Avatar Illustration with Single-Line Doodle

Scene:
- 1:1 square format, suitable for social media avatar use
- Clean dark-toned background; automatically choose a calm deep color palette based on the overall color mood of the input image, such as deep blue, deep green, deep purple, dark brown, dark gray, burgundy, ink black, blue-gray, or dark olive
- Simple background with no scene, keeping only the subject and a few spontaneous accents
- Subject centered or slightly off-center, with safe empty space reserved for circular avatar cropping
Subject:
- Identify a person, cat, dog, other animal, or plant from the input image as the main avatar subject
- Extract the subject's most recognizable outer silhouette and key features, reconstructing them as a minimalist single-line avatar or character illustration
- For people, preserve key contours such as face shape, forehead, nose bridge, mouth transition, chin, ears, and hairstyle, keeping only a few essential facial features
- For animals, preserve the head shape, ears, muzzle outline, eye expression, and the broad flow of the fur; for plants, preserve the most recognizable forms from flowers, leaves, stems, fruit, or the overall posture
Important details:
- Lines should be smooth, rounded, open, expressive, and natural, as continuous as possible in one effortless stroke, with a sense of breath and spontaneity
- Use mostly soft curves, with few sharp, stiff, or rigid angular lines; avoid mechanically traced outlines
- Use thin white or soft warm-white lines for the main subject contour, creating clear contrast against the dark background; light and clear without becoming too thick
- Composition should be focused and eye-catching, with a complete subject silhouette and a clear visual center, still easy to recognize at small sizes
- Add a few small, random, natural colorful accents around the subject, such as tiny dots, small arcs, little stars, smiley faces, short strokes, small lightning bolts, or simple geometric symbols
- Accent elements should be rounded, playful, and relaxed, distributed with a slightly random feel, used sparingly and not overly symmetrical
- Accent colors should be lightly drawn from neighboring or complementary background colors, with subtle pops such as yellow, orange, pink, pale purple, or light coral
- Overall, create a minimalist, light, modern, lively single-line illustration style, combining the relaxed feel of spontaneous doodling with a collectible quality
Use case: Social media avatar
Constraints:
- No realism, shadows, light-and-dark volume, complex textures, or complex scenes
- No mechanical tracing, stiffness, harsh sharpness, or excessive regularity
- Do not fix the background color to a single blue template; keep the dark background selected according to the mood of the input image
- Do not make the background too bright, glaring, muddy gray, low-contrast, or lifeless
- Do not use too many or overly dense decorations, and do not let them overpower the subject; preserve the subject's spirit and recognizability