I just want to tell how to add style sheet to the pages before some one ask how to do that..
1) Open the file '<EXO-HOME>\webapps\resources\WEB-INF\skin-config.xml'
2) Modify the content
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<portlet-style-config>
<portlet-name>default</portlet-name>
<style name="default" url="/resources/skin/portlet/default-portlet.css"/>
<style name="community" url="/resources/community/skin/community.css"/>
</portlet-style-config>
-----------------------------------------------
to -----------------------------------------------
<portlet-style-config>
<portlet-name>default</portlet-name>
<style name="default" url="/resources/skin/portlet/default-portlet.css"/>
<style name="community" url="/resources/community/skin/community.css"/>
<style name="mycompstyle" url="/MyCompPortlet/skin/mycomp-style.css"/>
</portlet-style-config>
-----------------------------------------------
Here 'MyCompPortlet' is context where the style sheet is available. For this you also should have a style sheet with name 'myComp-style.css' in the '<EXO-HOME>/webapps/MyCompPortlet/skin/' directory.
3) Restart the exo-tomcat then you will be able to see your style sheet in the edit properties mode of portlet as below...
