Try Bootstrap 4's "grid only" CSS file. I used to do Flexbox by hand, until I realized I was reinventing the Bootstrap wheel by abstracting most of it into clas

Try Bootstrap 4's "grid only" CSS file. I used to do Flexbox by hand, until I realized I was reinventing the Bootstrap wheel by abstracting most of it into classes. It's all based on rows and columns, that collapse based on screen width. Plus, utility classes for all the alignment positions. You'll still run into the issue of way too many nested div's, but I find myself more productive than trying to flexbox everything by hand. ymmv.