.d-none 
{
    display : none; 
}

.d-block 
{
    display : block;
}

.d-flex 
{
    display : flex; 
}

.d-flex.flex-direction-col
{
    flex-direction: column;
}

.d-flex.flex-direction-row
{
    flex-direction: row;
}

.d-flex.flex-content-around 
{
    justify-content: space-around; 
}

.d-flex.flex-content-between
{
    justify-content: space-between;
}

.d-flex.flex-content-center
{
    justify-content: center;
}

.d-flex.flex-content-end
{
    justify-content: end;
}

.d-flex.flex-content-even
{
    justify-content: space-evenly;
}

.d-flex.flex-content-start
{
    justify-content: start;
}

.d-flex.flex-align-items-start 
{
    align-items: flex-start;
}

.d-flex.flex-align-items-end 
{
    align-items: flex-end;
}

.d-flex.flex-align-items-center 
{
    align-items: center;
}