.responsive-container {
      max-width: 1200px;
      width: 90%;
      margin: 0 auto;
      padding: 2rem;
      background: #000000
      box-sizing: border-box;
      font-size: 1rem;
    }
.responsive-block {
  font-size: 1rem;
  padding: 1em;
  margin-bottom: 1.5rem;
}
    
    .responsive-content {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 20px;
    }
    
    .responsive-item {
      background: white;
      padding: 1rem;
      border-radius: 8px;
      box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    }
    
    @media (max-width: 600px) {
      .responsive-container {
        padding: 1rem;
      }
    }
/*
<div class="responsive-container">
    <div class="responsive-content">
      <div class="responsive-item">Элемент 1</div>
      <div class="responsive-item">Элемент 2</div>
      <div class="responsive-item">Элемент 3</div>
    </div>
  </div>
*/