Horizontally and vertically center bootstrap 4 columns in consecutive rows
问题 I'm trying to simply center justify and align two bootstrap columns inside a container. The columns are in different rows. The grid layout is <body style="height: 100vh;"> <div class="container"> <div class="row"> <div class="col-6"> <div class="card"> hello </div> </div> </div> <div class="row"> <div class="col-4"> <div class="card"> world </div> </div> </div> </div> </body> the cards are just to outline the containers. I'm aware there are MANY questions on vertical alignment, and I may have