@mixin large {
    @media (min-width: 940px) { @content; }
}  

@mixin small {
    @media (min-width: 460px) { @content; }
}

@mixin xlarge {
    @media (min-width: 1200px) { @content; }
}

@mixin large-max {
    @media (max-width: 940px) { @content; }
}

@mixin medium {
    @media (min-width: 720px) { @content; }
}

@mixin max-medium {
    @media (max-width: 939px) { @content; }
}

@mixin medium-max {
    @media (max-width: 720px) { @content; }
}