📌 How to use:
• Choose a Preset Layout (1×1, 1×2, 2×1, 2×2, etc.) or create a Custom Layout
• Click any empty + panel to select a window type and set dimensions (in mm)
• Use ✏️ Draw Split to divide panels: draw on left/right edge for vertical split, top/bottom for horizontal
• Each panel calculates area & price automatically. View breakdown in the right sidebar
• Adjust overall frame size (W × H) and all panels scale proportionally