This plan addresses the refactoring, organization, and optimization of CSS with a focus on maintainability, scalability, and performance. Each step includes testing to ensure the UI remains consistent throughout the refactoring process.

• 1.1 Analyze current CSS structure
  • Identify all CSS files and their locations
  • Document current organization pattern (if any)
  • Identify duplicate styles and redundancies
  • Note browser compatibility issues
• 1.2 Create a visual inventory of UI components
  • Screenshot key UI components for reference
  • Document current styling patterns
• 1.3 Identify CSS performance issues
  • Check for overly specific selectors
  • Identify render-blocking CSS
  • Look for unused CSS

• 2.1 Choose a CSS methodology
  • BEM (Block Element Modifier)
  • SMACSS (Scalable and Modular Architecture for CSS)
  • ITCSS (Inverted Triangle CSS)
  • Atomic CSS
• 2.2 Create folder structure for CSS organization
  • src/styles/base/ (reset, typography, variables)
  • src/styles/components/ (buttons, forms, cards, etc.)
  • src/styles/layouts/ (grid, containers, header, footer)
  • src/styles/utilities/ (helper classes)
  • src/styles/themes/ (dark mode, custom themes)
• 2.3 Define CSS variables for design system
  • Colors
  • Typography (font families, sizes, weights)
  • Spacing (margins, paddings)
  • Breakpoints
  • Transitions
  • Z-indices

• 3.1 Create src/styles/base/reset.css
  • Implement CSS reset or normalize.css
  • Set box-sizing to border-box
  • Reset margins and paddings
• 3.2 Create src/styles/base/typography.css
  • Define font families
  • Set up heading styles
  • Define paragraph styles
  • Set up link styles
• 3.3 Create src/styles/base/variables.css
  • Define CSS custom properties (variables)
  • Organize by category (colors, spacing, etc.)
• 3.4 Test base styles for consistency

• 4.1 Create src/styles/layouts/grid.css
  • Define grid system or flexbox layouts
  • Create reusable layout patterns
• 4.2 Create src/styles/layouts/containers.css
  • Define container widths and constraints
  • Set up responsive containers
• 4.3 Create src/styles/layouts/header.css and footer.css
  • Move header-specific styles
  • Move footer-specific styles
• 4.4 Test layouts across different screen sizes

• 5.1 Identify all UI components
  • Buttons
  • Forms and inputs
  • Cards
  • Navigation elements
  • Modals/dialogs
  • Tables
  • etc.
• 5.2 Create individual component CSS files
  • One file per component type
  • Follow naming convention from chosen methodology
• 5.3 Move component styles from existing CSS
  • Refactor according to chosen methodology
  • Remove duplications
  • Simplify selectors
• 5.4 Test each component for visual consistency

• 6.1 Create src/styles/utilities/spacing.css
  • Margin and padding utility classes
• 6.2 Create src/styles/utilities/display.css
  • Visibility and display helpers
• 6.3 Create src/styles/utilities/flex.css
  • Flexbox helper classes
• 6.4 Create src/styles/utilities/text.css
  • Text alignment, transformation, etc.
• 6.5 Test utility classes for consistency

• 7.1 Define breakpoint strategy
  • Mobile-first or desktop-first
  • Breakpoint values
• 7.2 Refactor media queries
  • Consolidate duplicate media queries
  • Organize by component rather than breakpoint
• 7.3 Test responsive behavior
  • Mobile devices
  • Tablets
  • Desktops
  • Large screens

• 8.1 Remove unused CSS
  • Use tools like PurgeCSS or UnCSS
  • Manually remove obsolete styles
• 8.2 Minimize specificity issues
  • Reduce nesting
  • Simplify selectors
• 8.3 Optimize critical CSS
  • Identify above-the-fold styles
  • Consider inline critical CSS
• 8.4 Test performance improvements

• 9.1 Create src/styles/themes/
  • Light theme
  • Dark theme
  • Additional themes if needed
• 9.2 Implement theme switching mechanism
  • CSS custom properties
  • Class-based approach
• 9.3 Test theme switching

• 10.1 Create CSS style guide
  • Document naming conventions
  • Document CSS architecture
  • Document component styles
• 10.2 Create component library/pattern library
  • Visual examples of components
  • Usage guidelines
• 10.3 Document CSS best practices for the project

• Ensure all CSS files are properly organized in their respective folders
• Verify import order in main CSS file
• Check for any remaining inline styles in HTML/JSX
• Ensure all component-specific styles are in their own files
• Verify that global styles don't conflict with component styles

• Compare before/after screenshots of key pages
• Test all interactive states (hover, focus, active)
• Verify animations and transitions

• Chrome
• Firefox
• Safari
• Edge

• Mobile portrait (320px-375px)
• Mobile landscape
• Tablet portrait (768px)
• Tablet landscape
• Desktop (1024px+)
• Large desktop (1440px+)

• Color contrast meets WCAG standards
• Focus states are visible
• Text is readable at different sizes

• CSS file size before and after
• Page load time before and after
• Rendering performance (FPS during scrolling/animations)

• Specificity wars (overuse of !important)
• Overly complex selectors
• Duplicate styles across files
• Inconsistent naming conventions
• Media query duplication
• Unused CSS rules
• Hard-coded values instead of variables
• Non-responsive elements
• Z-index stacking context issues