@view-transition

navigation

Specifies the effect this at-rule will have on the document's view transition behavior. Possible values are:

• auto: The document will undergo a view transition when taking part in a navigation, provided the navigation is same-origin, without cross-origin redirects, and its navigationType is traverse, push, or replace. In the case of push or replace, the navigation must be initiated by a user interacting with the page content, not by a browser UI feature.
• none: The document will not undergo a view transition.

@view-transition = 
  @view-transition { <declaration-list> }  

The following code snippets show key concepts used in a page transition demo. The demo uses cross-document view-transitions; a half second transition that occurs when navigating between two pages of a site. For the full demo, see the View transitions multi-page app demo.

The @view-transition at-rule is specified in the CSS for both your current and destination documents of a navigation to opt them both in to the view transition:

@view-transition {
  navigation: auto;
}

In addition to the @view-transition at-rule, we define two @keyframe animations and use the animation shorthand property to apply those keyframe animations to the elements in the outbound (::view-transition-old()) and inbound (::view-transition-new()) pages that we want to animate.

/* Create a custom animation */
@keyframes move-out {
  from {
    transform: translateY(0%);
  }

  to {
    transform: translateY(-100%);
  }
}

@keyframes move-in {
  from {
    transform: translateY(100%);
  }

  to {
    transform: translateY(0%);
  }
}

/* Apply the custom animation to the old and new page states */
::view-transition-old(root) {
  animation: 0.4s ease-in both move-out;
}

::view-transition-new(root) {
  animation: 0.4s ease-in both move-in;
}

• View Transitions API