button
{
    height: 5rem;
}

.flexContainer
{
    flex-wrap: wrap;
}

.flexItem 
{
    flex-basis: 50%;
    flex-shrink: 0;
    flex-grow: 0;
    padding: 1rem;    
}

.flexItem button
{
    padding-left: 2rem;
    padding-right: 2rem;
}

@media only all and (orientation: portrait)
{
    .flexItem
    {
        flex-basis: 100%;
    }
}