alert alert-danger

bootstrap5.css

bootstrap5.css
.alert-danger {
  color: #842029;
  background-color: #f8d7da;
  border-color: #f5c2c7;
}
bootstrap5.css
.alert-danger .alert-link {
  color: #6a1a21;
}

html bootstrap5 Sample

アラートの背景色:alert-*


  <div class="alert alert-primary" role="alert">alert-primary</div>
  <div class="alert alert-secondary" role="alert">alert-secondary</div>
  <div class="alert alert-success" role="alert">alert-success</div>
  <div class="alert alert-danger" role="alert">alert-danger</div>
  <div class="alert alert-warning" role="alert">alert-warning</div>
  <div class="alert alert-info" role="alert">alert-info</div>
  <div class="alert alert-light" role="alert">alert-light</div>
  <div class="alert alert-dark" role="alert">alert-dark</div>