A walkthrough of creating a fake 3D stage effect using CSS perspective transforms and minimal JavaScript. The technique uses three layers (background, tilted stage plane, foreground), CSS custom properties, and a small JS function that computes perspective-correct widths for the background and foreground based on the stage's tilt angle and geometry. Key insights include using rotateX() on a rectangle to simulate a floor plane, anchoring the background to the stage's back edge, and compensating for the foreground's own 3D translation when calculating its width.
Table of contents
Build the Scene with Three LayersUse a Perspective Container to Create DepthKeep the Background Fixed and Let the Foreground MoveMatch the Background and Foreground Widths to the StageUse JavaScript to Keep the Widths AlignedA Few Practical NotesWrapping UpSort: