If you just want the HTML authored in CKEditor to look the same inside your page, first you must insert it inside a div element with a custom class, for example, "my-container".
Then you have to include contents.css in your page. Here you have to alternatives: 1) use Scoped Stylesheets or 2) modify contents.css, scoping each rule.
1. Using Scoped Stylesheets
In this case you should use Scoped Stylesheets and JQuery Scoped CSS plugin (due to current lack of browser support).
Your HTML code would look like this:
<div class="my-container">
<style scoped>
@import "ckeditor/contents.css";
</style>
<!-- Your HTML goes here -->
</div>
2. Scoping each rule inside contents.css
In this case you must link to a modified copy of CKEditor's contents.css file. Each of the rule's selector must be scoped to "my-container" class, so it doesn't affect the rest of the page. Example contents.css file:
.my-container
{
/* Font */
font-family: sans-serif, Arial, Verdana, "Trebuchet MS";
font-size: 12px;
/* Text color */
color: #333;
/* Remove the background color to make it transparent */
background-color: #fff;
margin: 20px;
}
.my-container .cke_editable
{
font-size: 13px;
line-height: 1.6em;
}
.my-container blockquote
{
font-style: italic;
font-family: Georgia, Times, "Times New Roman", serif;
padding: 2px 0;
border-style: solid;
border-color: #ccc;
border-width: 0;
}
.my-container .cke_contents_ltr blockquote
{
padding-left: 20px;
padding-right: 8px;
border-left-width: 5px;
}
.my-container .cke_contents_rtl blockquote
{
padding-left: 8px;
padding-right: 20px;
border-right-width: 5px;
}
.my-container a
{
color: #0782C1;
}
.my-container ol,.my-container ul,.my-container dl
{
/* IE7: reset rtl list margin. (#7334) */
*margin-right: 0px;
/* preserved spaces for list items with text direction other than the list. (#6249,#8049)*/
padding: 0 40px;
}
.my-container h1,.my-container h2,.my-container h3,.my-container h4,.my-container h5,.my-container h6
{
font-weight: normal;
line-height: 1.2em;
}
.my-container hr
{
border: 0px;
border-top: 1px solid #ccc;
}
.my-container img.right
{
border: 1px solid #ccc;
float: right;
margin-left: 15px;
padding: 5px;
}
.my-container img.left
{
border: 1px solid #ccc;
float: left;
margin-right: 15px;
padding: 5px;
}
.my-container pre
{
white-space: pre-wrap; /* CSS 2.1 */
word-wrap: break-word; /* IE7 */
}
.my-container .marker
{
background-color: Yellow;
}
.my-container span[lang]
{
font-style: italic;
}
.my-container figure
{
text-align: center;
border: solid 1px #ccc;
border-radius: 2px;
background: rgba(0,0,0,0.05);
padding: 10px;
margin: 10px 20px;
display: block; /* For IE8 */
}
.my-container figure figcaption
{
text-align: center;
display: block; /* For IE8 */
}