/* ============================================================================
   Folding Brochure Viewer
   Fysieke klikroute: voorkant -> binnenzijde -> spread -> 3 panelen -> achterkant.
   ========================================================================= */

:root {
  --bg-0: #eef1ee;
  --bg-1: #dfe4df;
  --ink: #181916;
  --ink-soft: #626a62;
  --ink-faint: rgba(24, 25, 22, 0.42);

  --paper: #fbfaf6;
  --paper-back: #f1efe8;
  --chrome-bg: rgba(255, 255, 255, 0.74);
  --chrome-border: rgba(24, 25, 22, 0.1);
  --chrome-ink: #22251f;

  --ease-soft: cubic-bezier(0.22, 0.61, 0.36, 1);
  --ease-fold: cubic-bezier(0.38, 0.02, 0.16, 1);
  --dur-fold: 900ms;

  --aspect: 0.707;
  --panel-w: 320px;
  --panel-h: 453px;
  --view-panels: 1;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  height: 100vh;
  overflow: hidden;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 14px;
  color: var(--ink);
  background: var(--bg-0);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

button,
img {
  user-select: none;
  -webkit-user-drag: none;
}

button {
  font: inherit;
}

.stage {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  overflow: hidden;
  perspective: 2300px;
  perspective-origin: 50% 44%;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.34), transparent 42%),
    radial-gradient(ellipse 120% 78% at 50% 42%, var(--bg-0), var(--bg-1));
}

.stage-surface {
  position: absolute;
  left: 50%;
  bottom: 9vh;
  width: min(76vw, 980px);
  height: 15vh;
  transform: translateX(-50%);
  background: radial-gradient(
    ellipse at center,
    rgba(0, 0, 0, 0.16) 0%,
    rgba(0, 0, 0, 0.07) 34%,
    rgba(0, 0, 0, 0) 70%
  );
  filter: blur(16px);
  opacity: 0.58;
  pointer-events: none;
  transition:
    width var(--dur-fold) var(--ease-soft),
    opacity var(--dur-fold) var(--ease-soft);
}

.folding-brochure {
  position: relative;
  width: calc(var(--panel-w) * var(--view-panels));
  height: var(--panel-h);
  z-index: 2;
  transform-style: preserve-3d;
  transition:
    width 520ms var(--ease-soft),
    height 520ms var(--ease-soft),
    transform 520ms var(--ease-soft);
}

.folding-brochure[data-state="front"],
.folding-brochure[data-state="back"] {
  cursor: pointer;
}

.folding-brochure[data-state="front"]:hover,
.folding-brochure[data-state="back"]:hover {
  transform: translateY(-4px) rotateX(0.8deg);
}

.brochure-shadow {
  position: absolute;
  left: 5%;
  right: 5%;
  bottom: -6.5%;
  height: 6.5%;
  background: radial-gradient(
    ellipse at center,
    rgba(0, 0, 0, 0.28) 0%,
    rgba(0, 0, 0, 0.09) 42%,
    rgba(0, 0, 0, 0) 74%
  );
  filter: blur(14px);
  opacity: 0.52;
  pointer-events: none;
  transition:
    left var(--dur-fold) var(--ease-soft),
    right var(--dur-fold) var(--ease-soft),
    opacity var(--dur-fold) var(--ease-soft);
}

.folding-brochure[data-state="front"] .brochure-shadow,
.folding-brochure[data-state="back"] .brochure-shadow {
  left: 10%;
  right: 10%;
  opacity: 0.44;
}

.fold-root {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
}

.brochure-layout {
  position: absolute;
  left: 50%;
  top: 50%;
  width: var(--panel-w);
  height: var(--panel-h);
  transform: translate3d(-50%, -50%, 0) rotateX(0.7deg);
  transform-style: preserve-3d;
  transition: transform var(--dur-fold) var(--ease-soft);
}

.folding-brochure[data-state="cover-back"] .brochure-layout {
  transform: translate3d(50%, -50%, 0) rotateX(0.9deg);
}

.folding-brochure[data-state="back"] .brochure-layout {
  transform: translate3d(-50%, -50%, 0) rotateX(0.7deg) rotateY(180deg);
}

.folding-brochure[data-state="spread-open"] .brochure-layout {
  transform: translate3d(0, -50%, 0) rotateX(0.9deg);
}

.folding-brochure[data-state="right-closed"] .brochure-layout {
  transform: translate3d(-50%, -50%, 0) rotateX(0.9deg);
}

.folding-brochure[data-state="triple-open"] .brochure-layout {
  transform: translate3d(-50%, -50%, 0) rotateX(0.9deg);
}

.brochure-panel {
  position: absolute;
  top: 0;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
}

.physical-flap {
  will-change: transform;
  transition: transform var(--dur-fold) var(--ease-fold);
}

.cover-flap {
  left: 0;
  z-index: 35;
  transform-origin: left center;
  transform: rotateY(0deg) translateZ(1px);
}

.folding-brochure[data-state="cover-back"] .cover-flap,
.folding-brochure[data-state="spread-open"] .cover-flap,
.folding-brochure[data-state="triple-open"] .cover-flap,
.folding-brochure[data-state="right-closed"] .cover-flap {
  transform: rotateY(-180deg) translateZ(0);
}

.folding-brochure[data-state="right-closed"] .cover-flap,
.folding-brochure[data-state="back"] .cover-flap,
.folding-brochure[data-motion="closing-back"] .cover-flap,
.folding-brochure[data-motion="opening-back"] .cover-flap {
  visibility: hidden;
}

.right-stack {
  left: 0;
  z-index: 30;
  visibility: hidden;
  transform-origin: left center;
  transform: rotateY(178deg) translateZ(-1px);
  transition: transform var(--dur-fold) var(--ease-fold);
  will-change: transform;
}

.folding-brochure[data-state="spread-open"] .right-stack,
.folding-brochure[data-state="triple-open"] .right-stack,
.folding-brochure[data-state="right-closed"] .right-stack,
.folding-brochure[data-state="back"] .right-stack,
.folding-brochure[data-motion="opening-right"] .right-stack,
.folding-brochure[data-motion="closing-right"] .right-stack,
.folding-brochure[data-motion="opening-extra"] .right-stack,
.folding-brochure[data-motion="closing-extra"] .right-stack,
.folding-brochure[data-motion="opening-extra-forward"] .right-stack,
.folding-brochure[data-motion="closing-extra-backward"] .right-stack,
.folding-brochure[data-motion="closing-back"] .right-stack,
.folding-brochure[data-motion="opening-back"] .right-stack {
  visibility: visible;
}

.folding-brochure[data-state="spread-open"] .right-stack,
.folding-brochure[data-state="triple-open"] .right-stack,
.folding-brochure[data-state="right-closed"] .right-stack {
  transform: rotateY(0deg) translateZ(0);
}

.folding-brochure[data-state="back"] .right-stack {
  z-index: 32;
  transform: rotateY(0deg) translateZ(0);
}

.folding-brochure[data-state="back"][data-motion="closing-back"] .brochure-layout {
  transform: translate3d(-50%, -50%, 0) rotateX(0.9deg) rotateY(180deg);
}

.folding-brochure[data-state="back"][data-motion="opening-back"] .brochure-layout {
  transform: translate3d(-50%, -50%, 0) rotateX(0.9deg) rotateY(180deg);
}

.right-flap {
  left: 0;
  z-index: 20;
  transform-origin: center center;
  transform: none;
  transition: none;
}

.solo-panel {
  left: 0;
  opacity: 0;
  pointer-events: none;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  transition: opacity var(--dur-fold) var(--ease-fold);
  z-index: 70;
}

.final-panel {
  z-index: 80;
  transform: rotateY(0deg) translateZ(2px);
}

.back-panel {
  transform: rotateY(180deg) translateZ(2px);
}

.folding-brochure[data-state="right-closed"] .final-panel,
.folding-brochure[data-state="back"] .final-panel {
  opacity: 1;
}

.folding-brochure[data-state="right-closed"] .back-panel,
.folding-brochure[data-state="back"] .back-panel,
.folding-brochure[data-motion="closing-back"] .back-panel,
.folding-brochure[data-motion="opening-back"] .back-panel {
  opacity: 1;
}


.extra-flap {
  left: 100%;
  z-index: 46;
  visibility: hidden;
  transform-origin: left center;
  transform: rotateY(178deg) translateZ(-1px);
  transition: transform var(--dur-fold) var(--ease-fold),
    opacity var(--dur-fold) var(--ease-fold);
}

.folding-brochure[data-state="triple-open"] .extra-flap,
.folding-brochure[data-state="right-closed"] .extra-flap,
.folding-brochure[data-motion="opening-extra"] .extra-flap,
.folding-brochure[data-motion="closing-extra"] .extra-flap,
.folding-brochure[data-motion="opening-extra-forward"] .extra-flap,
.folding-brochure[data-motion="closing-extra-backward"] .extra-flap {
  visibility: visible;
}

.folding-brochure[data-state="triple-open"] .extra-flap {
  transform: rotateY(0deg) translateZ(1px);
}

.folding-brochure[data-state="right-closed"] .extra-flap,
.folding-brochure[data-motion="closing-back"] .extra-flap,
.folding-brochure[data-motion="opening-back"] .extra-flap {
  transform: rotateY(178deg) translateZ(1px);
}

.folding-brochure[data-state="back"] .extra-flap {
  transform: rotateY(178deg) translateZ(1px);
  opacity: 0;
}


.panel-face {
  position: absolute;
  inset: 0;
  overflow: hidden;
  border: 1px solid rgba(24, 25, 22, 0.08);
  border-radius: 6px;
  background: var(--paper);
  box-shadow:
    0 1px 1px rgba(0, 0, 0, 0.04),
    0 9px 24px rgba(0, 0, 0, 0.07),
    0 24px 54px rgba(0, 0, 0, 0.08);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.panel-face--back {
  transform: rotateY(180deg);
  background:
    radial-gradient(
      ellipse 80% 60% at 50% 38%,
      rgba(255, 255, 255, 0.52),
      rgba(255, 255, 255, 0) 70%
    ),
    linear-gradient(90deg, rgba(0, 0, 0, 0.06), transparent 18%),
    linear-gradient(135deg, var(--paper-back), #f8f6ef);
}

.panel-face img {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.panel-print {
  z-index: 1;
}

.panel-face::before,
.panel-face::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.panel-face::before {
  z-index: 3;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.13), transparent 9%),
    linear-gradient(270deg, rgba(255, 255, 255, 0.4), transparent 10%);
  opacity: 0.36;
}

.panel-face::after {
  z-index: 4;
  border-radius: inherit;
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.18),
    inset 10px 0 20px rgba(0, 0, 0, 0.045),
    inset -8px 0 18px rgba(255, 255, 255, 0.16);
}

.cover-flap .panel-face--front,
.folding-brochure[data-state="back"] .extra-flap .panel-face--back {
  box-shadow:
    0 2px 4px rgba(0, 0, 0, 0.06),
    0 16px 38px rgba(0, 0, 0, 0.1),
    0 46px 90px rgba(0, 0, 0, 0.11);
}

.physical-flap::before,
.right-stack::before {
  content: "";
  position: absolute;
  left: -1px;
  top: -1.5%;
  bottom: -1.5%;
  width: 22px;
  transform: translateZ(2px);
  background: linear-gradient(
    90deg,
    rgba(0, 0, 0, 0.2),
    rgba(0, 0, 0, 0.08) 34%,
    rgba(255, 255, 255, 0.18) 66%,
    rgba(255, 255, 255, 0)
  );
  opacity: 0;
  pointer-events: none;
  transition: opacity 320ms var(--ease-soft);
}

.folding-brochure:not([data-state="front"]) .cover-flap::before,
.folding-brochure[data-state="spread-open"] .right-stack::before,
.folding-brochure[data-state="triple-open"] .right-stack::before,
.folding-brochure[data-state="right-closed"] .right-stack::before,
.folding-brochure[data-state="back"] .right-stack::before,
.folding-brochure[data-state="triple-open"] .extra-flap::before,
.folding-brochure[data-state="right-closed"] .extra-flap::before,
.folding-brochure[data-motion="opening-extra"] .extra-flap::before,
.folding-brochure[data-motion="closing-extra"] .extra-flap::before,
.folding-brochure[data-motion="opening-right"] .right-stack::before,
.folding-brochure[data-motion="closing-right"] .right-stack::before,
.folding-brochure[data-motion="closing-back"] .right-stack::before,
.folding-brochure[data-motion="opening-back"] .right-stack::before {
  opacity: 0.58;
}

.fold-edge {
  position: absolute;
  top: -18%;
  bottom: -18%;
  width: 50vw;
  padding: 0;
  border: 0;
  background: transparent;
  opacity: 0;
  cursor: pointer;
  z-index: 80;
}

.fold-edge:disabled {
  pointer-events: none;
}

.fold-edge--prev {
  right: 50%;
}

.fold-edge--next {
  left: 50%;
}

.chrome {
  position: fixed;
  left: 50%;
  bottom: calc(env(safe-area-inset-bottom, 0px) + 22px);
  transform: translate(-50%, 10px);
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 6px;
  border: 1px solid var(--chrome-border);
  border-radius: 999px;
  background: var(--chrome-bg);
  color: var(--chrome-ink);
  box-shadow:
    0 1px 1px rgba(0, 0, 0, 0.04),
    0 12px 32px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 420ms var(--ease-soft),
    transform 420ms var(--ease-soft);
  z-index: 20;
}

body:has(.folding-brochure:not([data-state="front"])) .chrome {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, 0);
}

.chrome-btn {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: inherit;
  cursor: pointer;
  transition:
    background 180ms var(--ease-soft),
    color 180ms var(--ease-soft),
    transform 180ms var(--ease-soft);
}

.chrome-btn:hover {
  background: rgba(24, 25, 22, 0.06);
}

.chrome-btn:active {
  transform: scale(0.96);
}

.chrome-btn:disabled {
  color: var(--ink-faint);
  cursor: default;
}

.chrome-btn:disabled:hover {
  background: transparent;
}

.chrome-btn svg {
  width: 18px;
  height: 18px;
}

.chrome-counter {
  min-width: 56px;
  padding: 0 8px;
  color: var(--ink-soft);
  font-size: 11px;
  letter-spacing: 0.08em;
  line-height: 1;
  text-align: center;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.chrome-divider {
  width: 1px;
  height: 18px;
  margin: 0 4px;
  background: var(--chrome-border);
}

@media (max-width: 720px) {
  .stage {
    perspective: 1650px;
    perspective-origin: 50% 42%;
    align-items: center;
    justify-items: start;
    overflow-x: auto;
    overflow-y: hidden;
    padding-inline: max(18px, calc((100vw - var(--panel-w)) / 2));
    touch-action: pan-x;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .stage::-webkit-scrollbar {
    display: none;
  }

  .fold-edge {
    display: none;
  }

  .stage-surface {
    bottom: 13vh;
    width: 94vw;
    opacity: 0.46;
  }

  .panel-face {
    border-radius: 5px;
  }

  .physical-flap::before,
  .right-stack::before {
    width: 18px;
  }

  .chrome {
    bottom: calc(env(safe-area-inset-bottom, 0px) + 14px);
    padding: 5px;
  }

  .chrome-btn {
    width: 34px;
    height: 34px;
  }

  .chrome-counter {
    min-width: 50px;
    font-size: 10px;
    padding: 0 4px;
  }

  .chrome-divider {
    margin: 0 2px;
  }
}

@media (max-width: 380px) {
  .chrome-counter {
    min-width: 46px;
  }

  .chrome-btn {
    width: 32px;
    height: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --dur-fold: 240ms;
  }

  .folding-brochure,
  .brochure-layout,
  .physical-flap,
  .chrome,
  .brochure-shadow,
  .stage-surface {
    transition-duration: 120ms !important;
  }

  .folding-brochure[data-state="front"]:hover {
    transform: none;
  }
}

.stage:fullscreen,
.stage:-webkit-full-screen {
  --bg-0: #181a18;
  --bg-1: #10120f;
  --chrome-bg: rgba(22, 24, 21, 0.74);
  --chrome-border: rgba(255, 255, 255, 0.1);
  --chrome-ink: #f3f1eb;
  --ink-soft: rgba(243, 241, 235, 0.68);
  --ink-faint: rgba(243, 241, 235, 0.38);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.04), transparent 42%),
    radial-gradient(ellipse 120% 78% at 50% 42%, #1a1c19, #0d0e0c);
}