Question: how to make slider trough small and then big on hover

[heeeeeeeeeeh]

I have it set so that when i hover over trough it get bigger, but when i click it makes the slider move to where the mouse is which makes the trough small because mouse is no longer hovered over it. Is there a way to make it so that when mouse hovers over slider trough get bigger?

here's my current config:
#backlight-slider {
color: @main-fg;
background: @main-bg;
opacity: 1;
margin: 6px 0px 6px 0px;
padding-left: 6px;
padding-right: 6px;
}

#backlight-slider slider {
min-height: 21px;
min-width: 21px;
color: @wb-color;
}

#backlight-slider trough {
min-width: 15px;
min-height: 21px;
border-radius: 5px;
background-color: @wb-act-bg;
}

#backlight-slider trough:hover {
min-width: 215px;
min-height: 21px;
border-radius: 5px;
background-color: @wb-act-bg;
}

#backlight-slider highlight {
color: @wb-color;
border-radius: 5px;
background-color: @wb-act-fg;
}