💄 refactor(playground): migrate inline styles to TailwindCSS v3 classes

- Replace all inline style objects with TailwindCSS utility classes
- Convert Layout and Layout.Sider component styles to responsive classes
- Simplify conditional styling logic using template literals
- Maintain existing responsive design and functionality
- Improve code readability and maintainability

Changes include:
- Layout: height/background styles → h-full bg-transparent
- Sider: complex style object → conditional className with mobile/desktop variants
- Debug panel overlay: inline styles → utility classes (fixed, z-[1000], etc.)
- Remove redundant style props while preserving visual consistency

web/src/components/playground/FloatingButtons.js

@@ -80,7 +80,7 @@ const FloatingButtons = ({
               ? 'linear-gradient(to right, #e11d48, #be123c)'
               : 'linear-gradient(to right, #4f46e5, #6366f1)',
           }}
-          className="lg:hidden !rounded-full !p-0"
+          className="lg:hidden"
         />
       )}
     </>