A card back, in the style of [mid-century modern], featuring [abstract shapes], [bold colors], [mint green], and [stylized atomic symbols]. drawn all the way to the edges with no background visible. the card back should have a unique design, with elements of symmetry and repetition, flat with no shadow, no script, horizontal symmetry, while still maintaining a cohesive look and feel. the overall design should evoke a sense of [mod sophistication], playfulness, and [atomic age glamour], the final product should be high-quality, vector artwork, suitable for printing on the backs of standard playing cards.