• —On your first visit you can choose the Classic version: a calm, single-page site with no 3D, smooth scrolling or motion effects. You can switch at any time from the menu or footer.
• —Every page works with a keyboard alone, with visible focus indicators and a “skip to content” link.
• —Semantic headings, landmarks and labels, so screen readers can navigate the structure.
• —The 3D “Space” on the home page has a plain list alternative — the Index view — with the same links.
• —Charts include text descriptions, and every number shown in an animation is also available as text.
• —If your system asks for reduced motion, smooth scrolling, 3D scenes and scroll animations are turned off.
• —Text colours meet WCAG AA contrast against their backgrounds.
• —Form fields have labels, clear error messages that are announced to screen readers, and no time limits.

The 3D scenes are decorative and are hidden from assistive technology; all of their content is available elsewhere on the page. Some very dense diagrams are best viewed on a larger screen, and each has a text summary.

If anything on this site is hard to use, please tell me at y.gerber00@gmail.com and I’ll fix it.