custom grid

gistfile1.css

/* ===== Primary Styles =====================================================
    Author: Fruitcake Studio (Barry vd. Heuvel)
========================================================================== */
//Generate a custom (semantic) grid
.customGrid(@gridColumnWidth, @gridGutterWidth){   
    #header, #main {  
        .row();     
    }
    
    .block {
        .span(3);
    }   
    
    #content{
        .span(9);
    }
    
    footer {
        #copyright {
            .span(12);
        }
    }
    
    .thumbnails > li {
        .span(3);
    } 
    
    
    /* ===== Custom grid mixins =================================================
        Do not change this mixin below this line!
    ========================================================================== */
    .row()  when( isnumber(@gridColumnWidth) ) {
        margin-left: @gridGutterWidth * -1;
        .clearfix();
    }
    .row() when(@gridColumnWidth = auto){    
        margin-left: 0;
    }
    .span(@columns: 1, @offset: 0) when( isnumber(@gridColumnWidth) ) {
        float: left;
        margin-left: (@gridColumnWidth * @offset) + (@gridGutterWidth * (@offset - 1)) + (@gridGutterWidth * 2);
        width: (@gridColumnWidth * @columns) + (@gridGutterWidth * (@columns - 1));
        min-height: 1px; // prevent collapsing columns
    }
    .span (@columns, @offset: 0) when(@gridColumnWidth = auto){ 
        float: none;
        display: block;
        width: 100%;
        margin-left: 0;
        .box-sizing(border-box); 
    }   
}  

// Custom grid (default size)
.customGrid(@gridColumnWidth, @gridGutterWidth);

Left out the two troublesome lines… sorry about that:

.customGrid(@gridColumnWidth768, @gridGutterWidth768);

and

.customGrid(@gridColumnWidth1200, @gridGutterWidth1200);