Font size units are converted inconsistently (px to em)

Phenomenon

When applying font sizes in Chrome, the units (px, em, rem) may be converted inconsistently. Relative units may be converted to absolute units, or vice versa, making it difficult to maintain consistent sizing.

Reproduction example

1. Apply font size with em unit: font-size: 1.2em
2. Edit the text or apply other formatting
3. Observe the font-size value

Observed behavior

• Units may be converted: 1.2em becomes 19.2px
• Or units may be preserved
• Conversion is inconsistent
• Relative sizing is lost

Expected behavior

• Units should be preserved as specified
• Or conversion should be predictable
• Relative units should remain relative
• Behavior should be consistent

Browser Comparison

• Chrome/Edge: May convert units (this case)
• Firefox: Similar conversion behavior
• Safari: Unit handling varies

Notes and possible direction for workarounds

• Preserve original units explicitly
• Convert units only when necessary
• Document unit conversion behavior
• Consider using data attributes to store original units