GeoServer CSS Styling variable

Question

May I set variable in CSS, like as

<ogc:Function name="env">

I have this:

* {
  fill: [recode(strTrim(name),
         'Akmola Region', '#6495ED',
         'Aktobe Region', '#B0C4DE')];
  fill-opacity:0.4;
  stroke: lightgrey;
}

but I want set variables for Fill and Stroke-width parameters. Like this:

<Rule>
          <Title>Akmola Region</Title>
           <ogc:Filter>
            <ogc:PropertyIsEqualTo>
             <ogc:PropertyName>name</ogc:PropertyName>
             <ogc:Literal>Akmola Region</ogc:Literal>
            </ogc:PropertyIsEqualTo>
          </ogc:Filter>
            <PolygonSymbolizer>
                  <Fill>                 
                  <CssParameter name="fill">
                  #<ogc:Function name="env">
                 <ogc:Literal>Akmola_fill_color</ogc:Literal> 
                   <ogc:Literal>6495ED</ogc:Literal>  
                  </ogc:Function>                   
                   </CssParameter>
                  <CssParameter name="fill-opacity">0.4</CssParameter>
                  </Fill>
              <Stroke>
                <CssParameter name="stroke">#605f5f</CssParameter>
                <CssParameter name="stroke-width">
                <ogc:Function name="env">
                <ogc:Literal>Akmola_stroke_width</ogc:Literal>
                <ogc:Literal>0.1</ogc:Literal> 
                </ogc:Function>
                </CssParameter>                 
              </Stroke>
          </PolygonSymbolizer>
        </Rule>

        <Rule>
          <Title>Aktobe Region</Title>
           <ogc:Filter>
            <ogc:PropertyIsEqualTo>
             <ogc:PropertyName>name</ogc:PropertyName>
             <ogc:Literal>Aktobe Region</ogc:Literal>
            </ogc:PropertyIsEqualTo>
          </ogc:Filter>
            <PolygonSymbolizer>
                  <Fill>
                  <CssParameter name="fill">
                  #<ogc:Function name="env">
                 <ogc:Literal>Aktobe_fill_color</ogc:Literal> 
                   <ogc:Literal>B0C4DE</ogc:Literal>  
                  </ogc:Function>                   
                   </CssParameter>
                    <CssParameter name="fill-opacity">0.4</CssParameter>
                  </Fill>
              <Stroke>
                <CssParameter name="stroke">#605f5f</CssParameter>
                <CssParameter name="stroke-width">
                <ogc:Function name="env">
                <ogc:Literal>Aktobe_stroke_width</ogc:Literal>
                <ogc:Literal>0.1</ogc:Literal> 
                </ogc:Function>
                </CssParameter>                 
              </Stroke>
          </PolygonSymbolizer>
        </Rule>

I want emulate hover event when mouse hover on map object. Maybe it is possible with css capabilities?

Answer 1

   * {
      fill: [recode(strTrim(name),
             'Akmola Region', env('color_Akmola','#6495ED'),
             'Aktobe Region', env('color_Aktobe','#B0C4DE'))];
      fill-opacity:0.4;
      stroke: lightgrey;
    }
    /* &env=color_Akmola:%23ff0000 */