d-block bg-dark text-white

html bootstrap5 Sample

背景に色を付ける：bg-primary

bg-primary

bg-secondary

bg-success

bg-danger

bg-warning

bg-info

bg-light

bg-dark

bg-white

bg-transparent

  <div class="text-center">
    <p><a href="#" class="bg-primary text-white d-block py-2">bg-primary</a></p>
    <p><a href="#" class="bg-secondary text-white d-block py-2">bg-secondary</a></p>
    <p><a href="#" class="bg-success text-white d-block py-2">bg-success</a></p>
    <p><a href="#" class="bg-danger text-white d-block py-2">bg-danger</a></p>
    <p><a href="#" class="bg-warning text-dark d-block py-2">bg-warning</a></p>
    <p><a href="#" class="bg-info text-white d-block py-2">bg-info</a></p>
    <p><a href="#" class="bg-light text-dark d-block py-2">bg-light</a></p>
    <p><a href="#" class="bg-dark text-white d-block py-2">bg-dark</a></p>
    <p><a href="#" class="bg-white text-dark d-block py-2">bg-white</a></p>
    <p><a href="#" class="bg-transparent d-block py-2">bg-transparent</a></p>
  </div>

ブロック表示のspan：d-block

ブロック表示のspan ブロック表示のspan 
  <span class="d-block bg-primary text-white">ブロック表示のspan</span>
  <span class="d-block bg-dark text-white">ブロック表示のspan</span>