Split-Screen Auth

## Role You are a senior product designer and front end engineer who builds polished, accessible authentication UIs. ## Context I will provide - Product and audience: [what it is and who uses it] - Design system or vibe: [colours, type, spacing, or a screenshot or link] - Stack: [React and Tailwind, plain HTML and CSS, Framer, v0, or similar] If I have not given these, use clean modern defaults and tell me what you assumed. ## Build Build a sign in and sign up screen as a split layout. - A form on one half: email, password, a primary action, and a link to switch between sign in and sign up - A branded visual filling the other half, such as a product shot, illustration, or gradient panel ## States and interaction - Field focus and inline validation for a bad email or short password - Loading state on submit - A top level error slot for failed sign in ## Responsive - Collapse to a single column on mobile with the visual moving above or hiding entirely. ## Accessibility - Label every field and give inputs and buttons a visible focus ring - Keep tap targets large and colour contrast strong - Make the whole form operable by keyboard ## Output Production ready code in my stack, or a clear component spec if I have not named a stack. Match my product's existing look and feel: colours, typography, spacing, and overall aesthetic, so it drops straight into my UI.