A crisp greybox / blueprint lo-fi wireframe — neutral grey blocks on a pale page, image placeholders drawn as a rectangle with a diagonal X, text shown as solid "lorem bars" of varying widths, sharp 1.5–2px borders, and a single monospace redline accent for annotations. Reads like a structural blueprint before any visual design is applied. Use when the brief asks for "greybox", "blueprint wireframe", "lo-fi dashboard", "low fidelity", "线框图", or "灰盒原型".