Three checks
Fix the desk before you train the neck.
A perfect chin tuck loses to a laptop flat on the desk. Tick these once. Recapture baseline if you raise the screen after.
Screen at eye line
Top of the display near eye height. Laptop on a stand, keyboard on the desk. Looking down is the whole problem.
An arm’s length away
If you can rest a palm on the screen, you’re too close and you’ll crane. Brightness up so you don’t lean in.
Sit on your sit bones
Scoot back. Two bony points under you. Breastbone floating, ribs quiet, feet on the floor.