How this site is built to be used

What that means in practice

• Structure. Semantic header, navigation, main, sections, and footer; one descriptive H1 per page and headings in order, never skipped for appearance.
• Keyboard. Every function works with a keyboard alone, including the mobile menu, worksheet, print, the clear-confirmation dialog, and the optional form.
• Focus. A visible-on-focus skip link reaches main content, and focus indicators are conspicuous and never hidden beneath sticky content.
• Contrast and color. Text and controls meet AA contrast, and meaning never depends on color alone—evidence labels carry words as well as styling.
• Zoom and reflow. Text resizes to 200% and the layout reflows at 320 CSS pixels without two-dimensional scrolling.
• Targets and links. Tap targets are at least 24 by 24 pixels, primary actions about 44 by 44, and links describe their destination; PDF links identify the file type.
• Motion and user settings. Motion is limited to subtle state changes and respects reduced-motion, forced-colors, high-contrast, and dark-mode settings where supported.
• Images and diagrams. No image carries essential text that is missing from HTML; the connected-node motif is marked decorative wherever the same idea is stated beside it.
• Forms. Labels, instructions, errors, and status messages are exposed programmatically, and errors identify the field and the correction in text.

The worksheet specifically

The HTML Readiness Card is a local worksheet: one form with no network submission, a fieldset and legend for each numbered section and answer group, a programmatically associated label on every field and checkbox, generous writing areas that keep entered text through responsive reflow, and print and clear controls that are separated—with confirmation required before answers are cleared. Print output stays legible on US Letter without removing warnings or result choices.