div.icolset
.ibreak-s: forces 100% width .icol at screen smaller than 720px
.ibreak-m: forces 100% width .icol at screen smaller than 960px
.iwidth-xs: 480px max-width
.iwidth-s: 720px max-width
.iwidth-m: 960px max-width
.iwidth-l: 1200px max-width
div.icol
.iwidth-100: 100% width
.iwidth-66: 66.7% width (100% on smaller screen defined by .icolset.ibreak)
.iwidth-50: 50% width (100% on smaller screen defined by .icolset.ibreak)
.iwidth-100: 33.3% width (100% on smaller screen defined by .icolset.ibreak)