A Sass snippet to make bootstrap modals more mobile friendly by turning them into a 'bottom sheet' on smaller screens

mobile-friendly-bootstrap-modals-bottom-sheet.scss

.modal {
    display: flex;
    align-items: flex-end;

    &.fade {

        .modal-dialog-bottom {
            position: absolute;
            bottom: 0;
            transition: transform 0.4s;
            transform: translate(0, 100%);
            margin: 0 auto 0;
            left: 0;
            right: 0;
            max-height: 100vh;

            @media (min-width: 767.98px) {
                bottom: 50%;
                transform: translate(0, 50%);
            }

            .modal-content {
                overflow-y: visible;
                border-radius: 0;
            }
        }
    }

    &.show {
        .modal-dialog-bottom {
            transform: translate(0, 0);

            @media (min-width: 767.98px) {
                transform: translate(0, 50%);
            }
        }
    }
}