vibrant banner with pumpkins, fall leaves, and sunflowers for a joyful seasonal celebration.

autumn thanksgiving background pumpkin leaf festive banner seasonal colorful warm joyful shiny flower colors fall composition glittering nature greeting october november halloween vegetable celebration foliage plant sunflower rustic beautiful yellow border card decoration holiday orange squash floral light season flare natural vibrant bokeh cheerful garden traditional pumpkins leaves sunflowers generative celebration