.columns{


display:block;

box-sizing: border-box;
float:left;
display:inline-block;
//padding:0 5px;

&:first-child{
padding-left:0px;

}
&:last-child{
padding-right:0px;

}

&.span_12{
width:100%;

}

&.span_11{
width:100/12*11;

}
&.span_10{
width:percentage(1/12*10);

}
&.span_9{
width:percentage(1/12*9);

}
&.span_8{
width:percentage(1/12*8);

}
&.span_7{
width:percentage(1/12*7);

}

&.span_6{
width:percentage(1/12*6);

}
&.span_5{
width:percentage(1/12*5);

}
&.span_4{
width:percentage(1/12*4);

}
&.span_3{
width:percentage(1/12*3);

}
&.span_2{
width:percentage(1/12*2);

}

&.span_1{
width:percentage(1/12*1);

}


}