Simple CSS for responsive layouts using Flexbox and CSS Grid in website design. The grid layout with dynamic columns adjusts to screen size using auto-fill and minmax(), offering flexible interface customization. Combined with media queries, it adapts to various device sizes (590px is an example value, replace it with the standard size of the device you’re targeting). If you’re developing a module, plugin, or website that requires high responsiveness across devices, Flexbox is a flexible and scalable choice for interface design.