In Nicepage, you can change values by clicking and moving the mouse over the icons near the values in the Property Panel.

Modify Properties With Mouse

Modify values by dragging the mouse over the property icons, such as Top, Left, Right, Bottom, Width, Height, Letter Spacing, etc.

Modify Padding With Mouse Move

Like other values, you can change the Padding values by moving the mouse over the letter corresponding to the Padding side.

Distance Between Selected Elements

You can change the Distance between selected Elements in the Property Panel by entering the value or dragging the cursor on the icon.