25 design guideline sets a founder without a designer can run. Nielsen's 86 rules, 17 interface states, 350 front-end checks.

An agent-built screen ships with one state. A real interface has seventeen, and a seven-field contract for each. Fewer than one in three clean sans-serifs pass two font checks. Print a logo in black first. 25 enumerated design sets, each one a checklist you can run tonight, with the source linked.