Full-frame minimalist squiggly line art of a steaming coffee cup with bold, playful steam lines rising upward. The words “Dad Fuel” should be subtly integrated into the steam or appear in a simple hand-drawn font above or within the cup. Design must use true black lines only on a white background. Keep the composition centered, balanced, and clean — no color, no shading. Capture a fun, energetic vibe suited for Father's Day coffee lovers.