Минималистичный Инженерный Эскиз Продукта

An engineering-style product design sketch of [a minimalist smart gadget], featuring delicate, precise technical line art on a pure white background with generous negative space. Includes a dark gray handwritten title, concise technical icons, and precise engineering annotation callouts explaining step-by-step details. Accented with subtle, highly transparent watercolor washes in light blue, light green, and light orange. Modern, clean, and tech-savvy aesthetic reminiscent of Apple and Tesla design ideation sheets.