Font-size definition

Hello folks,

In my custom stylesheet I defined my own template for guilabel,  
guimenu, etc.

Sometimes I use those tags inside section title and I would like to a  
font-size proportional to the title font size.

I tried with font-size="0.9em" (in the fo:inline statement). It's ok  
for the titles, but it's to big for normal text. In this case it  
should be  proportional to $body.font.master.

The section font-size are already proportional to $body.font.master.

<xsl:template name="myGuiMenu">
         <xsl:param name="content">
             <xsl:apply-templates/>
         </xsl:param>
         <fo:inline xmlns:fo="http://www.w3.org/1999/XSL/Format" font- 
family="LucidaGrande" font-weight="normal" font-size="0.9em">
             <xsl:if test="@id">
                 <xsl:attribute name="id">
                     <xsl:value-of select="@id"/>
                 </xsl:attribute>
             </xsl:if>
             <xsl:if test="@dir">
                 <xsl:attribute name="direction">
                     <xsl:choose>
                         <xsl:when test="@dir = 'ltr' or @dir =  
'lro'">ltr</xsl:when>
                         <xsl:otherwise>rtl</xsl:otherwise>
                     </xsl:choose>
                 </xsl:attribute>
             </xsl:if>
             <xsl:copy-of select="$content"/>
         </fo:inline>
     </xsl:template>

How can I to that without define another template for the titles ?

Thanks in advance,
Jacques