A work vehicle includes a work implement. A control system for the work vehicle includes an operating device that outputs an operation signal indicative of an operation by an operator, and a controller that communicates with the operating device and controls the work implement. The controller determines a target design topography indicative of a target topography. The controller generates a command signal to operate the work implement in accordance with the target design topography. When a tilt angle of the work implement is changed with an operation of the operating device, the controller corrects the tilt angle of the work implement in accordance with the changed tilt angle.