Multi-column drop down menu in Debut theme

Store Design
134
  1. Go to Online Store->Theme->Edit code
  2. Asset->theme.scss Or theme.css-> paste bellow code in bottom of file
#SiteNav > li:nth-child(2) .side-bar-menu{width:100%;}
#SiteNav > li:nth-child(2) .side-bar-menu ul{column-count: 4;}