A simple hand-drawn vintage illustration of an elegant birthday cake on a light gray-green background, in the style of mid-century modern design. The cake is white, the details'colors should be soft pastel shades of pink and purple with green accents. Use gentle lines to depict details like flowers and candles on top of each tier of the cake. Ensure that all elements fit within the borders of the card. This illustration create a beautiful and simplistic happy birthday greeting for friend, in the style of Henri Matisse and Mary Blair --ar 2:3