Built into the design
Text and surface pairs come from one semantic token system, and inverted panels (hero bands, the footer, proof sheets) reference theme-stable tokens so a dark panel stays dark in the dark theme instead of inverting into pale-on-pale text. Contrast for every shipped token pair is computed against the WCAG relative-luminance formula rather than eyeballed, including the translucent edges that tell you a rectangle is fillable — those are composited over the surface they sit on before the ratio is measured, because a hairline border is only ever seen through its background. Interactive surfaces carry their own `--control-edge` token for that reason instead of borrowing the decorative hairline. Every custom property the sheets read is also checked for a declaration: a token that is used but never set is discarded at computed-value time, which is how a theme ends up painting inherited colours in only one mode, and no build step notices.
Every interactive control has a visible focus state, primary and mobile navigation regions are separately labelled, exactly one `main` landmark is rendered per page, and a skip link lands on the content region. The mobile drawer traps focus, closes on Escape, and is marked inert while closed so its links leave the tab order.
Motion is opt-out: the pointer-reactive tilt and parallax layers disable under `prefers-reduced-motion` and can be forced off in workspace preferences. Nothing on the site communicates state with color alone — freshness, verification, and publication states are labelled in words.