Diagnosis
The standard white top has a laminate finish that's durable but can be stained by certain inks and harsh chemicals, which can dull or damage the surface.
How to Fix It
Start gentle. Dampen a soft microfiber cloth with just warm water and a tiny drop of mild dish soap. Wring it out well so it's barely damp, not wet. Gently rub the marked area. For stubborn marks like ballpoint pen, try a pencil eraser first—it often works on laminate. If that fails, use a very small amount of rubbing alcohol (isopropyl alcohol, 70% or less) on a cotton swab, dab (don't rub hard) at the mark, and immediately wipe the area with the damp soapy cloth to remove any alcohol residue.
If That Didn't Work
For set-in stains, a dedicated laminate floor cleaner or a paste of baking soda and water can be used. Apply the paste with a soft cloth in a circular motion, then wipe clean with a damp cloth. Always test any cleaner in an inconspicuous spot first, like under the desk near a corner.
Heads Up
Avoid all abrasive scrubbers, magic erasers (they're micro-abrasive), bleach, ammonia, or glass cleaners. They will permanently strip the finish and leave a cloudy, rough spot. For daily dust, a dry microfiber cloth is best.