/* ============================================
   CSS Variables & Reset
   ============================================ */
:root {
    /* Colors */
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --bg-overlay: rgba(0, 0, 0, 0.4);
    --bg-glass: rgba(255, 255, 255, 0.85);

    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;

    --accent-primary: #007AFF;
    --accent-secondary: #5856D6;
    --accent-success: #34C759;
    --accent-danger: #FF3B30;

    --border-light: rgba(0, 0, 0, 0.1);
    --border-medium: rgba(0, 0, 0, 0.15);

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.18);
    --shadow-float: 0 6px 20px rgba(0, 0, 0, 0.15);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-sm: 13px;
    --font-size-base: 15px;
    --font-size-lg: 17px;
    --font-size-xl: 20px;
    --font-size-2xl: 24px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Layout */
    --menu-width: 320px;
    --safe-area-inset-top: env(safe-area-inset-top);
    --safe-area-inset-bottom: env(safe-area-inset-bottom);
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2a2a2a;
    --bg-overlay: rgba(0, 0, 0, 0.6);
    --bg-glass: rgba(30, 30, 30, 0.9);

    --text-primary: #e8e8e8;
    --text-secondary: #aaaaaa;
    --text-muted: #777777;

    --border-light: rgba(255, 255, 255, 0.1);
    --border-medium: rgba(255, 255, 255, 0.15);

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
    --shadow-float: 0 6px 20px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] #viewer-container {
    background: linear-gradient(180deg, #1e1e1e 0%, #141414 100%);
}

[data-theme="dark"] .toggle-switch .toggle-slider {
    background-color: #555;
}

[data-theme="dark"] .toggle-switch input:checked + .toggle-slider {
    background-color: var(--accent-success);
}

[data-theme="dark"] .toggle-switch .toggle-slider::before {
    background-color: #e0e0e0;
}

/* Android-specific adjustments */
@supports (-webkit-touch-callout: none) {
    :root {
        --accent-primary: #007AFF;
    }
}

@supports not (-webkit-touch-callout: none) {
    :root {
        --accent-primary: #1976D2;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html,
body {
    height: 100%;
    overflow: hidden;
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.hidden {
    display: none !important;
}

/* ============================================
   3D Viewer Container
   ============================================ */
#viewer-container {
    position: fixed;
    inset: 0;
    background: linear-gradient(180deg, #fafafa 0%, #f0f0f0 100%);
}

#viewer-canvas {
    width: 100%;
    height: 100%;
    display: block;
    touch-action: none;
}

/* ============================================
   Loading Overlay
   ============================================ */
#loading-overlay {
    position: absolute;
    inset: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    z-index: 100;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-light);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-text {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    font-weight: 500;
}

/* ============================================
   Cutplane Slider
   ============================================ */
.cutplane-slider-container {
    position: absolute;
    right: 0px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 230px;
    z-index: 50;
    background: rgba(255, 255, 255, 0.5);
    border-radius: var(--radius-full);
    padding: 0;
}

.cutplane-slider-container.hidden {
    display: none;
}

.cutplane-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 200px;
    height: 8px;
    background: rgba(0, 48, 135, 0.3);
    border-radius: var(--radius-full);
    outline: none;
    transform: rotate(-90deg);
    transform-origin: center center;
    margin: 16px 0;
}

.cutplane-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    background: #003087;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
    transition: transform var(--transition-fast);
}

.cutplane-slider::-webkit-slider-thumb:active {
    transform: scale(1.1);
}

.cutplane-slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    background: #003087;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

/* ============================================
   Empty State Panel
   ============================================ */
.empty-state-panel {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    z-index: 10;
}

.empty-state-panel.hidden {
    display: none;
}

.empty-state-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-lg);
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 340px;
    width: 100%;
}

.empty-state-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: var(--spacing-sm);
}

.empty-state-icon {
    color: var(--text-muted);
    opacity: 0.6;
}

.empty-state-text {
    font-size: var(--font-size-base);
    color: var(--text-muted);
    font-weight: 500;
}

.empty-state-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    width: 100%;
    max-width: 280px;
}

.empty-state-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.empty-state-button:active {
    opacity: 0.8;
    transform: scale(0.98);
}

.empty-state-button.primary {
    background: var(--accent-primary);
    color: white;
}

.empty-state-button.secondary {
    background: var(--accent-secondary);
    color: white;
}

/* ============================================
   Floating Menu Button
   ============================================ */
.floating-button {
    position: fixed;
    top: calc(var(--spacing-md) + var(--safe-area-inset-top));
    left: var(--spacing-md);
    width: 48px;
    height: 48px;
    border: none;
    border-radius: var(--radius-md);
    background: #003087;
    box-shadow: var(--shadow-float);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: white;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    z-index: 50;
}

.floating-button:active {
    transform: scale(0.95);
    box-shadow: var(--shadow-sm);
}

/* ============================================
   Flyout Menu
   ============================================ */
#flyout-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    opacity: 0;
    transition: opacity var(--transition-base);
    z-index: 200;
}

#flyout-overlay:not(.hidden) {
    opacity: 1;
}

#flyout-menu {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--menu-width);
    max-width: 85vw;
    height: 100%;
    background: var(--bg-secondary);
    box-shadow: var(--shadow-lg);
    transform: translateX(-100%);
    transition: transform var(--transition-base);
    z-index: 300;
    display: flex;
    flex-direction: column;
    padding-top: var(--safe-area-inset-top);
    padding-bottom: var(--safe-area-inset-bottom);
}

#flyout-menu:not(.closed) {
    transform: translateX(0);
}

.menu-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg) var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.menu-header h1 {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

.icon-button {
    width: 44px;
    height: 44px;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: background var(--transition-fast);
}

.icon-button:active {
    background: var(--border-light);
}

/* Menu Tabs */
.menu-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-light);
    background: var(--bg-secondary);
}

.tab-button {
    flex: 1;
    padding: var(--spacing-md);
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: var(--font-size-base);
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    position: relative;
    transition: color var(--transition-fast);
}

.tab-button:active {
    background: var(--border-light);
}

.tab-button.active {
    color: var(--accent-primary);
    font-weight: 600;
}

.tab-button.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--accent-primary);
    border-radius: 3px 3px 0 0;
}

/* Tab Content */
.tab-content {
    display: block;
}

.tab-content.hidden {
    display: none;
}

.tab-content.active {
    display: block;
}

.menu-content {
    flex: 1;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

#parts-list {
    padding: var(--spacing-sm) 0;
}

.empty-state {
    padding: var(--spacing-xl);
    text-align: center;
    color: var(--text-muted);
    font-size: var(--font-size-base);
}

/* Views Tab Styles */
.views-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.save-view-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    background: var(--accent-primary);
    color: white;
    font-size: var(--font-size-base);
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.save-view-button:active {
    opacity: 0.8;
    transform: scale(0.98);
}

.save-view-button:disabled {
    background: var(--border-light);
    color: var(--text-muted);
    cursor: not-allowed;
    opacity: 0.6;
}

.save-view-button:disabled:active {
    transform: none;
}

#views-list {
    padding: var(--spacing-sm) 0;
}

.view-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
    gap: var(--spacing-md);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.view-item:active {
    background: var(--border-light);
}

.view-item-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.view-item-name-row {
    display: flex;
    align-items: center;
    gap: 6px;
    min-width: 0;
}

.view-item-name {
    font-size: var(--font-size-base);
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Feature icons in views list */
.view-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    border-radius: 4px;
    flex-shrink: 0;
    font-size: 11px;
    font-weight: 700;
    line-height: 1;
}

.view-icon-measurement {
    background: var(--accent-primary);
    color: #ffffff;
}

.view-icon-spline {
    background: #00c010;
    color: #ffffff;
}

.view-icon-spline svg {
    width: 14px;
    height: 14px;
}

.view-item-timestamp {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
}

.view-item-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    flex-shrink: 0;
}

.delete-view-button {
    width: 36px;
    height: 36px;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--accent-danger);
    transition: background var(--transition-fast);
}

.delete-view-button:active {
    background: rgba(255, 59, 48, 0.1);
}

.delete-view-button svg {
    width: 18px;
    height: 18px;
}

.export-spline-button {
    width: 36px;
    height: 36px;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--accent-primary);
    transition: background var(--transition-fast);
}

.export-spline-button:active {
    background: rgba(10, 132, 255, 0.15);
}

.export-spline-button svg {
    width: 18px;
    height: 18px;
}

/* Part Item */
.part-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
    gap: var(--spacing-md);
}

.part-info {
    flex: 1;
    min-width: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.part-color {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    border: 1px solid var(--border-medium);
    flex-shrink: 0;
}

.part-name {
    font-size: var(--font-size-base);
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Part Controls Container */
.part-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-shrink: 0;
}

/* Transparency Toggle Button */
.transparency-button {
    width: 36px;
    height: 36px;
    border: none;
    border-radius: var(--radius-sm);
    background: var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

.transparency-button:active {
    transform: scale(0.95);
}

.transparency-button.active {
    background: var(--accent-primary);
    color: white;
}

.transparency-button svg {
    width: 18px;
    height: 18px;
}

/* iOS-style Toggle Switch */
.toggle-switch {
    position: relative;
    width: 51px;
    height: 31px;
    flex-shrink: 0;
}

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

.toggle-slider {
    position: absolute;
    inset: 0;
    background-color: #e9e9eb;
    border-radius: var(--radius-full);
    transition: background-color var(--transition-fast);
    cursor: pointer;
}

.toggle-slider::before {
    content: '';
    position: absolute;
    width: 27px;
    height: 27px;
    left: 2px;
    bottom: 2px;
    background-color: white;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    transition: transform var(--transition-fast);
}

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

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

/* Small toggle switch variant */
.toggle-switch.small {
    width: 40px;
    height: 24px;
}

.toggle-switch.small .toggle-slider::before {
    width: 20px;
    height: 20px;
}

.toggle-switch.small input:checked+.toggle-slider::before {
    transform: translateX(16px);
}

/* Label Mode Switch */
.label-mode-switch {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    margin-bottom: var(--spacing-sm);
}

.label-mode-option {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.label-mode-option[data-mode="always"].active,
.label-mode-option[data-mode="longpress"].active {
    color: var(--text-primary);
    font-weight: 600;
}

/* Dark Mode Switch */
.dark-mode-switch {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    margin-bottom: var(--spacing-sm);
}

.dark-mode-switch .theme-icon {
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

[data-theme="dark"] .dark-mode-switch .theme-icon:last-of-type {
    color: var(--text-primary);
}

:root:not([data-theme="dark"]) .dark-mode-switch .theme-icon:first-of-type {
    color: var(--text-primary);
}

/* Measurements Overlay - Floating panel in viewer */
.measurements-overlay {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 280px;
    max-height: 400px;
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    z-index: 10;
    transition: var(--transition-base);
}

.measurements-overlay.hidden {
    display: none;
}

.measurements-overlay-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.close-measurements-button {
    background: transparent;
    border: none;
    padding: 4px;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-sm);
    transition: var(--transition-fast);
}

.close-measurements-button:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

#measurements-list {
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    flex: 1;
}

.measurement-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md) 0;
    gap: var(--spacing-sm);
}

.measurement-label {
    flex: 1;
    min-width: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.measurement-color {
    width: 12px;
    height: 12px;
    border-radius: 3px;
    border: 1px solid var(--border-medium);
    flex-shrink: 0;
}

.measurement-name {
    font-size: var(--font-size-sm);
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.measurement-value {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--accent-primary);
    white-space: nowrap;
    flex-shrink: 0;
}

.measurement-unit {
    font-size: var(--font-size-sm);
    font-weight: 400;
    color: var(--text-muted);
    margin-left: 2px;
}

.measurement-values {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 2px;
    flex-shrink: 0;
}

.measurement-dimensions {
    display: flex;
    gap: var(--spacing-sm);
    font-size: 11px;
    font-weight: 500;
    color: var(--text-secondary);
}

.dimension-max {
    color: var(--text-primary);
}

.dimension-min {
    color: var(--text-muted);
}

.measurement-hydraulic {
    display: flex;
    gap: var(--spacing-sm);
    font-size: 11px;
    font-weight: 500;
    color: var(--text-secondary);
}

.dimension-hydraulic {
    color: var(--text-primary);
}

/* Dimension Labels on Cutplane (CSS2D) */
.dimension-label {
    font-family: var(--font-family);
    font-size: 12px;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: 4px;
    white-space: nowrap;
    pointer-events: none;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.dimension-label-max {
    background: rgba(0, 0, 0, 0.65);
    color: #ffffff;
}

.dimension-label-min {
    background: rgba(255, 255, 255, 0.75);
    color: #333333;
    border: 1px solid rgba(0, 0, 0, 0.2);
}

.dimension-label-dh {
    background: rgba(30, 100, 200, 0.75);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.dimension-label-spline {
    background: rgba(80, 179, 0, 0.85);
    color: #ffffff;
    border: 1px solid rgba(104, 230, 0, 0.5);
}

.dimension-label-letter {
    background: rgba(0, 0, 0, 0.8);
    color: #ffffff;
    font-size: 12px;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 10px;
    min-width: 24px;
    text-align: center;
    border: 2px solid rgba(255, 255, 255, 0.6);
}

/* Measurements header actions */
.measurements-header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.measurements-clear-all {
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--border-radius-sm);
    transition: var(--transition-fast);
}

.measurements-clear-all:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

/* Editable measurement name input */
.measurement-name-input {
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    font-weight: 600;
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--border-radius-sm);
    padding: 2px 4px;
    color: var(--text-primary);
    width: 80px;
    transition: var(--transition-fast);
}

.measurement-name-input:hover {
    border-color: var(--border-medium);
}

.measurement-name-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: var(--bg-surface);
}

/* Part name in measurement row */
.measurement-part-name {
    font-size: 11px;
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    min-width: 0;
}

/* Measurement item action buttons container */
.measurement-item-actions {
    display: flex;
    align-items: center;
    gap: 2px;
    flex-shrink: 0;
}

/* Pin measurement button */
.measurement-pin-button {
    background: transparent;
    border: none;
    padding: 4px;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-sm);
    transition: var(--transition-fast);
}

.measurement-pin-button:hover {
    background: rgba(0, 122, 255, 0.1);
    color: var(--accent-primary);
}

.measurement-pin-button.pinned {
    color: var(--accent-primary);
}

/* Remove measurement button */
.measurement-remove-button {
    background: transparent;
    border: none;
    padding: 4px;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-sm);
    transition: var(--transition-fast);
    flex-shrink: 0;
}

.measurement-remove-button:hover {
    background: rgba(220, 50, 50, 0.1);
    color: #dc3232;
}

/* Measurement detail rows (area, axes, perimeter, Dh) */
.measurement-detail-rows {
    padding: 4px var(--spacing-md) var(--spacing-sm);
    border-bottom: 1px solid var(--border-light);
}

.measurement-detail-rows:last-child {
    border-bottom: none;
}

.measurement-detail-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1px 0;
    font-size: 11px;
}

.measurement-detail-label {
    color: var(--text-muted);
    font-weight: 500;
}

.measurement-detail-value {
    color: var(--text-primary);
    font-weight: 600;
}

/* Instruction text for tap-to-select */
.measurement-instruction {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    padding: var(--spacing-md);
    text-align: center;
    font-style: italic;
}

/* Long-press Popup Label */
.popup-label {
    position: fixed;
    padding: 10px 18px;
    border-radius: 24px;
    font-family: var(--font-family);
    font-size: 14px;
    font-weight: 600;
    color: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    pointer-events: auto;
    z-index: 200;
    animation: popupFadeIn 0.2s ease-out;
    cursor: pointer;
}

@keyframes popupFadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Menu Footer */
.menu-footer {
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.menu-action-row {
    display: flex;
    gap: var(--spacing-sm);
}

.menu-action-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    flex: 1;
    min-width: 0;
    padding: var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    background: var(--accent-primary);
    color: white;
    font-size: var(--font-size-base);
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.menu-action-button:active {
    opacity: 0.8;
    transform: scale(0.98);
}

.menu-action-button:nth-child(1) {
    background: var(--accent-primary);
}

.menu-action-button:nth-child(2) {
    background: var(--accent-secondary);
}

.menu-action-button.secondary {
    background: #6c757d;
}

.menu-action-button.secondary.active {
    background: var(--accent-success);
}

/* ============================================
   Part Labels (CSS2D)
   ============================================ */
.part-label-container {
    pointer-events: none;
    transform: translate(-50%, -50%);
}

.part-label-text {
    display: inline-block;
    position: relative;
    padding: 6px 14px;
    border-radius: 20px;
    font-family: var(--font-family);
    font-size: 13px;
    font-weight: 600;
    white-space: nowrap;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

/* ============================================
   QR Scanner Modal
   ============================================ */
.modal {
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 500;
    padding: var(--spacing-md);
}

.modal-content {
    width: 100%;
    max-width: 400px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    animation: modalIn var(--transition-base) ease-out;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.modal-header h2 {
    font-size: var(--font-size-lg);
    font-weight: 600;
}

#qr-reader {
    width: 100%;
    aspect-ratio: 1;
    background: #000;
}

#qr-reader video {
    object-fit: cover;
}

.qr-instructions {
    padding: var(--spacing-md);
    text-align: center;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

/* ============================================
   Toast Notifications
   ============================================ */
.toast {
    position: fixed;
    bottom: calc(var(--spacing-xl) + var(--safe-area-inset-bottom));
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 600;
    animation: toastIn var(--transition-base) ease-out;
}

@keyframes toastIn {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* ============================================
   Tutorial System
   ============================================ */

/* Hint toast with arrow pointing to menu button */
.tutorial-hint {
    position: fixed;
    top: calc(var(--spacing-md) + var(--safe-area-inset-top) + 6px);
    left: calc(var(--spacing-md) + 56px);
    display: flex;
    align-items: center;
    gap: 2px;
    background: #1a1a1a;
    color: #ffffff;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 60;
    white-space: nowrap;
    animation: tutorialHintLifecycle 5s ease forwards;
    pointer-events: none;
}

.tutorial-hint.hidden {
    display: none !important;
}

.tutorial-hint-arrow {
    font-size: 12px;
    margin-right: 2px;
    line-height: 1;
}

@keyframes tutorialHintLifecycle {
    0% {
        opacity: 0;
        transform: translateX(-8px);
    }
    8% {
        opacity: 1;
        transform: translateX(0);
    }
    75% {
        opacity: 1;
        transform: translateX(0);
    }
    100% {
        opacity: 0;
        transform: translateX(0);
    }
}

/* Tutorial overlay (shared between gesture and menu steps) */
.tutorial-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 700;
    padding: var(--spacing-md);
    animation: tutorialOverlayIn var(--transition-base) ease-out;
}

.tutorial-overlay.hidden {
    display: none !important;
}

@keyframes tutorialOverlayIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.tutorial-content {
    width: 100%;
    max-width: 360px;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-lg);
    animation: modalIn var(--transition-base) ease-out;
}

.tutorial-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.tutorial-items {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.tutorial-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-sm);
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.04);
}

.tutorial-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--accent-primary);
}

.tutorial-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.tutorial-text strong {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-primary);
}

.tutorial-text span {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    line-height: 1.3;
}

.tutorial-button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    background: var(--accent-primary);
    color: white;
    font-size: var(--font-size-base);
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.tutorial-button:active {
    opacity: 0.8;
    transform: scale(0.98);
}

/* ============================================
   Responsive Adjustments
   ============================================ */
@media (max-width: 380px) {
    :root {
        --menu-width: 100vw;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1c1c1e;
        --bg-secondary: #2c2c2e;
        --bg-glass: rgba(44, 44, 46, 0.85);
        --text-primary: #ffffff;
        --text-secondary: #ebebf5;
        --text-muted: #8e8e93;
        --border-light: rgba(255, 255, 255, 0.1);
        --border-medium: rgba(255, 255, 255, 0.15);
    }

    #viewer-container {
        background: linear-gradient(180deg, #2c2c2e 0%, #1c1c1e 100%);
    }

    .toggle-slider {
        background-color: #39393d;
    }
}