:root {
  color-scheme: light;
  font-family: Arial, Helvetica, sans-serif;
  background: #f2f2f2;
  color: #111;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 24px 12px 40px;
}

.page {
  width: 850px;
  max-width: 100%;
  width: min(850px, 100%);
  margin: 0 auto;
}

.return { margin: 0 0 14px; }
.return a { color: #2400c7; }

h1 {
  margin: 0 0 16px;
  font-size: 36px;
  font-size: clamp(24px, 4vw, 36px);
}

.stage {
  position: relative;
  width: 100%;
  height: 0;
  padding-top: 56.25%;
  overflow: hidden;
  background: #111;
}

.slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 180ms linear;
}

.slide.visible { opacity: 1; }

.controls {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 12px;
}

button {
  min-width: 54px;
  min-height: 42px;
  padding: 8px 16px;
  border: 1px solid #555;
  border-radius: 3px;
  background: #fff;
  color: #111;
  font-size: 18px;
  cursor: pointer;
}

#play-stop { min-width: 105px; }
button:hover, button:focus-visible { background: #e3e3e3; }

@media (prefers-reduced-motion: reduce) {
  .slide { transition: none; }
}