Animate the overflow property
问题 I need to animate height, and set overflow: hidden for the first keyframe, and overflow: visible (and keep it) for the last one. I'm trying this, but at the end, overflow is still hidden . How can I solve this issue? The 2 includes are merely SCSS polifill mixins. @include keyframes(open) { 0% { height: 0; overflow: hidden; } 100% { height: $main_menu_height; overflow: visible; } } #main-menu-box { overflow: hidden; height: 0; &.opened{ @include animation('open 200ms ease-out 0s 1 normal