I have no legend setting on the axis tab.
I see a expression axis setting and a Dimension setting.
both of them are set as i need but still the font size is not changed.
the total that showing on top of the chart is coming from the expression label.
I think this could be set by scripting but i don't know how to do it.
the expression is Sum(Sales), and as i leave the label blank, it shows the total nr as label.
I think you want to display like this, if so.
Try - Properties - Axes - Expression Axes - Font - Font Style , Size , color as you want apply and apply it .
If you don't want to display the values at top of the expression.
Properties - Expression - Values on Data Points (Remove Mark on it).
Hope it helps