:root {
  color-scheme: light dark;
  --bg: #1b1b1f;
  --panel: #232329;
  --text: #f0f0f2;
  --muted: #9a9aa2;
  --accent: #d98e4a;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  display: flex;
  flex-direction: column;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
}

.upload-btn--hidden {
  display: none;
}

.upload-btn {
  background: var(--accent);
  color: #1b1b1f;
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9rem;
}

.upload-btn input {
  display: none;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav button {
  background: transparent;
  border: 1px solid var(--muted);
  color: var(--text);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  font-size: 1.25rem;
  cursor: pointer;
}

.nav button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.nav button:disabled {
  opacity: 0.35;
  cursor: default;
}

#page-indicator {
  min-width: 4.5rem;
  text-align: center;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.zoom {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.zoom button {
  background: transparent;
  border: 1px solid var(--muted);
  color: var(--text);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
}

.zoom button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.zoom button:disabled {
  opacity: 0.35;
  cursor: default;
}

#zoom-indicator {
  min-width: 3.25rem;
  text-align: center;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  font-size: 0.9rem;
}

main#stage {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: 1.5rem;
  overflow: auto;
}

@media (max-width: 600px) {
  main#stage {
    padding: 0.5rem;
  }
}

#book {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s ease;
}

#book > div {
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

#book .page {
  background-size: cover;
  background-position: center;
  background-color: #fff;
}

#status {
  position: absolute;
  color: var(--muted);
  font-size: 0.95rem;
}

#mute-btn {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  border: 1px solid var(--muted);
  background: transparent;
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.7;
  transition: opacity 0.15s ease, border-color 0.15s ease;
}

#mute-btn:hover {
  opacity: 1;
  border-color: var(--accent);
}

#mute-btn::before {
  content: "\1F50A";
  font-size: 1rem;
}

#mute-btn[aria-pressed="true"]::before {
  content: "\1F507";
}

@media (max-width: 480px) {
  .toolbar {
    gap: 0.5rem;
    padding: 0.5rem 0.5rem;
  }

  .nav,
  .zoom {
    gap: 0.35rem;
  }

  .nav button,
  .zoom button,
  #mute-btn {
    width: 1.75rem;
    height: 1.75rem;
    font-size: 0.95rem;
  }

  #page-indicator {
    min-width: 3rem;
    font-size: 0.85rem;
  }

  #zoom-indicator {
    min-width: 2.5rem;
    font-size: 0.75rem;
  }

  #mute-btn::before {
    font-size: 0.85rem;
  }
}