stepped-scroll.css

:root {
  --duration: 0.5s;
}
.scrollable {
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
  overflow: hidden !important;
  padding: 0 !important;
}
.scrollable .scroll {
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
  display: inline-block;
  width: 99%;
  height: 0;
  -webkit-transform: translateY(100%);
      -ms-transform: translateY(100%);
          transform: translateY(100%);
  opacity: 0;
  -webkit-transition: opacity var(--duration), -webkit-transform var(--duration);
  transition: opacity var(--duration), -webkit-transform var(--duration);
  -o-transition: transform var(--duration), opacity var(--duration);
  transition: transform var(--duration), opacity var(--duration);
  transition: transform var(--duration), opacity var(--duration), -webkit-transform var(--duration);
}
.scrollable .scroll.current {
  -webkit-transform: translateY(0) !important;
      -ms-transform: translateY(0) !important;
          transform: translateY(0) !important;
  opacity: 1;
  height: 100%;
  max-height: 100vh;
  overflow: hidden;
  -webkit-transition: opacity var(--duration) 0.1s, -webkit-transform var(--duration) 0.1s;
  transition: opacity var(--duration) 0.1s, -webkit-transform var(--duration) 0.1s;
  -o-transition: transform var(--duration) 0.1s, opacity var(--duration) 0.1s;
  transition: transform var(--duration) 0.1s, opacity var(--duration) 0.1s;
  transition: transform var(--duration) 0.1s, opacity var(--duration) 0.1s, -webkit-transform var(--duration) 0.1s;
}
.scrollable .scroll.current:not(.unactivable) {
  position: relative;
}
.scrollable .scroll.current:not(.unactivable).active {
  max-height: 100%;
  overflow: auto;
}
.scrollable .scroll.current:not(.unactivable).active .close-active-post {
  z-index: 10;
}
.scrollable .scroll.prev {
  -webkit-transform: translateY(-100%);
      -ms-transform: translateY(-100%);
          transform: translateY(-100%);
}
.scrollable.gpu-render .scroll {
  -webkit-transform: translateZ(0);
          transform: translateZ(0);
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  -webkit-perspective: 1000;
          perspective: 1000;
}