Navigation and controls
Use the skip link to reach the main content. The navigation menu supports keyboard operation and Escape to close and return focus. Form fields have text labels, visible focus and messages associated with their inputs.
Calculations and reading
Interactive calculators require JavaScript. Concepts, formulas, worked examples, and FAQs remain readable without it. Supplementary technical notes use native disclosure controls; the main educational content stays expanded.
Display preferences
The layout adapts to narrow screens, keeps text labels with controls and respects reduced-motion preferences. Complex result tables keep their column labels when displayed as records on smaller screens.
Scope
Accessibility is an ongoing consideration, not a claim of certification. Browser, assistive-technology and display combinations can differ. If an interactive tool is unavailable, its formula and worked example provide an alternative way to review the method.