Accessibility
Guidance for using the site and understanding the limitations of interactive activities.
Reading and navigation
Use the text button next to search to change text size, font, spacing and contrast as you browse. Your choices are remembered in the same browser when local storage is available. You can also use browser zoom. Navigate with Tab and Shift+Tab; Enter activates links. Game controls vary by activity.
Seasonal animations
Christmas and Easter decorations start automatically, even when reduced motion is enabled. Use “Pause animations” at the bottom left to stop them. Your choice is remembered in the same browser when local storage is available; “Resume animations” restarts them.
Limitations and feedback
This page is not an accessibility certification. Graphical games, diagrams and formulas may be difficult to use with some assistive technologies. To report a barrier, use the contact listed on the Privacy page, if available, and include the page, device, browser and problem.