* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: #1b1b1e;
  color: #e8e6e1;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  opacity: 1;
  transition: opacity 0.8s ease;
}

#app.exiting {
  opacity: 0;
  pointer-events: none;
}

#topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  font-size: 14px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: #b8b5ae;
  background: #151517;
  border-bottom: 1px solid #2a2a2e;
}

#title {
  font-weight: 600;
  color: #e8e6e1;
}

#page-indicator {
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: #8a877f;
}

#stage {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 12px;
  min-height: 0;
}

#book {
  filter: drop-shadow(0 10px 30px rgba(0, 0, 0, 0.55));
}

#book canvas,
#book img {
  user-select: none;
  -webkit-user-drag: none;
}

.page {
  background: #101012;
  overflow: hidden;
}

.page-surface {
  position: relative;
  width: 100%;
  height: 100%;
}

.page-surface img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.page-number {
  position: absolute;
  left: 50%;
  bottom: 12px;
  transform: translateX(-50%);
  font-size: 13px;
  color: #ffffff;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

.end-surface {
  cursor: pointer;
}

.clickable-photo {
  cursor: pointer;
}

.hotspot {
  position: absolute;
  cursor: zoom-in;
}

.zoom-overlay {
  position: fixed;
  inset: 0;
  z-index: 50;
  background: #000000;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.zoom-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

.zoom-frame {
  background-repeat: no-repeat;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6);
}

/* The end-cover video shows the whole clip (never a cropped sub-region
   like the photo hotspots), so it just fits the viewport directly instead
   of using the box-fit math computed in script.js for .zoom-frame. */
.video-frame {
  width: 100vw;
  height: 100vh;
  object-fit: contain;
}

.end-note {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  padding: 10px 16px;
  text-align: center;
  font-size: 13px;
  line-height: 1.4;
  color: #ffffff;
  background: rgba(10, 10, 12, 0.62);
  pointer-events: none;
}

.nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(20, 20, 22, 0.55);
  color: #e8e6e1;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
  transition: background 0.15s ease, opacity 0.15s ease, transform 0.15s ease;
  z-index: 5;
}

.nav-btn:hover {
  background: rgba(40, 40, 44, 0.8);
}

.nav-btn:active {
  transform: translateY(-50%) scale(0.94);
}

.nav-btn:disabled {
  opacity: 0.25;
  cursor: default;
}

#prev-btn {
  left: 10px;
}

#next-btn {
  right: 10px;
}

#hint {
  flex: 0 0 auto;
  text-align: center;
  font-size: 12px;
  color: #6f6c65;
  padding: 8px 12px 12px;
}

#loading {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  background: #1b1b1e;
  color: #b8b5ae;
  font-size: 14px;
  z-index: 20;
  transition: opacity 0.3s ease;
}

#loading.hidden {
  opacity: 0;
  pointer-events: none;
}

.spinner {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 3px solid rgba(255, 255, 255, 0.15);
  border-top-color: #e8e6e1;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 700px) {
  #topbar {
    font-size: 12px;
    padding: 8px 12px;
  }

  .nav-btn {
    width: 38px;
    height: 38px;
    font-size: 18px;
  }

  #hint {
    font-size: 11px;
  }

  .end-note {
    font-size: 11px;
    padding: 8px 12px;
  }
}

@media (max-width: 480px) {
  #hint {
    display: none;
  }
}