nexus-ui-ux

name	nexus-ui-ux
description	UI/UX development guidelines using TailwindCSS, Shadcn UI, and Lucide icons. Use this skill when designing interfaces, fixing layout bugs, implementing dark mode, or handling extension-specific UI injection.

Project Nexus: UI & UX Engineering Protocol

1. Component Library (Shadcn UI)

• Rule of Thumb: Never build a base component from scratch if a Shadcn UI equivalent exists (e.g., Button, Input, Card, Dialog, Popover, Sheet, Skeleton).
• Class Merging: Always use the cn() utility function (combining clsx and tailwind-merge, typically located in lib/utils.ts) when applying dynamic Tailwind classes. This prevents CSS specificity conflicts.

2. Styling & Theming (TailwindCSS)

• Semantic Colors: Strictly use the CSS variables defined in the globals.css theme (e.g., bg-background, text-primary, border-border, bg-muted). Do not use hardcoded color scales (like bg-blue-500 or text-gray-700) unless it is a specific, unthemed accent.
• Dark Mode Support: The entire application must support dark mode seamlessly. Rely on semantic variables so colors flip automatically. If explicit overrides are needed, use the dark: variant.
• Responsive Design: Build mobile-first. Default classes apply to mobile screens. Use md:, lg:, and xl: for desktop layouts. Ensure the Web Dashboard's split-screen (List Feed + Visual Graph) collapses gracefully into a tabbed view or drawer on mobile devices.

3. Browser Extension UI Specifics (Plasmo)

• Style Isolation (Shadow DOM): Extension UI injected into host web pages (Content Scripts) MUST be rendered inside a Shadow DOM. This is critical. It prevents the host website's CSS from bleeding into our widget, and prevents our Tailwind classes from breaking the host site.
• Z-Index Management: For the floating "Capture" widget or slide-out summary drawer, use an extreme z-index (e.g., z-[999999]) so it never gets hidden behind the host website's sticky headers or modals.

4. Animations & Interactions

• Spaced Repetition UI: The flashcard review interface should feel tactile. Use CSS transforms (group-hover, scale) or framer-motion for smooth card flipping and swiping interactions.
• State Feedback: Every interactive element must have defined hover:, focus:, and disabled: states. Disabled buttons should explicitly use opacity-50 cursor-not-allowed.

5. UI Debugging Protocol

• Symptom: A newly added Tailwind class isn't applying at all.
  • Action: Verify the file's path is included in the content array of tailwind.config.ts.
• Symptom: The extension UI looks completely broken on certain websites (like Twitter or YouTube).
  • Action: Confirm that Plasmo is configured to inject the compiled Tailwind CSS file directly into the Shadow Root of the content script, not the global document.head.
• Symptom: Shadcn components look unstyled.
  • Action: Ensure globals.css is imported at the highest level (layout.tsx for Next.js, or the root Plasmo component).