I'll create a Google sign-in button component for you using React and the shadcn/ui library. This button will follow Google's branding guidelines and be fully accessible.

This implementation creates a Google sign-in button that follows Google's branding guidelines:

1. The button uses Google's official logo.
2. The text "Sign in with Google" is used, which is one of Google's recommended button labels.
3. The button has a white background with a subtle outline, matching Google's design.
4. On hover, the button background changes slightly, providing visual feedback.
5. The button is fully responsive and will look good on various screen sizes.

The button is also accessible:

1. It uses semantic HTML (a button element).
2. The SVG icon is marked as aria-hidden="true" to prevent screen readers from announcing it.
3. The button text clearly describes the action ("Sign in with Google").

To use this button, you would typically add an onClick handler that initiates the Google Sign-In process. The exact implementation of this would depend on the authentication library or service you're using (such as Firebase Auth, Google Identity Services, or a custom OAuth implementation).

Remember to set up the necessary Google Sign-In API credentials and include any required scripts or libraries for Google authentication to work properly in your application.