How this site is built to be read

The standard we are aiming at

The Web Content Accessibility Guidelines 2.2, level AA. We are claiming an aim, not a certification: this is a self-assessment by the people who built the site, and it has not been audited by anyone else.

What is built in

Specifically, and all of it verifiable by inspecting the page:

• A skip link, first in the tab order, that jumps past the navigation to the main content
• One visible focus style everywhere — a two-pixel outline in the brand blue, offset three pixels, on anything you can reach with a keyboard
• Real landmarks: a single main region, a navigation region, a footer, and headings in order
• The menu button reports its own open state, and the current section is marked in the navigation, so a screen reader announces where you are
• Every technical drawing carries a text description of the argument it is making, not just a label naming it
• Decorative marks are hidden from assistive technology rather than read out as noise
• The page is declared as English, so screen readers pronounce it correctly
• It works with JavaScript switched off — the drawings render finished and every link works

Colour and contrast

Both themes were designed on their own terms rather than one being an inversion of the other, and every text colour was checked against the surface it sits on. Body text measures 14.5:1 on the light theme and 15.4:1 on the dark one. The blue used for links and actions measures 6.5:1 and 7.2:1. AA asks for 4.5:1.

Colour is never the only way information is carried. In the case-file drawings, the before and after paths are distinguished by position, label and line style as well as by red and blue.

Motion

This site animates a good deal: drawings that draw themselves as you scroll, a figure that pins while a narrative steps through it, and eased scrolling on a mouse wheel.

All of it is decorative and all of it is switched off by your system's “reduce motion” setting. With that on, every animation and transition is disabled, the wheel scrolls normally, and the drawings render in their finished state. Nothing is hidden behind an animation, so nothing is lost by turning it off.

What we know is not done

Stating this plainly is more useful to you than a conformance badge:

• No independent accessibility audit has been carried out, and no testing with assistive-technology users. Everything above is our own assessment
• The stepped read of the case-file drawing is a visual device. The same information is in the text beside it and in the drawing's description, but the highlighting itself is not announced
• Some of the technical drawings are dense, and their text alternatives summarise the argument rather than describing every element
• Third-party pages we link to are outside our control and may not meet this standard

Telling us we have got something wrong

Email the address in the footer. Tell us the page, what you were trying to do, and what your browser and assistive technology are if you know. You will get a person, not an autoresponder, and we aim to reply within one business day.

If something is blocking you from getting information you need, say so and we will send it to you in a format that works while we fix the page.