.container-sm { margin-right: auto; margin-left: auto } @media (max-width: 767px ) { } @media (min-width: 768px ) { .maxwidth-sm { max-width:750px; } .container-sm { width:750px; } } .container-md { margin-right: auto; margin-left: auto } @media (max-width: 767px ) { } @media (min-width: 768px ) { .maxwidth-md { max-width:750px; } .container-md { width:750px; } } @media (min-width: 992px ) { .maxwidth-md { max-width:992px; } .container-md { width: 992px; } }