* { box-sizing: border-box; }

/* FlipBook */

.flipbook-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  perspective: 2000px;
  height: 100vh;
}

.book {
  position: relative;
  display: flex;
  margin-left: 90vw;

  height: 100vh; /* Force vertical scaling */
  aspect-ratio: 2159 / 2794; /* Maintain US Letter shape */
  width: auto; /* Auto width based on height and aspect ratio */
  max-width: 100vw;

  pointer-events: none;
  transform-style: preserve-3d;
  transition: translate 1s;
  translate: calc(min(var(--c), 1) * 50%) -10vh; /* optional adjustment */
  rotate: 1 0 0 20deg;
}

/* Changes 8: fixed flipbook viewport when on large screen vs smal screens */
@media (min-width: 600px) {
  .book {
    margin-left: 60vw;
  }
}

@media (min-width: 1024px) {
  .book {
    margin-left: 20vw;
  }
}

@media (min-width: 1440px) {
  .book {
    margin-left: 0; /* center it on large screens */
  }
}

.page {
  /* PS: Don't go below thickness 0.5 or the pages might transpare */
  --thickness: 4;
  flex: none;
  display: flex;
  height: 100%;
  width: 100%;
  font-size: 2cqmin;
  /*1* allow pointer events on pages */
  pointer-events: all;
  user-select: none;
  transform-style: preserve-3d;
  transform-origin: left center;
  transition:
    transform 1s,
    rotate 1s ease-in calc((min(var(--i), var(--c)) - max(var(--i), var(--c))) * 50ms);
  translate: calc(var(--i) * -100%) 0px 0px;
  transform: translateZ( calc((var(--c) - var(--i) - 0.5) * calc(var(--thickness) * .23cqmin)));
  rotate: 0 1 0 calc(clamp(0, var(--c) - var(--i), 1) * -180deg);
}

.page object {
  width: 100%;
  height: 100%;
  display: block;
  border: none;
}

.page object,
.page img {
  pointer-events: none;
}

.front,
.back {
  position: relative;
  flex: none;
  height: 100%;
  width: 100%;
  backface-visibility: hidden;
  overflow: hidden;
  background-color: #f6f2f2;
  /* Fix backface visibility Firefox: */
  translate: 0px;
}

.back {
  translate: -100% 0;
  rotate: 0 1 0 180deg;
}


/* That's it. Your FlipBook customization styles: */

.book {
  counter-reset: page -1;
  & a {
    color: inherit;
  }
}

.page {
  box-shadow: 0em .5em 1em -.2em #00000020;
}

.front,
.back {
  display: flex;
  flex-flow: column wrap;
  justify-content: space-between;
  border: 1px solid #0002;
  
  &:has(img) {
    padding: 0;
  }
  
  & img {
    width: 100%;
    height: 100%;
    object-fit: cover;
  }
  
  &::after {
    position: absolute;
    bottom: 1em;
    counter-increment: page;
/*    content: counter(page) ".";*/
    font-size: 0.8em;
  }
}
.cover {
  &::after {
    content: "";
  }
}
.front {
  &::after {
    right: 1em;
  }
  background: linear-gradient(to left, #f7f7f7 80%, #eee 100%);
  border-radius: .1em .5em .5em .1em;
}
.back {
  &::after {
    left: 1em;
  }
  background-image: linear-gradient(to right, #f7f7f7 80%, #eee 100%);
  border-radius: .5em .1em .1em .5em;
}

.cover {
  background: radial-gradient(circle farthest-corner at 80% 20%, hsl(150 80% 20% / .3) 0%, hsl(170 60% 10% / .1) 100%),
    hsl(231, 32%, 29%) url("https://picsum.photos/id/984/800/900") 50% / cover;
  color: hsl(200 30% 98%);
}

.book,
.page {
  background: transparent !important;
  border: none !important;
  box-shadow: none !important;
}

.front,
.back {
  background-size: contain;
  background-position: center center;
  background-repeat: no-repeat;
  background-color: transparent;
  border: none !important;
  box-shadow: none !important;
}