:root {
  --bg-page: #f1f5f9;
  --bg-panel: #ffffff;
  --bg-card: #f8fafc;
  --bg-card-hover: #f1f5f9;
  --bg-card-active: #eff6ff;
  --border-color: #e2e8f0;
  --border-active: #2563eb;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-soft: #dbeafe;
  --success-bg: #ecfdf5;
  --success-border: #10b981;
  --success-text: #065f46;
  --warn-bg: #fffbeb;
  --warn-border: #f59e0b;
  --warn-text: #92400e;
  --danger-bg: #fef2f2;
  --danger-border: #ef4444;
  --danger-text: #991b1b;
  --cut-color: #0f172a;
  --crease-color: #2563eb;
  --glue-color: #94a3b8;
  --dim-color: #059669;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.45;
  font-size: 14px;
  overflow-x: hidden;
}

/* Header */
.app-header {
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  position: sticky;
  top: 0;
  z-index: 40;
  box-shadow: var(--shadow-sm);
}

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

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.25);
}

.brand-title h1 {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
}

.brand-title p {
  font-size: 12px;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  font-size: 13px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 1px 3px rgba(37, 99, 235, 0.3);
}

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

.btn-secondary {
  background: #ffffff;
  color: var(--text-main);
  border-color: #cbd5e1;
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: #94a3b8;
}

.btn-accent {
  background: #0f172a;
  color: #ffffff;
}

.btn-accent:hover {
  background: #1e293b;
}

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

/* Main Layout */
.app-layout {
  display: grid;
  grid-template-columns: 420px 1fr;
  min-height: calc(100vh - 63px);
}

/* Sidebar Controls */
.sidebar {
  background: var(--bg-panel);
  border-right: 1px solid var(--border-color);
  padding: 16px;
  overflow-y: auto;
  max-height: calc(100vh - 63px);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.section-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

.section-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 6px;
}

.section-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary-hover);
}

/* Category filter tabs */
.cat-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  background: #e2e8f0;
  padding: 3px;
  border-radius: var(--radius-sm);
}

.cat-tab {
  border: none;
  background: transparent;
  padding: 6px 8px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: 4px;
  cursor: pointer;
}

.cat-tab.active {
  background: #ffffff;
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}

/* Model Grid */
.model-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.model-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
  padding: 9px 10px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-color);
  background: #ffffff;
  cursor: pointer;
  text-align: left;
  transition: all 0.15s ease;
  position: relative;
}

.model-card:hover {
  border-color: #94a3b8;
  background: var(--bg-card-hover);
}

.model-card.active {
  border-color: var(--border-active);
  background: var(--bg-card-active);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.12);
}

.model-card-top {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
}

.model-thumb {
  width: 42px;
  height: 36px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f8fafc;
  border-radius: 4px;
  border: 1px solid #e2e8f0;
}

.model-card.active .model-thumb {
  background: #ffffff;
  border-color: #bfdbfe;
}

.model-name {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.25;
}

.model-desc {
  font-size: 11px;
  color: var(--text-light);
  line-height: 1.25;
}

/* Dimension Sliders & Number Inputs */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.control-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-main);
}

.control-unit {
  font-size: 11px;
  color: var(--text-light);
  font-weight: 500;
}

.control-inputs {
  display: grid;
  grid-template-columns: 1fr 78px;
  align-items: center;
  gap: 10px;
}

.control-inputs input[type="range"] {
  width: 100%;
  accent-color: var(--primary);
  cursor: pointer;
}

.number-box {
  position: relative;
  display: flex;
  align-items: center;
}

.number-box input[type="number"] {
  width: 100%;
  padding: 5px 24px 5px 8px;
  font-size: 13px;
  font-weight: 600;
  border: 1px solid #cbd5e1;
  border-radius: var(--radius-sm);
  color: var(--text-main);
  background: #ffffff;
}

.number-box span {
  position: absolute;
  right: 6px;
  font-size: 11px;
  color: var(--text-light);
  pointer-events: none;
}

/* Preset Pills */
.presets-wrap {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.presets-label {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-muted);
}

.preset-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset-chip {
  font-size: 11.5px;
  font-weight: 600;
  padding: 4px 9px;
  border-radius: 999px;
  border: 1px solid #cbd5e1;
  background: #ffffff;
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.12s ease;
}

.preset-chip:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: #eff6ff;
}

.preset-chip small {
  color: var(--text-light);
  font-weight: 500;
  margin-left: 3px;
}

/* Sheet & Technical Options */
.sheet-selector {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.sheet-btn {
  padding: 9px 10px;
  border-radius: var(--radius-sm);
  border: 1.5px solid #cbd5e1;
  background: #ffffff;
  cursor: pointer;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sheet-btn.active {
  border-color: var(--primary);
  background: var(--bg-card-active);
}

.sheet-btn strong {
  font-size: 13px;
  color: var(--text-main);
}

.sheet-btn span {
  font-size: 11px;
  color: var(--text-light);
}

.segmented-row {
  display: flex;
  gap: 6px;
}

.seg-btn {
  flex: 1;
  padding: 6px 8px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid #cbd5e1;
  background: #ffffff;
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text-muted);
}

.seg-btn.active {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

.checkbox-list {
  display: flex;
  flex-direction: column;
  gap: 7px;
  margin-top: 4px;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--text-main);
  cursor: pointer;
  user-select: none;
}

.checkbox-item input {
  width: 15px;
  height: 15px;
  accent-color: var(--primary);
}

/* Workspace Area */
.workspace {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
  max-height: calc(100vh - 63px);
}

/* Fit Status Banner */
.fit-banner {
  border-radius: var(--radius-md);
  padding: 12px 16px;
  border: 1.5px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  box-shadow: var(--shadow-sm);
}

.fit-banner.status-green {
  background: var(--success-bg);
  border-color: var(--success-border);
  color: var(--success-text);
}

.fit-banner.status-amber {
  background: var(--warn-bg);
  border-color: var(--warn-border);
  color: var(--warn-text);
}

.fit-banner.status-red {
  background: var(--danger-bg);
  border-color: var(--danger-border);
  color: var(--danger-text);
}

.fit-info {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 240px;
}

.fit-badge-pill {
  font-size: 12px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  flex-shrink: 0;
}

.status-green .fit-badge-pill {
  background: #10b981;
  color: #ffffff;
}

.status-amber .fit-badge-pill {
  background: #f59e0b;
  color: #ffffff;
}

.status-red .fit-badge-pill {
  background: #ef4444;
  color: #ffffff;
}

.fit-text h2 {
  font-size: 14px;
  font-weight: 700;
}

.fit-text p {
  font-size: 12.5px;
  opacity: 0.92;
}

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

/* View Toolbar */
.workspace-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  background: var(--bg-panel);
  padding: 10px 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.view-mode-tabs {
  display: flex;
  gap: 6px;
}

.view-tab {
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid #cbd5e1;
  background: #ffffff;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
}

.view-tab.active {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

.legend-pills {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--text-muted);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
}

.legend-line-cut {
  width: 22px;
  height: 0;
  border-top: 2.5px solid var(--cut-color);
}

.legend-line-crease {
  width: 22px;
  height: 0;
  border-top: 2px dashed var(--crease-color);
}

.legend-box-glue {
  width: 16px;
  height: 11px;
  background: repeating-linear-gradient(
    45deg,
    #cbd5e1,
    #cbd5e1 2px,
    #f1f5f9 2px,
    #f1f5f9 5px
  );
  border: 1px solid #64748b;
}

/* Canvas Split Area */
.canvas-grid {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 14px;
  flex: 1;
  min-height: 520px;
}

.canvas-grid.mode-2d {
  grid-template-columns: 1fr;
}

.canvas-grid.mode-2d .panel-3d {
  display: none;
}

.canvas-grid.mode-3d {
  grid-template-columns: 1fr;
}

.canvas-grid.mode-3d .panel-2d {
  display: none;
}

.canvas-panel {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.panel-bar {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  background: #f8fafc;
  flex-wrap: wrap;
}

.panel-bar-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel-bar-sub {
  font-size: 11.5px;
  color: var(--text-light);
  font-weight: 500;
}

.svg-stage-wrap {
  flex: 1;
  background: #e2e8f0;
  background-image: radial-gradient(#cbd5e1 1px, transparent 1px);
  background-size: 16px 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  position: relative;
  min-height: 440px;
  overflow: auto;
}

#dieline-svg-container {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
}

#dieline-svg-container svg {
  max-width: 100%;
  max-height: 580px;
  width: auto;
  height: auto;
  filter: drop-shadow(0 8px 20px rgba(15, 23, 42, 0.14));
  border-radius: 2px;
}

/* 3D Stage */
.stage-3d-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: linear-gradient(180deg, #f8fafc 0%, #e2e8f0 100%);
  position: relative;
  min-height: 440px;
}

#canvas-3d {
  width: 100%;
  flex: 1;
  cursor: grab;
  display: block;
}

#canvas-3d:active {
  cursor: grabbing;
}

.controls-3d-bar {
  padding: 12px 14px;
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.fold-slider-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.fold-slider-row label {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--text-main);
  min-width: 120px;
}

.fold-slider-row input[type="range"] {
  flex: 1;
  accent-color: var(--primary);
}

.fold-pct-badge {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-soft);
  padding: 2px 8px;
  border-radius: 999px;
  min-width: 48px;
  text-align: center;
}

.cam-presets-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  flex-wrap: wrap;
}

.cam-presets-row span {
  font-size: 11.5px;
  color: var(--text-light);
}

/* Info Cards Footer */
.specs-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.spec-box {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
}

.spec-box-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-light);
  text-transform: uppercase;
}

.spec-box-val {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 2px;
}

.hidden {
  display: none !important;
}

/* Responsive Mobile (390px) */
@media (max-width: 980px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
  .sidebar {
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }
  .workspace {
    max-height: none;
    padding: 12px;
  }
  .canvas-grid {
    grid-template-columns: 1fr;
  }
  .specs-strip {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .app-header {
    padding: 10px 12px;
  }
  .brand-title h1 {
    font-size: 15px;
  }
  .header-actions {
    width: 100%;
    justify-content: stretch;
  }
  .header-actions .btn {
    flex: 1;
    padding: 8px 10px;
    font-size: 12px;
  }
  .model-grid {
    grid-template-columns: 1fr 1fr;
  }
  .fit-banner {
    padding: 10px 12px;
  }
}

/* Dual-file Export Buttons & Face Customization Controls */
.btn-success {
  background: linear-gradient(135deg, #059669, #047857);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(5, 150, 105, 0.28);
}

.btn-success:hover {
  background: #047857;
}

.face-tabs-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.face-chip {
  font-size: 11.5px;
  font-weight: 600;
  padding: 5px 9px;
  border-radius: 6px;
  border: 1.5px solid #cbd5e1;
  background: #ffffff;
  color: var(--text-main);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all 0.12s ease;
}

.face-chip:hover {
  border-color: var(--primary);
  background: #f8fafc;
}

.face-chip.active {
  border-color: var(--primary);
  background: var(--bg-card-active);
  color: var(--primary-hover);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.12);
}

.face-color-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1px solid rgba(15, 23, 42, 0.25);
  flex-shrink: 0;
}

.art-preset-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px;
}

.art-preset-btn {
  padding: 6px 8px;
  font-size: 11.5px;
  font-weight: 600;
  border-radius: 6px;
  border: 1.5px solid #cbd5e1;
  background: #ffffff;
  color: var(--text-main);
  cursor: pointer;
  text-align: left;
  display: flex;
  align-items: center;
  gap: 6px;
}

.art-preset-btn.active {
  border-color: var(--primary);
  background: var(--bg-card-active);
  color: var(--primary-hover);
}

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

.file-upload-label {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 10px;
  font-size: 12px;
  font-weight: 600;
  border: 1.5px dashed #3b82f6;
  border-radius: var(--radius-sm);
  background: #eff6ff;
  color: #1d4ed8;
  cursor: pointer;
}

.file-upload-label:hover {
  background: #dbeafe;
}

.color-picker-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.color-picker-row input[type="color"] {
  width: 44px;
  height: 28px;
  border: 1px solid #cbd5e1;
  border-radius: 4px;
  padding: 1px;
  background: #ffffff;
  cursor: pointer;
}

.doc-mode-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 999px;
  background: #dbeafe;
  color: #1e40af;
}

.doc-mode-pill.clean-print {
  background: #d1fae5;
  color: #065f46;
}