/* ============================================================
   FLIPBOOK COMPONENT
   PDF page-flip viewer - PDF.js + StPageFlip
   ============================================================ */

.flipbook {
  width: 100%;
  max-width: 920px;
  margin: 0 auto;
}

/* ---- Stage (holds loader + book) ---- */
.flipbook-stage {
  position: relative;
  width: 100%;
  aspect-ratio: 1.45;
  max-height: 72vh;
  background: var(--bg-alt, #f5f5f5);
  overflow: hidden;
  contain: layout style paint;
}

/* ---- Loader overlay ---- */
.flipbook-loader {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: var(--bg-alt, #f5f5f5);
  transition: opacity 400ms ease;
}

.flipbook-loader.is-hidden {
  opacity: 0;
  pointer-events: none;
}

.flipbook-progress {
  width: clamp(120px, 30%, 200px);
  height: 2px;
  background: var(--border, #e5e7eb);
  overflow: hidden;
}

.flipbook-progress-bar {
  height: 100%;
  width: 0%;
  background: var(--text, #111827);
  transition: width 200ms ease-out;
}

.flipbook-loader-text {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted, #6b7280);
  margin: 0;
}

/* ---- Book container ---- */
.flipbook-book {
  width: 100%;
  height: 100%;
  touch-action: pan-y;
}

/* ---- Pages ---- */
.flipbook-page {
  background: #fff;
  overflow: hidden;
}

.flipbook-page img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  user-select: none;
  pointer-events: none;
  -webkit-user-drag: none;
}

/* ---- Controls ---- */
.flipbook-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  padding: 1rem 0 0;
}

.flipbook-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--border, #e5e7eb);
  border-radius: 50%;
  background: var(--surface, #fff);
  color: var(--muted, #6b7280);
  cursor: pointer;
  transition:
    color 180ms ease-out,
    border-color 180ms ease-out,
    opacity 180ms ease-out;
}

.flipbook-btn:hover {
  color: var(--text, #111827);
  border-color: var(--text, #111827);
}

.flipbook-btn:disabled {
  opacity: 0.25;
  pointer-events: none;
}

.flipbook-btn:focus-visible {
  outline: 2px solid var(--text, #111827);
  outline-offset: 2px;
}

.flipbook-counter {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--muted, #6b7280);
  font-variant-numeric: tabular-nums;
  min-width: 4.5em;
  text-align: center;
}

/* ---- RTL: mirror the book so flips go right-to-left ---- */
.flipbook--rtl .flipbook-book {
  transform: translate3d(0, 0, 0) scaleX(-1);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.flipbook--rtl .flipbook-page img {
  transform: translate3d(0, 0, 0) scaleX(-1);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

/* ---- Error state ---- */
.flipbook-error {
  font-size: 0.85rem;
  color: var(--muted, #6b7280);
  margin: 0;
}

/* ---- Section wrapper (for case-study pages) ---- */
.project-flipbook-section {
  padding: clamp(2rem, 5vw, 3.5rem) 0 clamp(3rem, 7vw, 5rem);
  border-top: 1px solid var(--border, #e5e7eb);
}

.project-flipbook-header {
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}

/* ---- Responsive ---- */
@media (max-width: 640px) {
  .flipbook-stage {
    max-height: 55vh;
  }

  .flipbook-controls {
    gap: 1rem;
  }
}