Create a humorous t-shirt graphic titled "Mind the Gap." The design features a stylized illustration of a London Underground sign, complete with its iconic circular shape and color scheme. A playful cartoon cat, characterized by exaggerated features and a whimsical expression, peeks out from behind the sign, as if it’s "minding the gap" between the sign and the ground. The text "Mind the Gap" should be displayed in a bold, sans-serif font, centrally placed across the chest, with a subtle distressed effect to evoke a vintage feel. Utilize digital illustration techniques to create bold lines and playful textures, incorporating a bright and cheerful color palette. In post-production, apply subtle drop shadows and highlights to enhance depth and dimension, ensuring the final design maintains a transparent background for versatile printing options. This design is perfect for those who appreciate a lighthearted take on a classic British phrase.