Instruction file imported from miguelslemos/stock_portfolio (.cursor/rules/ui-presentation.mdc). Copyright stays with the author.

UI and Presentation

Professional Look with Low Complexity

• Clean, professional appearance using pure CSS (no CSS framework)
• CSS variables for colors, shadows, and spacing (already defined in styles.css)
• Inter font as the typographic standard
• Responsive layout with native grid/flexbox

Component Reuse

• Use Builders for complex HTML (ModalBuilder, YearDetailsBuilder)
• Extract repeated visual patterns into reusable functions/builders
• Never duplicate markup — if a pattern appears 2+ times, create a builder

// ❌ Bad: duplicated HTML
const card1 = `<div class="card"><h3>${title1}</h3>...</div>`;
const card2 = `<div class="card"><h3>${title2}</h3>...</div>`;

// ✅ Good: reusable builder
const card1 = CardBuilder.create(title1).withContent(...).build();
const card2 = CardBuilder.create(title2).withContent(...).build();

Presentation vs Domain Separation

• Formatters (BRLFormatter, USDFormatter) belong in presentation/
• Never put calculation logic in builders or UI controllers
• PortfolioApp coordinates the UI but delegates logic to use cases
• Data arrives at the presentation layer already processed — just format and display

CSS

• Use existing CSS variables (--color-*, --shadow-*, --radius-*)
• Avoid inline styles — use classes
• Maintain a single styles.css file organized by section