:root {
  color-scheme: dark;
  --fade-time: 2s;
}

* { box-sizing: border-box; }

html, body {
  width: 100%;
  min-height: 100%;
  margin: 0;
  background: #000;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
}

body { overflow: hidden; }

button { font: inherit; }

.slideshow {
  position: relative;
  width: 100vw;
  height: 100svh;
  min-height: 420px;
  overflow: hidden;
  background: #000;
}

.slides,
.slide {
  position: absolute;
  inset: 0;
}

.slide {
  width: 100%;
  height: 100%;
  object-fit: contain;
  opacity: 0;
  transform: scale(1.008);
  transition: opacity var(--fade-time) ease-in-out, transform 7s ease-out;
  user-select: none;
  -webkit-user-drag: none;
}

.slide.active {
  opacity: 1;
  transform: scale(1);
  z-index: 1;
}

.topbar,
.bottombar {
  position: absolute;
  z-index: 5;
  left: 0;
  width: 100%;
  display: flex;
  align-items: center;
  padding: max(18px, env(safe-area-inset-top)) 24px 18px;
  pointer-events: none;
}

.topbar {
  top: 0;
  justify-content: space-between;
  background: linear-gradient(to bottom, rgba(0,0,0,.72), transparent);
}

.bottombar {
  bottom: 0;
  justify-content: center;
  gap: 18px;
  padding: 40px 24px max(20px, env(safe-area-inset-bottom));
  background: linear-gradient(to top, rgba(0,0,0,.75), transparent);
}

h1 {
  margin: 0;
  font-size: clamp(18px, 2.2vw, 30px);
  font-weight: 500;
  letter-spacing: .12em;
  text-shadow: 0 2px 12px rgba(0,0,0,.65);
}

.sound-button,
.pause-button,
.nav,
.dot {
  pointer-events: auto;
  border: 1px solid rgba(255,255,255,.45);
  color: #fff;
  background: rgba(0,0,0,.35);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  cursor: pointer;
}

.sound-button,
.pause-button {
  border-radius: 999px;
  padding: 9px 14px;
}

.sound-button:hover,
.pause-button:hover,
.nav:hover { background: rgba(255,255,255,.18); }

.sound-icon { margin-right: 5px; }

.nav {
  position: absolute;
  z-index: 5;
  top: 50%;
  width: 48px;
  height: 64px;
  border-radius: 12px;
  transform: translateY(-50%);
  font-size: 42px;
  line-height: 1;
}

.prev { left: 18px; }
.next { right: 18px; }

.counter {
  min-width: 62px;
  font-variant-numeric: tabular-nums;
  text-shadow: 0 1px 8px #000;
}

.dots {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  max-width: min(560px, 55vw);
  pointer-events: auto;
}

.dot {
  width: 9px;
  height: 9px;
  padding: 0;
  border-radius: 50%;
  background: rgba(255,255,255,.35);
}

.dot.active {
  background: #fff;
  transform: scale(1.25);
}

@media (max-width: 700px) {
  .topbar { padding-inline: 14px; }
  .bottombar { gap: 10px; padding-inline: 12px; }
  .nav { width: 40px; height: 54px; font-size: 34px; }
  .prev { left: 8px; }
  .next { right: 8px; }
  .sound-button, .pause-button { padding: 8px 10px; font-size: 13px; }
  .dots { gap: 6px; max-width: 42vw; }
  .dot { width: 7px; height: 7px; }
}

@media (prefers-reduced-motion: reduce) {
  :root { --fade-time: .01s; }
  .slide { transition: opacity .01s linear; transform: none; }
}