Ok so I've got this submenu in the sidebar, but I run into an issue when it comes to animating it. I have tried to use the transform property in combination with display: none;, but still it opens instantly. If I use only transform, it takes up the space… Is there any way around this, with transform or without it?
.hide-submenu {
    display: none;
    transform: scaleY(0);
}
.show-submenu {
    transform: scaleY(1);
}
Here's a Stackblitz example: https://stackblitz.com/edit/angular-bvk6ku?file=src%2Fapp%2Fapp.component.ts
