.display-4 { font-size: 3.5rem; font-weight: 300; line-height: 1.2; }
<h3>h3(標準)</h3> <!-- 高さも変わる、h1よりさらに大きく --> <h3 class="display-1">h3.display-1</h3> <h3 class="display-2">h3.display-2</h3> <h3 class="display-3">h3.display-3</h3> <h3 class="display-4">h3.display-4</h3>