:root {
            --ui-bg: #f5f7fb;
            --panel-bg: #ffffff;
            --panel-strong: #ffffff;
            --panel-border: #e5e7eb;
            --panel-shadow: none;
            --panel-shadow-strong: none;
            --panel-radius: 0;
            --panel-radius-sm: 0;
            --text-muted: #6b7280;
            --text-strong: #111827;
            --accent: #2563eb;
            --z-base: 0;
            --z-main: 1;
            --z-canvas-stage: 1;
            --z-properties-popover: 40;
            --z-resize-handles: 80;
            --z-resize-handle-knob: 1;
            --z-floating-context: 220;
            --z-desktop-toolbar: 320;
            --z-mobile-tabs: 360;
            --z-mobile-popover: 380;
            --z-mobile-backdrop: 900;
            --z-mobile-sheet: 910;
            --z-top-info: 1200;
            --z-top-nav: 1210;
            --z-modal-crop: 2200;
            --z-modal-cart: 2210;
            --z-modal-handle: 2220;
            --z-loading: 3000;
        }

        body {
            background: var(--ui-bg);
        }

        .canvas-container {
            background: #f8f9fa;
            background-image:
                linear-gradient(rgba(0, 0, 0, .05) 1px, transparent 1px),
                linear-gradient(90deg, rgba(0, 0, 0, .05) 1px, transparent 1px);
            background-size: 20px 20px;
            border-radius: 16px;
            border: 1px solid var(--panel-border);
            box-shadow: var(--panel-shadow);
        }

        .element-selected {
            outline: 2px solid #2563eb;
            outline-offset: 2px;
        }

        body.is-resizing-element .element-selected {
            outline: none !important;
            outline-offset: 0 !important;
        }

        .resize-handle {
            width: 12px;
            height: 12px;
            background: white;
            border: 2px solid #2563eb;
            border-radius: 50%;
            position: absolute;
            cursor: pointer;
            z-index: var(--z-resize-handle-knob);
            touch-action: none;
            -webkit-touch-callout: none;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
            pointer-events: auto;
        }

        .resize-handle::before {
            content: '';
            position: absolute;
            inset: -8px;
            cursor: inherit;
        }

        .resize-handle:hover {
            background: #2563eb;
            transform: scale(1.4);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
        }

        .rotate-handle {
            width: 36px;
            height: 36px;
            position: absolute;
            cursor: grab;
            z-index: var(--z-resize-handle-knob);
            color: #2563eb;
            touch-action: none;
            -webkit-touch-callout: none;
            display: flex;
            align-items: center;
            justify-content: center;
            background: white;
            border: 2px solid #2563eb;
            border-radius: 50%;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
            pointer-events: auto;
        }

        .rotate-handle::before {
            content: '';
            position: absolute;
            inset: -8px;
            cursor: inherit;
        }

        .rotate-handle:hover {
            background: #f0f4ff;
            transform: scale(1.15);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
        }

        .rotate-handle:active {
            cursor: grabbing;
        }

        .panel-clean {
            background: var(--panel-strong);
            border: 1px solid var(--panel-border);
            box-shadow: none;
        }

        .sidebar-shell {
            background: #ffffff;
            border: 1px solid var(--panel-border);
            border-radius: 0;
            box-shadow: none;
            backdrop-filter: none;
            -webkit-backdrop-filter: none;
            height: 100%;
            display: flex;
            flex-direction: column;
            overflow: hidden;
            position: relative;
        }

        .sidebar-section {
            padding: 0.9rem 1rem 1rem;
        }

        .sidebar-section+.sidebar-section {
            border-top: 1px solid var(--panel-border);
        }

        #elements-panel,
        #properties-panel,
        #layers-panel {
            flex: 1 1 auto;
            min-height: 0;
            scrollbar-gutter: stable both-edges;
            overscroll-behavior: contain;
        }

        #elements-panel {
            display: flex;
            flex-direction: column;
            overflow: visible;
            gap: 1rem;
            justify-content: flex-start;
            flex: 0 0 auto;
        }

        #layers-panel {
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
            overflow: hidden;
            min-height: 0;
            padding-bottom: 0.9rem;
        }

        #layers-panel .elements-group {
            flex: 1 1 auto;
            min-height: 0;
        }

        #layers-list {
            flex: 1 1 auto;
            min-height: 0;
            overflow-y: auto;
            overflow-x: hidden;
            padding-right: 0.35rem;
            padding-bottom: 0.25rem;
        }

        #properties-panel {
            display: flex;
            flex-direction: row;
            align-items: flex-start;
            gap: 0.75rem;
            flex-wrap: wrap;
            padding: 0.55rem 1rem 0.7rem;
            position: relative;
            overflow: visible;
        }

        .section-title {
            display: none;
            font-size: 0.7rem;
            text-transform: uppercase;
            letter-spacing: 0.14em;
            font-weight: 700;
            color: var(--text-muted);
            margin-bottom: 0.7rem;
        }

        .elements-group {
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
            padding-bottom: 0;
        }

        .elements-group-title {
            margin: 0;
            font-size: 0.7rem;
            font-weight: 800;
            letter-spacing: 0.14em;
            text-transform: uppercase;
            color: #64748b;
        }

        .elements-grid {
            display: grid;
            grid-template-columns: repeat(2, minmax(0, 1fr));
            gap: 0.6rem;
        }

        .elements-grid--compact {
            grid-template-columns: repeat(2, minmax(0, 1fr));
        }

        .element-card,
        .shape-card {
            width: 100%;
            min-width: 0;
            border: 1px solid #dbe3ee;
            background: #ffffff;
            border-radius: 16px;
            text-align: left;
            transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
        }

        .element-card {
            display: flex;
            align-items: center;
            gap: 0.8rem;
            padding: 0.82rem 0.88rem;
            min-height: 4rem;
            box-shadow: none;
        }

        .tool-tile:hover,
        .shape-tile:hover,
        .element-card:hover,
        .shape-card:hover {
            transform: translateY(-1px);
            border-color: #bfd3f7;
            box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
            background: #f8fbff;
        }

        .element-card__icon,
        .shape-card__icon,
        .tool-tile__icon,
        .shape-tile__icon {
            flex-shrink: 0;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 2.35rem;
            height: 2.35rem;
            border-radius: 12px;
            background: #eff6ff;
            color: #2563eb;
        }

        .element-card__icon--dark,
        .tool-tile--dark .tool-tile__icon,
        .tool-tile__icon.tool-tile--dark {
            background: #0f172a;
            color: #ffffff;
        }

        .element-card__icon--neutral,
        .tool-tile--neutral .tool-tile__icon {
            background: #f1f5f9;
            color: #334155;
        }

        .element-card--green .element-card__icon,
        .tool-tile--green .tool-tile__icon {
            background: #ecfdf5;
            color: #059669;
        }

        .element-card--slate .element-card__icon,
        .tool-tile--slate .tool-tile__icon {
            background: #e2e8f0;
            color: #0f172a;
        }

        .element-card__body,
        .shape-card__body {
            min-width: 0;
            display: flex;
            flex-direction: column;
            gap: 0.1rem;
        }

        .element-card__title,
        .shape-card__title,
        .tool-tile__label {
            display: block;
            font-size: 0.84rem;
            font-weight: 800;
            color: #0f172a;
            line-height: 1.15;
            letter-spacing: -0.01em;
        }

        .element-card__meta,
        .shape-card__meta {
            display: none;
        }

        .tool-tile {
            display: flex;
            align-items: center;
            gap: 0.7rem;
            width: 100%;
            min-width: 0;
            padding: 0.8rem 0.9rem;
            border-radius: 12px;
            border: 1px solid var(--panel-border);
            background: #ffffff;
            box-shadow: none;
            min-height: 3.8rem;
        }

        .tool-tile__label {
            white-space: nowrap;
        }

        .shape-grid {
            display: grid;
            grid-template-columns: repeat(4, minmax(0, 1fr));
            gap: 0.6rem;
        }

        .shape-tile {
            display: grid;
            place-items: center;
            gap: 0;
            width: 100%;
            aspect-ratio: 1 / 1;
            padding: 0;
            min-height: 0;
            border-radius: 12px;
            border: 1px solid var(--panel-border);
            background: #ffffff;
            box-shadow: none;
        }

        .shape-btn.shape-tile {
            width: 100%;
        }

        .shape-tile__icon {
            width: 2.2rem;
            height: 2.2rem;
            border-radius: 12px;
            background: #f3f4f6;
            color: #0f172a;
        }

        .shape-tile__icon svg {
            width: 1.05rem;
            height: 1.05rem;
        }

        .tool-tile--blue {
            background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);
        }

        .action-btn {
            border: 1px solid var(--panel-border);
            background: #ffffff;
            color: #334155;
            border-radius: 12px;
            padding: 0.72rem 0.84rem;
            font-size: 0.8rem;
            font-weight: 600;
            transition: border-color 0.18s ease, background-color 0.18s ease, color 0.18s ease;
            box-shadow: none;
        }

        .action-btn:hover {
            background: #f9fafb;
            border-color: #d1d5db;
            color: #1d4ed8;
            transform: none;
            box-shadow: none;
        }

        #text-properties.active input,
        #text-properties.active select,
        #text-properties.active button {
            border-left: 3px solid #2563eb;
            border-radius: 8px 10px 10px 8px;
        }

        #text-properties.active input:focus,
        #text-properties.active select:focus,
        #text-properties.active button:focus {
            outline: none;
            border-left-color: #1d4ed8;
            box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
        }

        #text-properties.active {
            background: #ffffff;
            border: 1px solid var(--panel-border);
            border-radius: 0;
            padding: 0.85rem 0;
            margin-top: 0;
        }

        #text-properties,
        #image-properties,
        #shape-properties {
            border: 1px solid var(--panel-border);
            background: #ffffff;
            border-radius: 0;
            padding: 0.85rem;
            box-shadow: none;
            flex: 1 1 260px;
            min-width: 240px;
        }

        #no-selection {
            border: 1px dashed var(--panel-border);
            border-radius: 0;
            background: #ffffff;
            box-shadow: none;
            color: #94a3b8;
            flex: 1 1 100%;
            min-height: 0;
            display: flex;
            flex-direction: row;
            align-items: center;
            justify-content: flex-start;
            gap: 0.75rem;
            padding: 0.7rem 0.85rem;
        }

        #layers-list {
            display: flex;
            flex-direction: column;
            gap: 0.65rem;
        }

        .layer-item {
            border: 1px solid var(--panel-border);
            background: #ffffff;
            border-radius: 0;
            box-shadow: none;
            transition: border-color 0.18s ease, background-color 0.18s ease;
            padding: 0.7rem 0.8rem;
        }

        .layer-item:hover {
            transform: none;
            border-color: #d1d5db;
            box-shadow: none;
            background: #f9fafb;
        }

        .upload-crop-modal {
            position: fixed;
            inset: 0;
            z-index: var(--z-modal-crop);
            background: rgba(15, 23, 42, 0.78);
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1.25rem;
        }

        .upload-crop-modal.hidden {
            display: none;
        }

        #canvas-wrapper.drop-target {
            outline: 3px dashed #3b82f6;
            outline-offset: 4px;
            box-shadow: 0 0 0 6px rgba(59, 130, 246, 0.15), 0 25px 60px rgba(0, 0, 0, 0.15);
        }

        .upload-crop-panel {
            width: min(1080px, 100%);
            max-height: 92vh;
            background: #ffffff;
            border-radius: 16px;
            box-shadow: 0 25px 80px rgba(15, 23, 42, 0.4);
            border: 1px solid #e2e8f0;
            display: flex;
            flex-direction: column;
            overflow: hidden;
        }

        .upload-crop-stage {
            position: relative;
            height: min(68vh, 720px);
            background:
                linear-gradient(45deg, #f1f5f9 25%, transparent 25%),
                linear-gradient(-45deg, #f1f5f9 25%, transparent 25%),
                linear-gradient(45deg, transparent 75%, #f1f5f9 75%),
                linear-gradient(-45deg, transparent 75%, #f1f5f9 75%);
            background-size: 24px 24px;
            background-position: 0 0, 0 12px, 12px -12px, -12px 0px;
            overflow: hidden;
            user-select: none;
            cursor: grab;
            touch-action: none;
        }

        .upload-crop-stage.is-panning {
            cursor: grabbing;
        }

        .upload-crop-stage img {
            position: absolute;
            pointer-events: none;
            user-select: none;
            -webkit-user-drag: none;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
        }

        .upload-crop-viewport {
            position: absolute;
            left: 0;
            top: 0;
            transform-origin: top left;
            pointer-events: none;
        }

        .upload-crop-selection {
            position: absolute;
            border: 2px solid #2563eb;
            box-shadow: 0 0 0 9999px rgba(15, 23, 42, 0.45);
            cursor: grab;
            touch-action: none;
            pointer-events: none;
        }

        .upload-crop-handle {
            position: absolute;
            width: 14px;
            height: 14px;
            background: #ffffff;
            border: 2px solid #2563eb;
            border-radius: 9999px;
            z-index: var(--z-modal-handle);
            pointer-events: auto;
            touch-action: none;
        }

        .upload-crop-handle.nw {
            left: -8px;
            top: -8px;
            cursor: nwse-resize;
        }

        .upload-crop-handle.ne {
            right: -8px;
            top: -8px;
            cursor: nesw-resize;
        }

        .upload-crop-handle.sw {
            left: -8px;
            bottom: -8px;
            cursor: nesw-resize;
        }

        .upload-crop-handle.se {
            right: -8px;
            bottom: -8px;
            cursor: nwse-resize;
        }
        .cart-steps-modal {
            position: fixed;
            inset: 0;
            z-index: var(--z-modal-cart);
            background: rgba(15, 23, 42, 0.74);
            display: none;
            align-items: center;
            justify-content: center;
            padding: 1.25rem;
        }

        .cart-steps-modal.is-open {
            display: flex;
        }

        .cart-steps-panel {
            width: min(980px, 100%);
            max-height: 92vh;
            background: #fff;
            border-radius: 18px;
            border: 1px solid #e2e8f0;
            box-shadow: 0 26px 80px rgba(2, 6, 23, 0.45);
            overflow: hidden;
            display: flex;
            flex-direction: column;
        }

        .checkout-steps {
            display: flex;
            gap: 1rem;
            align-items: center;
            padding: 0.9rem 1.2rem;
            border-bottom: 1px solid #e2e8f0;
            background: #f8fafc;
        }

        .checkout-step {
            display: flex;
            align-items: center;
            gap: 0.55rem;
            color: #64748b;
            font-size: 0.9rem;
            font-weight: 600;
        }

        .checkout-step-dot {
            width: 1.6rem;
            height: 1.6rem;
            border-radius: 9999px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            border: 1px solid #cbd5e1;
            background: #fff;
            color: #64748b;
            font-size: 0.78rem;
            font-weight: 700;
        }

        .checkout-step.active {
            color: #0f172a;
        }

        .checkout-step.active .checkout-step-dot {
            background: #111827;
            color: #fff;
            border-color: #111827;
        }

        .checkout-step.done .checkout-step-dot {
            background: #16a34a;
            color: #fff;
            border-color: #16a34a;
        }

        .checkout-step-separator {
            flex: 1;
            height: 1px;
            background: #dbe4ef;
            min-width: 30px;
        }

        .cart-step-content {
            padding: 1.25rem;
            overflow-y: auto;
        }

        .cart-step-pane {
            display: none;
        }

        .cart-step-pane.active {
            display: block;
        }

        .cart-design-preview {
            width: 100%;
            max-height: 52vh;
            object-fit: contain;
            border-radius: 12px;
            background: repeating-conic-gradient(#f8fafc 0% 25%, #eef2f7 0% 50%) 50% / 24px 24px;
            border: 1px solid #dbe3ee;
        }

        .cart-base-grid {
            display: grid;
            grid-template-columns: repeat(3, minmax(0, 1fr));
            gap: 0.75rem;
        }

        .cart-base-card {
            border: 1px solid #dbe3ee;
            border-radius: 12px;
            background: #fff;
            padding: 0.75rem;
            cursor: pointer;
            transition: border-color .15s ease, box-shadow .15s ease;
        }

        .cart-base-card.selected {
            border-color: #111827;
            box-shadow: 0 0 0 2px rgba(17, 24, 39, 0.08);
        }

        .cart-base-card img {
            width: 100%;
            aspect-ratio: 16 / 10;
            object-fit: cover;
            border-radius: 8px;
            border: 1px solid #e2e8f0;
            margin-bottom: 0.6rem;
        }

        @media (max-width: 768px) {
            .upload-crop-panel {
                max-height: 96vh;
            }

            .upload-crop-stage {
                height: 56vh;
            }

            .checkout-steps {
                gap: 0.5rem;
                padding: 0.8rem;
            }

            .checkout-step {
                font-size: 0.78rem;
            }

            .cart-base-grid {
                grid-template-columns: repeat(2, minmax(0, 1fr));
            }
        }

        @media (max-width: 520px) {
            .cart-base-grid {
                grid-template-columns: 1fr;
            }
        }

        #cart-steps-next {
            background: #111827;
            color: #ffffff;
        }

        #cart-steps-next:hover {
            background: #1f2937;
        }