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bootstrap-components

Guides proper usage of Bootstrap 4.5.2 components (navbar, cards, buttons, modals, forms). Use when

作者 yennanliu|オープンソース

Bootstrap Component Usage

Navbar Configuration

  • Use Bootstrap navbar for responsive navigation
  • Mobile hamburger menu with collapse
  • Sticky or fixed positioning for persistent navigation
  • Dark/light variants for theming

Example structure:

<nav class="navbar navbar-expand-lg navbar-dark bg-dark fixed-top">
  <a class="navbar-brand" href="#">Brand</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav ml-auto">
      <li class="nav-item"><a class="nav-link" href="#">Home</a></li>
    </ul>
  </div>
</nav>

Card Components

  • Bootstrap card for uniform layouts
  • Combines well with grid for responsive galleries
  • Use card-deck for equal-height cards
  • Custom footer for CTA buttons

Example:

<div class="card">
  <img class="card-img-top" src="image.jpg" alt="Card image">
  <div class="card-body">
    <h5 class="card-title">Card Title</h5>
    <p class="card-text">Description text</p>
    <a href="#" class="btn btn-primary">Learn More</a>
  </div>
</div>

Button Styling

  • Use Bootstrap button classes: btn, btn-primary, btn-secondary
  • Size variants: btn-sm, btn-lg
  • State management: active, disabled, loading states
  • Custom hover colors with CSS variables

Form Components

  • Use Bootstrap form groups
  • Validation states (is-valid, is-invalid)
  • Floating labels for modern UI
  • Accessible input types and labels

Example:

<form>
  <div class="form-group">
    <label for="email">Email address</label>
    <input type="email" class="form-control" id="email" placeholder="name@example.com">
  </div>
  <button type="submit" class="btn btn-primary">Submit</button>
</form>

Grid System

  • 12-column Bootstrap grid
  • Responsive classes: col-xs, col-sm, col-md, col-lg, col-xl
  • Utilities: gutter spacing, alignment
  • Nesting for complex layouts

Example:

<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-md-12 col-lg-4">Column 3</div>
  </div>
</div>

Modal Components

  • Use Bootstrap modals for overlays
  • Fade animation for smooth transitions
  • Centered or scrollable variants
  • Proper accessibility (aria-labelledby, aria-hidden)

Custom Bootstrap Overrides

  • Override Bootstrap variables before importing
  • Use CSS variables for runtime theming
  • Add custom classes alongside Bootstrap classes
  • Avoid !important - use more specific selectors instead
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