The rules

  1. Transitions

6. Transitions

<!-- transition: fade|slide|zoom|none --> sets how a slide arrives; the front matter transition: sets the default (fade).

When two consecutive slides show the same SVG file with svg:, the slide transition is replaced by the canvas transition: the picture stays put, its state animates, and the words around it fade in. See SVG canvases.

With prefers-reduced-motion: reduce every transition and animation is off.