Accessibility
Accessibility statement — WCAG 2.2 AA target and feedback.
Chemistry Fundamentals targets WCAG 2.2 Level AA for all public pages and essential interactions. We treat automated tooling as one input — not proof of conformance — and review with keyboard-only, zoom/reflow, light/dark/forced-colors/reduced-motion, and semantic inspection across representative templates and interactive tools.
Our commitment
Chemistry should be learnable without barriers. We design for keyboard, screen reader, low-vision, cognitive, and situational needs — one meaningful H1 per page, logical heading levels, proper landmarks (header, nav, main, footer, search, form), a skip link to #main-content, descriptive titles and language attributes, and breadcrumbs as an ordered list with aria-current="page".
What we support
- Keyboard and focus: every control is reachable by keyboard with visible, high-contrast focus indicators in both themes; no traps except correctly-managed modal focus containment (Escape / close returns focus); Tab order follows visual order; no positive tabindex; custom widgets follow ARIA patterns; drag has keyboard/button alternative.
- Zoom and reflow: browser text zoom and 200% zoom retain all content/functionality; layout reflows at 320 CSS pixels without two-dimensional page scrolling except genuine data tables/periodic structures that offer an accessible list alternative; we do not lock viewport scaling; touch targets are ~44×44 px; sticky regions do not cover focused elements.
- Color and themes: text and UI contrast meets AA; correctness/trend states use text/icons as well as color; light, dark, and system themes keep code, equations, tables, borders, and form states legible; forced-colors remains usable; we avoid legibility-reducing gradients.
- Chemistry and data: subscripts, superscripts, charges, isotopes, arrows, states, and units render visually correctly with accessible text; KaTeX outputs HTML + MathML; tables use
captionandscope; large tables provide filter/list alternatives; periodic trends include summaries and nonvisual data access; decorative diagrams use emptyalt. - Forms and feedback: every control has a persistent programmatic label; required state and formats are conveyed before submission; errors identify the field, problem, and correction via
aria-describedbywithout clearing valid input; status uses text/icons as well as color; live regions are concise; calculation inputs use matchinginputmode/autocomplete/units. - Motion and cognition: we respect
prefers-reduced-motion; no rapid flashing; simulations have pause/reset and textual values; no autoplay audio/video; instructions use plain language and do not depend on color/location alone; timing is optional or extendable.
Known exceptions
The interactive periodic table’s main grid is scrollable horizontally at narrow widths, with a synchronized list/alternative filter view and visible overflow cues. Where a table truly requires two-dimensional scrolling, an accessible filtered/faceted alternative is provided. If you encounter a page where focus, zoom, or screen-reader announcement is unclear, please report it — especially for calculator error messages, filter state, or periodic-table trend descriptions.
Compatibility
Tested with modern browsers, keyboard-only navigation, browser zoom/reflow, light/dark/forced-colors/reduced-motion, and semantic/screen-reader spot checks. Core lessons and navigation remain available without JavaScript; interactive tools (calculators, periodic table, search palette) degrade gracefully with a clear non-JS message.
Feedback
If you encounter a barrier, please contact us or use Feedback. Include the URL, your browser/assistive technology, and what you expected. Safety-critical or calculation errors are treated with the process at Corrections. We review reports promptly and publish fixes transparently.
Details
Last updated: 2026-08-23.