.umpce-pdf-flipbook {
  display:block;
  width: 100%;
  margin: 12px auto;
  user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  outline: none;
}

.umpce-pdf-stage {
  width: 100%;
  background: #0b1220;
  border-radius: 14px;
  overflow: hidden;
  position: relative;
  box-shadow: 0 18px 40px rgba(0,0,0,0.25);
}

.umpce-pdf-sheet {
  position: relative;
  width: 100%;
  height: 100%;
}

.umpce-pdf-page {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  -webkit-user-drag: none;
  user-drag: none;
}

.umpce-pdf-page-front { z-index: 2; }
.umpce-pdf-page-back  { z-index: 1; }

/* ------------------------------------------------------------
   Desktop: Realistic-ish 3D page curl (best-effort)
   ------------------------------------------------------------ */
.umpce-pdf-sheet.umpce-mode-curl {
  perspective: 1900px;
}

.umpce-pdf-sheet.umpce-mode-curl .umpce-pdf-page {
  backface-visibility: visible;
  -webkit-backface-visibility: visible;
}

.umpce-pdf-sheet.umpce-mode-curl .umpce-pdf-page-back {
  transform: none !important;
}

.umpce-pdf-sheet.umpce-mode-curl .umpce-pdf-page-front {
  transform: translateZ(0);
  transform-origin: 100% 50%;
  transition: transform 0.9s cubic-bezier(0.19, 1, 0.22, 1);
  will-change: transform;
}

/* Shadows/highlights during curl */
.umpce-pdf-sheet.umpce-mode-curl::before,
.umpce-pdf-sheet.umpce-mode-curl::after{
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0;
  pointer-events: none;
  z-index: 3;
  transition: opacity 0.9s cubic-bezier(0.19, 1, 0.22, 1);
}

.umpce-pdf-sheet.umpce-mode-curl.is-next::before {
  opacity: 1;
  background: linear-gradient(90deg, rgba(0,0,0,0.55), rgba(0,0,0,0) 38%);
}

.umpce-pdf-sheet.umpce-mode-curl.is-prev::before {
  opacity: 1;
  background: linear-gradient(270deg, rgba(0,0,0,0.55), rgba(0,0,0,0) 38%);
}

.umpce-pdf-sheet.umpce-mode-curl.is-next::after {
  opacity: 1;
  background: linear-gradient(90deg, rgba(255,255,255,0.18), rgba(255,255,255,0) 22%);
}

.umpce-pdf-sheet.umpce-mode-curl.is-prev::after {
  opacity: 1;
  background: linear-gradient(270deg, rgba(255,255,255,0.18), rgba(255,255,255,0) 22%);
}

.umpce-pdf-sheet.umpce-mode-curl.is-next .umpce-pdf-page-front {
  transform-origin: 100% 50%;
  transform: rotateY(-125deg) rotateZ(-1deg) translateX(-2%);
  filter: drop-shadow(0 20px 25px rgba(0,0,0,0.35));
}

.umpce-pdf-sheet.umpce-mode-curl.is-prev .umpce-pdf-page-front {
  transform-origin: 0% 50%;
  transform: rotateY(125deg) rotateZ(1deg) translateX(2%);
  filter: drop-shadow(0 20px 25px rgba(0,0,0,0.35));
}

/* ------------------------------------------------------------
   Desktop: Card flip (used for last-page transitions)
   ------------------------------------------------------------ */
.umpce-pdf-sheet.umpce-mode-card {
  transform-style: preserve-3d;
  perspective: 1400px;
  transition: transform 0.65s ease;
}

.umpce-pdf-sheet.umpce-mode-card .umpce-pdf-page {
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.umpce-pdf-sheet.umpce-mode-card .umpce-pdf-page-back {
  transform: rotateY(180deg);
}

.umpce-pdf-sheet.umpce-mode-card.is-next {
  transform: rotateY(-180deg);
}

.umpce-pdf-sheet.umpce-mode-card.is-prev {
  transform: rotateY(180deg);
}

/* ------------------------------------------------------------
   Mobile: Slide (push)
   ------------------------------------------------------------ */
.umpce-pdf-sheet.umpce-mode-slide {
  overflow: hidden;
}

.umpce-pdf-sheet.umpce-mode-slide .umpce-pdf-page {
  backface-visibility: visible;
  -webkit-backface-visibility: visible;
  transition: transform 0.35s ease;
  will-change: transform;
}

.umpce-pdf-sheet.umpce-mode-slide .umpce-pdf-page-front {
  transform: translateX(0);
}

.umpce-pdf-sheet.umpce-mode-slide .umpce-pdf-page-back {
  transform: translateX(100%);
}

.umpce-pdf-sheet.umpce-mode-slide.is-next .umpce-pdf-page-front {
  transform: translateX(-100%);
}

.umpce-pdf-sheet.umpce-mode-slide.is-next .umpce-pdf-page-back {
  transform: translateX(0);
}

.umpce-pdf-sheet.umpce-mode-slide.is-prev .umpce-pdf-page-front {
  transform: translateX(100%);
}

.umpce-pdf-sheet.umpce-mode-slide.is-prev .umpce-pdf-page-back {
  transform: translateX(0);
}

/* ------------------------------------------------------------
   Controls
   ------------------------------------------------------------ */
.umpce-pdf-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  padding: 10px 6px 0;
}

.umpce-pdf-btn {
  border: 1px solid rgba(0,0,0,0.15);
  background: #ffffff;
  color: #111827;
  border-radius: 12px;
  padding: 8px 12px;
  font-size: 14px;
  cursor: pointer;
}

.umpce-pdf-btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.umpce-pdf-counter {
  font-size: 14px;
  color: #111827;
}

@media (max-width: 520px) {
  .umpce-pdf-controls {
    flex-wrap: wrap;
    justify-content: center;
  }
}


.umpce-pdf-flipbook, .umpce-pdf-flipbook *{ box-sizing:border-box; }