Ниже приведена шпаргалка по Bootstrap, популярной CSS-инфраструктуре, с примерами кода для различных методов:

1. Система сетки:

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

2. Типографика:

   <h1 class="display-4">Heading</h1>
   <p class="lead">Lead paragraph</p>
   <p>Regular paragraph</p>

3. Кнопки:

   <button type="button" class="btn btn-primary">Primary</button>
   <a href="#" class="btn btn-secondary">Secondary</a>

4. Формы:

   <form>
    <div class="form-group">
      <label for="exampleFormControlInput1">Email address</label>
      <input type="email" class="form-control" id="exampleFormControlInput1" placeholder="name@example.com">
    </div>
    <div class="form-group">
      <label for="exampleFormControlTextarea1">Example textarea</label>
      <textarea class="form-control" id="exampleFormControlTextarea1" rows="3"></textarea>
    </div>
   </form>

5. Панель навигации:

   <nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#">Logo</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav">
        <li class="nav-item">
          <a class="nav-link" href="#">Link 1</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link 2</a>
        </li>
      </ul>
    </div>
   </nav>

6. Карточки:

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

7. Оповещения:

   <div class="alert alert-success" role="alert">
    This is a success alert.
   </div>

8. Модальные окна:

   <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">
    Launch Modal
   </button>
   
   <div class="modal fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-content">
        <div class="modal-header">
          <h5 class="modal-title" id="exampleModalLabel">Modal Title</h5>
          <button type="button" class="close" data-dismiss="modal" aria-label="Close">
            <span aria-hidden="true">&times;</span>
          </button>
        </div>
        <div class="modal-body">
          Modal content goes here.
        </div>
        <div class="modal-footer">
          <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
          <button type="button" class="btn btn-primary">Save changes</button>
        </div>
      </div>
    </div>
   </div>

9. Карусель:

   <div id="myCarousel" class="carousel slide" data-ride="carousel">
    <ol class="carousel-indicators">
      <li data-target="#myCarousel" data-slide-to="0" class="active"></li>
      <li data-target="#myCarousel" data-slide-to="1"></li>
      <li data-target="#myCarousel" data-slide-to="2"></li>
    </ol>
    <div class="carousel-inner">
      <div class="carousel-item active">
        <img src="slide1.jpg" class="d-block w-100" alt="Slide 1">
      </div>
      <div class="carousel-item">
        <img src="slide2.jpg" class="d-block w-100" alt="Slide 2">
      </div>
      <div class="carousel-item">
        <img src="slide3.jpg" class="d-block w-100" alt="Slide 3">
      </div>
    </div>
    <a class="carousel-control-prev" href="#myCarousel" role="button" data-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="sr-only">Previous</span>
    </a>
    <a class="carousel-control-next" href="#myCarousel" role="button" data-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="sr-only">Next</span>
    </a>
   </div>

10. Значки:

    <span class="badge badge-primary">Primary</span>
    <span class="badge badge-secondary">Secondary</span>

В этой шпаргалке представлены примеры кода для различных компонентов Bootstrap, таких как система сеток, типографика, кнопки, формы, панель навигации, карточки, оповещения, модальные окна, карусель и значки.