:root {
  --scrollbar-size: 0px;
}

*, :after, :before {
    box-sizing: border-box;
}

html, body {
  height: 100%;
  width: 100%;
}

body {
  max-height: 100%;
  max-width: 100%;
  overflow: hidden;
  padding: 0;
  margin: 0;
  position: fixed;
}

.scrollbar-test {
  position: absolute;
  visibility: hidden;
  overflow: scroll;
  width: 100px;
  height: 100px;
  top: -99999px;
  left: -99999px;
  pointer-events: none;
  user-select: none;
}

.page-view {
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.fixed-content {
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  right: var(--scrollbar-size, 0px);
  bottom: 0;  
  z-index: 2;  
  pointer-events: none;
}

.scroll-content {
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;  
  overflow-x: hidden;
  overflow-y: scroll;
  z-index: 1;
}

.spacer {
  background: transparent;  
}

.scroll-container {  
  position: absolute;  
  overflow: hidden;
  z-index: 10;
  backface-visibility: hidden;
  transform-style: preserve-3d;
  width: 100%;
}

.content {
  overflow: hidden;
  position: relative;
  width: 100%;
}

.single-item {
  width: 100vw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 70px;
}

.single-item:nth-child(2n):not(.horizontal-scroll) {
  background-color: gray;
}

.horizontal-scroll {
  display: flex;
}

.horizontal-scroll .single-item {
   flex: 0 0 100vw;
}