/* ── Slide container ── */
#slideContainer {
  position: relative;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
}

.slide {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity .4s ease;
}
.slide.active {
  opacity: 1;
  pointer-events: auto;
}

.slide-content {
  width: min(calc(100vw - 100px), 1100px);
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  scrollbar-width: none;
}
.slide-content::-webkit-scrollbar { display: none }

/* ── Navigation arrows ── */
.nav-arrow {
  position: fixed;
  top: 0;
  bottom: 0;
  width: 60px;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: .25;
  transition: opacity .25s;
  -webkit-user-select: none;
  user-select: none;
}
.nav-arrow:hover { opacity: .7 }
.nav-arrow svg {
  width: 28px;
  height: 28px;
  stroke: var(--muted);
  stroke-width: 2;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 0 8px rgba(0,0,0,.5));
}
.nav-prev { left: 0 }
.nav-next { right: 0 }

/* ── Page indicator ── */
.page-indicator {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}
.page-indicator .current { color: var(--accent); font-weight: 700 }

/* ── Progress bar ── */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-dim));
  z-index: 60;
  transition: width .35s ease;
  box-shadow: 0 0 8px var(--accent-glow);
}

/* ── Slide-specific layouts ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}
.three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.four-col {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

@media (max-width: 900px) {
  .slide-content { width: calc(100vw - 48px) }
  .two-col { grid-template-columns: 1fr; gap: 20px }
  .three-col { grid-template-columns: 1fr; gap: 14px }
  .four-col { grid-template-columns: 1fr; gap: 14px }
  .nav-arrow { width: 40px }
}