Buttons can include an optional leading icon to enhance meaning and visual appeal.
Icon size automatically adjusts based on button size: size100 (24px) for small/medium, size125 (32px) for large.
Secondary and tertiary buttons apply optical balance blend to icons for visual weight compensation.
Spacing between icon and text adjusts based on button size: tight (4px) for small, normal (8px) for medium/large.
Comparison showing buttons with and without icons for the same action.