TAX REFUND wants the public pages to work with a keyboard, a screen reader, and a phone. Controls are labeled, the estimator result is announced as it updates, and color is not the only way status is shown.
This is not a certification and not an audit report. We have not hired a third party to certify conformance with WCAG.
If a page blocks you, use the contact form and describe the page and what you were trying to do. Do not include tax identifiers in that message. We will reply about the barrier, not about a return, unless you already have an engagement.