User Login Interface Upgrade in woocommerce

My website’s authentication flow works, but the screens that greet users during login and logout feel dated and clunky. I need a focused functionality update that refreshes these interfaces without touching the underlying session logic or database schema.

What I want:
• A modern, responsive UI for the existing login, logout, password-reset and registration views that matches my brand colours and typography.
• Clear error and success states, friendly micro-copy and accessible labels (WCAG-compliant).
• Smooth transitions between states (e.g., loading spinners, password visibility toggle) using lightweight JavaScript or the framework you recommend.
• Code written cleanly in HTML/CSS/JS (the site currently uses plain PHP templates, so no heavy frameworks are required, though I’m open to React/Vue if you can integrate them quickly).

Acceptance criteria:
1. Pages render correctly on Chrome, Firefox, Safari and Edge, from mobile up to 4K desktop.
2. No change to existing authentication endpoints; back-end continues to work exactly as before.
3. All static assets and snippets are delivered in a structured folder along with a short read-me so I can drop them straight into production.

Right now I only need this login/logout polish, but if the collaboration goes smoothly I may extend the work to other areas such as e-commerce checkout or general form submissions later.