Use Custom Rendering Styles for Entity References, Comments, or PIs

There is a built-in CSS stylesheet in the Oxygen XML Editor libraries that is used when styling content in the Author mode, no matter what CSS you use. This CSS has the following content:

@namespace oxy url('http://www.oxygenxml.com/extensions/author');
@namespace xi "http://www.w3.org/2001/XInclude";
@namespace xlink "http://www.w3.org/1999/xlink";
@namespace svg "http://www.w3.org/2000/svg";
@namespace mml "http://www.w3.org/1998/Math/MathML";

oxy|document {
    display:block !important;
}

oxy|cdata {
    display:morph !important;
    white-space:pre-wrap !important;
    border-width:0px !important;
    margin:0px !important;
    padding: 0px !important;
}

oxy|processing-instruction {
    display:block !important;
    color: rgb(139, 38, 201) !important;
    white-space:pre-wrap !important;
    border-width:0px !important;
    margin:0px !important;
    padding: 0px !important;
}

oxy|comment {
    display:morph !important;
    color: rgb(0, 100, 0) !important;
    background-color:rgb(255, 255, 210) !important;
    white-space:pre-wrap !important;
    border-width:0px !important;
    margin:0px !important;
    padding: 0px !important;
}

oxy|reference:before,
oxy|entity[href]:before{  
  link: attr(href) !important;
  text-decoration: underline !important;
  color: navy !important;
  
  margin: 2px !important;
  padding: 0px !important;  
}

oxy|reference:before {
  display: morph !important;
  content: url(../images/editContent.gif) !important;  
}

oxy|entity[href]:before{
  display: morph !important;
  content: url(../images/editContent.gif) !important;
}

oxy|reference,
oxy|entity {
    editable:false !important;
    background-color: rgb(240, 240, 240) !important;
    margin:0px !important;
    padding: 0px !important;
}

oxy|reference {
    display:morph !important;
}

oxy|entity {
    display:morph !important;
}

oxy|entity[href] {
  border: 1px solid rgb(175, 175, 175) !important;
  padding: 0.2em !important;
}

xi|include {
    display:block !important;
    margin-bottom: 0.5em !important;
    padding: 2px !important;
}
xi|include:before,
xi|include:after{
    display:inline !important;
    background-color:inherit !important;
    color:#444444 !important;
    font-weight:bold !important;
}

xi|include:before {
    content:url(../images/link.gif) attr(href)  !important;
    link: attr(href) !important;
}
xi|include[xpointer]:before {
    content:url(../images/link.gif) attr(href) " " attr(xpointer) !important;
    link: oxy_concat(attr(href), "#", attr(xpointer)) !important;
}

xi|fallback {
    display:morph !important;
    margin: 2px !important;
    border: 1px solid #CB0039 !important;
}

xi|fallback:before {
    display:morph !important;
    content:"XInclude fallback: " !important;
    color:#CB0039 !important;
}

oxy|doctype {
    display:block !important;
    background-color: transparent !important;
    color:blue !important;
    border-width:0px !important;
    margin:0px !important;
    padding: 2px !important;
}

oxy|error {
    display:morph !important;
    editable:false !important;
    white-space:pre !important;
    color: rgb(178, 0, 0) !important;
    font-weight:bold !important;
}

*[xlink|href]:before {
    content:url(../images/link.gif);
    link: attr(xlink|href) !important;
}

/*No direct display of the MathML and SVG images.*/
svg|svg{
    display:inline !important;
    white-space: trim-when-ws-only;
}
svg|svg svg|*{
    display:none !important;
    white-space:normal;
}

mml|math{
    display:inline !important;
    white-space: trim-when-ws-only;
}
mml|math mml|*{
    display:none !important;
    white-space: normal;
}

In the CSS used for rendering the XML in Author mode, do the following:

1. Import the special Author mode namespace.
2. Use a special selector to customize the entity node.

Example:

@namespace oxy url('http://www.oxygenxml.com/extensions/author');
oxy|entity {
   background-color: inherit !important;
   margin:0px !important;
   padding: 0px !important;
    -oxy-display-tags:none;
}