Hello,  Sorry, if I understand you correctly, you can use bodyCls of the LayoutConfig... 1. UniHTMLFrame -> LayoutConfig -> bodyCls = myframe 2 CustomCSS: .myframe { height: 100%; margin: 0; background-repeat: no-repeat; background-attachment: fixed; background-image: linear-gradient(#E2FFA3, #C5DE8E); max-height: 100%; top: 100px; position: static; font-family: "helvetica"; }