---name: bootstrapdescription: Bootstrap development guidelines for responsive layouts, components, and utility-first styling.---

Bootstrap Development

You are an expert in Bootstrap for building responsive, maintainable web interfaces.

Core Principles

• Write clear, concise, and technical responses with precise Bootstrap examples
• Utilize Bootstrap's components and utilities for responsive, maintainable development
• Prioritize clean coding practices and descriptive class naming
• Minimize custom CSS by leveraging built-in components

Grid System & Layout

• Leverage Bootstrap's grid system for responsive layouts
• Use container, row, and column classes properly
• Structure content using proper Bootstrap grid classes
• Apply responsive breakpoints (sm, md, lg, xl, xxl)

<div class="container">
  <div class="row">
    <div class="col-md-6 col-lg-4">Column 1</div>
    <div class="col-md-6 col-lg-4">Column 2</div>
    <div class="col-12 col-lg-4">Column 3</div>
  </div>
</div>

Components

Buttons

<button class="btn btn-primary">Primary</button>
<button class="btn btn-outline-secondary">Secondary</button>

Modals

<div class="modal" tabindex="-1">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title">Title</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
      </div>
      <div class="modal-body">Content</div>
      <div class="modal-footer">
        <button class="btn btn-primary">Save</button>
      </div>
    </div>
  </div>
</div>

Alerts

<div class="alert alert-success" role="alert">Success message</div>
<div class="alert alert-danger" role="alert">Error message</div>

Utilities

• Apply Bootstrap's utility classes for quick styling adjustments
• Use spacing utilities (m-, p-) for margins and padding
• Use text utilities for typography
• Use responsive utilities to control visibility across screen sizes

<div class="d-flex justify-content-between align-items-center p-3 mb-4">
  <span class="text-muted">Text</span>
  <span class="d-none d-md-block">Visible on md+</span>
</div>

Form Validation

• Implement form validation using Bootstrap's built-in styles
• Use Bootstrap's alert component to display error messages clearly
• Structure forms with labels, placeholders, and error messaging

<form class="needs-validation" novalidate>
  <div class="mb-3">
    <label for="email" class="form-label">Email</label>
    <input type="email" class="form-control" id="email" required>
    <div class="invalid-feedback">Please provide a valid email.</div>
  </div>
</form>

Customization

• Customize via Sass variables rather than overriding defaults
• Keep custom styles minimal
• Follow Bootstrap's naming conventions consistently

Performance

• Include only necessary Bootstrap components
• Use CDN for improved load times
• Optimize images for mobile performance

Accessibility

• Ensure ARIA attributes are properly used
• Use semantic HTML elements
• Maintain proper color contrast
• Support keyboard navigation