bootstrap4.css
@media (min-width: 576px) {
.modal-dialog {
max-width: 500px;
margin: 1.75rem auto;
}
.modal-dialog-scrollable {
max-height: calc(100% - 3.5rem);
}
.modal-dialog-scrollable .modal-content {
max-height: calc(100vh - 3.5rem);
}
.modal-dialog-centered {
min-height: calc(100% - 3.5rem);
}
.modal-dialog-centered::before {
height: calc(100vh - 3.5rem);
}
.modal-sm {
max-width: 300px;
}
}
■モーダル:modal:小さなサイズのモーダル modal-sm
<!-- 切替ボタン -->
<button type="button" class="btn btn-secondary" data-toggle="modal" data-target="#smallModal">モーダルボタン(modal-sm)</button>
<!-- モーダル -->
<div class="modal fade" id="smallModal" tabindex="-1" role="dialog" aria-labelledby="smallModalLabel" aria-hidden="true">
<!-- モーダルのダイアログ本体 -->
<div class="modal-dialog modal-sm" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="smallModalLabel">モーダルのタイトル</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
</div>
<div class="modal-body">モーダルの本文が入ります。</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">閉じる</button>
</div>
</div>
</div>
</div>