Generate a simple, flat 'X' icon for closing menus or dialog boxes in a user interface. The 'X' should consist of two intersecting, bold lines with rounded or slightly tapered ends. The design should be centered on a vibrant red circular or square background to indicate a close or cancel action. The style should be clean, symmetrical, and modern, optimized for small screen sizes. Avoid extra details, shadows, or gradients to maintain a flat, minimalistic aesthetic Voir plus