Graffiti Sketch Style Guide

Expressing the [theme/subject] in a graffiti sketch style, presenting a visual effect of rapid sketching, free transformation, improvisational hand-drawing, and draft-like style. Lines are casual and exaggerated, varying in thickness, slightly messy but rhythmic and expressive, emphasizing generalization, exaggeration, playfulness, and spontaneity rather than rigid realism or detailed description. 

The color uses rough, dry-brushed blocks to retain uneven smears, brush marks, whitening, and coverage. Colors automatically adapt according to [theme/subject], but overall maintain doodle, sketch-like, and generalized expression. No transparent watercolor gradation effect, no delicate watercolor transitions, no paper textures, no soft matte effects, no dreamy textures. 

The background should mainly use blank space, maintaining simplicity, ease, unfinished design, and a sense of design. You can add a few auxiliary symbols, arrows, marks, circles, repeated lines, casual writing, or other doodle elements to enhance the visual language of a sketchbook or essay, but it should not be too crowded or disrupt the main subject and the quality of the blank space. 

The content does not need to be clearly written in advance; the [Theme/Subject] automatically deduces and generates the most suitable subject image, actions, related elements, symbols, or simplified scenes, maintaining a unified graffiti sketching style and exaggerated and summarized expression, avoiding complex realistic backgrounds and excessive decoration. 
The image should naturally include the exclusive signature "voxcat" as part of the image. The position should be low-key yet clear, suitable for the lower left, lower right, or near the title. The style should be consistent with the overall layout, such as the artwork's signature or design signature; The signature font should be exquisite, restrained, and sophisticated, not too large, not disrupt the main composition, and should not appear abrupt or cheap.