a[globalhome] {
 bottom: calc(var(--global-spacing) / 2);
 left: calc(var(--global-spacing) / 2);
 width: 1.5em;
 height: 1.5em;
 filter: saturate(0) brightness(0.4);
 view-transition-name: globalhome;
 z-index: 10000;
 transition: opacity calc(1000ms * var(--speed)) ease;
}
#start.current ~ a[globalhome] { opacity: 0; }

::view-transition-group(root) {
 animation-duration: calc(200ms * var(--speed));
 animation-timing-function: ease;
}