover {
      border-color: var(--accent-crimson);
      border-style: solid;
      background: var(--surface-high);
    }

    .dropzone-title {
      font-family: var(--font-headline);
      font-weight: 600;
      font-size: 13px;
      text-transform: uppercase;
      letter-spacing: 0.04em;
    }

    .dropzone-sub {
      font-family: var(--font-mono);
      font-size: 10px;
      color: var(--text-muted);
    }

    /* Botones Rectos Formales */
    .btn {
      min-height: 42px;
      padding: 0 18px;
      font-family: var(--font-headline);
      font-weight: 600;
      font-size: 12px;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      cursor: pointer;
      transition: all 0.15s ease;
      border: 1px solid transparent;
      text-decoration: none;
      user-select: none;
    }

    .btn-primary {
      background: var(--primary);
      color: var(--on-primary);
    }

    .btn-primary:hover:not(:disabled) {
      background: var(--accent-crimson);
      color: var(--on-crimson);
    }

    .btn-crimson {
      background: var(--accent-crimson);
      color: var(--on-crimson);
    }

    .btn-crimson:hover:not(:disabled) {
      background: var(--accent-crimson-hover);
    }

    .btn-ghost {
      background: transparent;
      border-color: var(--border-strong);
      color: var(--text-primary);
    }

    .btn-ghost:hover:not(:disabled) {
      background: var(--primary);
      color: var(--on-primary);
      border-color: var(--primary);
    }

    .btn-icon {
      min-width: 38px;
      min-height: 38px;
      padding: 0 10px;
      background: var(--surface-low);
      border: 1px solid var(--border-strong);
      color: var(--text-primary);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      cursor: pointer;
      transition: all 0.12s ease;
      font-size: 11px;
      font-family: var(--font-mono);
      font-weight: 500;
    }

    .btn-icon:hover:not(:disabled) {
      background: var(--surface-high);
      border-color: var(--text-primary);
    }

    .btn-icon.active {
      background: var(--primary);
      color: var(--on-primary);
      border-color: var(--primary);
    }

    .btn-icon:disabled, .btn:disabled {
      opacity: 0.38;
      cursor: not-allowed;
    }

    /* Switch Recto para Diseño Envolvente */
    .wrap-toggle-card {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      padding: 10px 12px;
      background: var(--surface-low);
      border: 1px solid var(--border-strong);
    }

    .wrap-toggle-card.active {
      border-color: var(--accent-crimson);
      border-left: 3px solid var(--accent-crimson);
    }

    .toggle-switch {
      position: relative;
      width: 44px;
      height: 24px;
      flex-shrink: 0;
    }

    .toggle-switch input {
      opacity: 0;
      width: 0;
      height: 0;
    }

    .toggle-slider {
      position: absolute;
      cursor: pointer;
      inset: 0;
      background-color: var(--surface-highest);
      transition: 0.15s;
      border: 1px solid var(--border-strong);
    }

    .toggle-slider::before {
      position: absolute;
      content: "";
      height: 16px;
      width: 16px;
      left: 3px;
      bottom: 3px;
      background-color: var(--text-primary);
      transition: 0.15s;
    }

    .toggle-switch input:checked + .toggle-slider {
      background-color: var(--accent-crimson);
      border-color: var(--accent-crimson);
    }

    .toggle-switch input:checked + .toggle-slider::before {
      transform: translateX(20px);
      background-color: #ffffff;
    }

    /* ==========================================================================
       6. MESA DE TRABAJO Y BARRA CONTEXTUAL DE HERRAMIENTAS DE DISEÑO
       ========================================================================== */
    .stage-container {
      position: relative;
      background: var(--bg-canvas);
      display: flex;
      flex-direction: column;
      overflow: hidden;
      min-height: 0;
    }

    /* Barra superior 1: Lado de la prenda + Vistas (Deshacer, Rehacer, Cuadrícula, Cotas) */
    .stage-toolbar-top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 8px;
      padding: 6px 14px;
      background: var(--surface-solid);
      border-bottom: 1px solid var(--border-strong);
      z-index: 12;
      flex-shrink: 0;
    }

    /* Barra superior 2 (Pegada a la mesa): Herramientas directas del Diseño (Alinear, Tamaño, Rotación, Centrar, Eliminar) */
    .stage-design-Ribbon {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
      padding: 6px 14px;
      background: var(--surface-low);
      border-bottom: 1px solid var(--border-strong);
      z-index: 11;
      overflow-x: auto;
      scrollbar-width: none;
      flex-shrink: 0;
    }
    .stage-design-Ribbon::-webkit-scrollbar { display: none; }

    .ribbon-group {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      flex-shrink: 0;
    }

    .ribbon-divider {
      width: 1px;
      height: 24px;
      background: var(--border-strong);
      margin: 0 4px;
      flex-shrink: 0;
    }

    .ribbon-label {
      font-family: var(--font-mono);
      font-size: 10px;
      text-transform: uppercase;
      color: var(--text-muted);
      margin-right: 4px;
      white-space: nowrap;
    }

    .ribbon-input {
      width: 68px;
      height: 34px;
      padding: 0 6px;
      border: 1px solid var(--border-strong);
      background: var(--surface-solid);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 600;
      text-align: center;
    }

    .side-switcher {
      display: inline-flex;
      background: var(--surface-low);
      border: 1px solid var(--border-strong);
    }

    .side-tab {
      min-height: 34px;
      padding: 0 16px;
      border: none;
      background: transparent;
      font-family: var(--font-headline);
      font-weight: 600;
      font-size: 12px;
      letter-spacing: 0.05em;
      cursor: pointer;
      color: var(--text-secondary);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.12s ease;
    }

    .side-tab.active {
      background: var(--primary);
      color: var(--on-primary);
    }

    .side-dot {
      width: 6px;
      height: 6px;
      background: var(--accent-crimson);
      display: none;
    }

    .side-dot.has-content {
      display: inline-block;
    }

    .canvas-viewport {
      position: relative;
      flex: 1;
      width: 100%;
      height: 100%;
      overflow: hidden;
      touch-action: none;
      background-image:
        linear-gradient(45deg, var(--checker-a) 25%, transparent 25%),
        linear-gradient(-45deg, var(--checker-a) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, var(--checker-a) 75%),
        linear-gradient(-45deg, transparent 75%, var(--checker-a) 75%);
      background-size: 24px 24px;
      background-position: 0 0, 0 12px, 12px -12px, -12px 0;
      background-color: var(--checker-b);
    }

    #workbenchCanvas {
      display: block;
      width: 100%;
      height: 100%;
      cursor: grab;
    }

    #workbenchCanvas.dragging-design {
      cursor: move;
    }

    /* HUD de medidas en tiempo real en la parte inferior de la mesa */
    .stage-hud-bottom {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
      padding: 6px 14px;
      background: var(--surface-solid);
      border-top: 1px solid var(--border-strong);
      font-family: var(--font-mono);
      font-size: 11px;
      z-index: 10;
      overflow-x: auto;
      scrollbar-width: none;
      flex-shrink: 0;
    }
    .stage-hud-bottom::-webkit-scrollbar { display: none; }

    .hud-metrics {
      display: flex;
      gap: 14px;
      align-items: center;
      white-space: nowrap;
    }

    .hud-metric-item {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      color: var(--text-secondary);
    }

    .hud-metric-item strong {
      color: var(--text-primary);
      font-weight: 600;
    }

    .zoom-controls {
      display: inline-flex;
      align-items: center;
      gap: 2px;
      flex-shrink: 0;
    }

    .zoom-btn {
      min-width: 32px;
      min-height: 30px;
      padding: 0 8px;
      border: 1px solid var(--border-strong);
      background: var(--surface-low);
      cursor: pointer;
      font-family: var(--font-mono);
      font-size: 11px;
    }

    .zoom-btn:hover {
      background: var(--surface-high);
    }

    /* ==========================================================================
       7. MODAL DE RESUMEN DE DESCARGA Y NOTIFICACIONES (RECTOS Y FORMALES)
       ========================================================================== */
    .toast-banner {
      position: fixed;
      top: 64px;
      left: 50%;
      transform: translateX(-50%) translateY(-20px);
      background: var(--surface-solid);
      color: var(--text-primary);
      border: 1px solid var(--border-strong);
      border-left: 4px solid var(--accent-crimson);
      padding: 10px 18px;
      box-shadow: var(--shadow-long);
      font-family: var(--font-mono);
      font-size: 12px;
      font-weight: 500;
      z-index: 100;
      opacity: 0;
      pointer-events: none;
      transition: all 0.2s ease;
    }

    .toast-banner.visible {
      opacity: 1;
      transform: translateX(-50%) translateY(0);
      pointer-events: auto;
    }

    .modal-backdrop {
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.6);
      backdrop-filter: blur(4px);
      display: none;
      align-items: center;
      justify-content: center;
      padding: 20px;
      z-index: 90;
    }

    .modal-backdrop.open {
      display: flex;
    }

    .modal-card {
      background: var(--surface-solid);
      border: 1px solid var(--border-strong);
      max-width: 520px;
      width: 100%;
      padding: 24px;
      box-shadow: var(--shadow-long);
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .modal-title {
      font-family: var(--font-headline);
      font-size: 18px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.04em;
      display: flex;
      align-items: center;
      justify-content: space-between;
      border-bottom: 1px solid var(--border-subtle);
      padding-bottom: 10px;
    }

    .file-summary-list {
      list-style: none;
      background: var(--surface-low);
      border: 1px solid var(--border-strong);
      padding: 12px 14px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      font-family: var(--font-mono);
      font-size: 11px;
    }

    .file-summary-list li {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .file-tag {
      font-size: 10px;
      padding: 2px 6px;
      background: var(--surface-high);
      color: var(--text-secondary);
      border: 1px solid var(--border-subtle);
    }

    /* ==========================================================================
       8. RESPONSIVE REAL PULIDO (MÓVIL: MESA ARRIBA + DOCK + PESTAÑAS ABAJO)
       ========================================================================== */
    @media (max-width: 960px) {
      .top-navbar {
        padding: 0 10px;
        height: 46px;
      }

      .steps-bar {
        display: none; /* En móvil usamos la barra de pestañas dedicada del panel inferior */
      }

      .brand-logo span.sub-hide-mobile,
      .tag-chip.sub-hide-mobile {
        display: none;
      }

      .workspace-grid {
        grid-template-columns: 1fr;
        grid-template-rows: 58% 42%;
      }

      /* Mesa de trabajo arriba, controles abajo */
      .stage-container {
        order: 1;
      }

      .controls-panel {
        order: 2;
      }

      .mobile-panel-tabs {
        display: grid;
      }

      .bento-section {
        display: none;
        padding: 14px;
        border-bottom: none;
      }

      .bento-section.mobile-active {
        display: flex;
      }

      .stage-toolbar-top {
        padding: 4px 8px;
      }

      .stage-design-Ribbon {
        padding: 4px 8px;
      }

      .btn-icon, .side-tab, .zoom-btn, .ribbon-input {
        min-height: 40px;
        min-width: 40px;
      }
    }