:root {
  color-scheme: dark;
  --bg: #05070b;
  --fg: #f3f6fb;
  --hint-bg: rgba(6, 10, 18, 0.72);
  --status-bg: rgba(130, 22, 22, 0.92);
  --shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
  --transition-duration: 650ms;
  font-family: "Segoe UI", "Noto Sans TC", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(circle at top, #182235 0%, var(--bg) 56%);
}

body {
  min-height: 100vh;
}

.app {
  min-height: 100vh;
}

.stage {
  position: relative;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background: transparent;
  cursor: default;
}

.stage.is-waiting {
  cursor: pointer;
}

.media {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  opacity: 0;
  transition: opacity var(--transition-duration) ease;
  will-change: opacity;
}

.media-active {
  opacity: 1;
}

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

.hint,
.status {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  color: var(--fg);
  z-index: 2;
}

.hint {
  bottom: 32px;
  padding: 12px 20px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  background: var(--hint-bg);
  box-shadow: var(--shadow);
  letter-spacing: 0.08em;
  animation: hintPulse 1.8s ease-in-out infinite;
}

.status {
  top: 24px;
  max-width: min(80vw, 720px);
  padding: 14px 18px;
  border-radius: 14px;
  background: var(--status-bg);
  box-shadow: var(--shadow);
}

.hint-hidden,
.status-hidden {
  display: none;
}

@keyframes hintPulse {
  0%,
  100% {
    transform: translateX(-50%) translateY(0);
    opacity: 0.92;
  }

  50% {
    transform: translateX(-50%) translateY(-3px);
    opacity: 1;
  }
}