Bounded motion specimen / local only

Draw the spring. Measure the gap.

Sample a declared underdamped step response into CSS linear() stops. Compare the piecewise reconstruction with the continuous target, then preview one 40-pixel panel entrance.

Boundary: This is a fixed timing-function approximation, not live spring physics. Fit error is progress error for this formula; it does not guarantee perceptual quality on another component.

Curve controls

Controls are finite and bounded. The emitted list includes both endpoints and preserves interior overshoot.

Fit receipt

Maximum progress error
RMS progress error
Target peak
Syntax support

Errors compare 1,001 points of the reference and emitted piecewise interpolation. At 40 pixels travel, multiply progress error by 40 to estimate pixel gap.

Continuous target and sampled trace

Continuous spring response and piecewise linear CSS approximationBlue line is the continuous target; coral line and dots are the sampled CSS stops. Exact numerical errors appear below and update with controls.continuous targetsampled linear()

Generated CSS

Component preview
Review request
Click during motion to retarget from the current position. Reduced motion settles immediately.
JP Casabianca · No dependencies or network calls · Verify real component size, focus, and interruption before shipping