Changing Styles Dynamically

const styles = window.getComputedStyle(element);
const zIndex = parseInt(styles.zIndex, 10);

Computed styles always return strings
Values might include units
To handle browser differences
All of the above
Computed style values should be parsed because they always return strings, may include units (like 'px', '%', etc.), and browsers might return values in different formats. Using parseInt() or parseFloat() helps convert these strings into numbers for calculations. For properties like z-index, parseInt is sufficient, while for dimensions or positions, parseFloat might be more appropriate to handle decimal values.