I have created a Sandbox solution which contains two modules: one for Master page and other for Site Assets (js, css and images).
I have used background-image: url("")
in my style sheet file to add image to my dives. When I deploy the sandbox solution my dev environment it works great but on SharePoint Online none of the background-image:url("")
works at all.
Here is one of elements in my css file:
#page-wrapper {
background: url("/_catalogs/masterpage/munters/assets/UI/Images/backgrounds/site-bg.gif") repeat-x left top rgb(255, 255, 255); padding-top: 22px; padding-bottom: 50px; border-bottom-color: rgb(222, 222, 222); border-bottom-width: 1px; border-bottom-style: solid; min-width: 985px;
}