* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: #0a1420;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: #eaf6ff;
}

.hidden {
  display: none !important;
}

#back-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 30;
  background: rgba(6, 14, 22, 0.65);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
  font-size: 0.85rem;
  color: #eaf6ff;
  text-decoration: none;
}

#back-link:hover {
  background: rgba(6, 14, 22, 0.85);
}

button {
  padding: 0.6rem 1.25rem;
  border: none;
  border-radius: 8px;
  background: linear-gradient(135deg, #34e89e, #3b9dff);
  color: #04121c;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
}

button.small-btn {
  padding: 0.4rem 0.9rem;
  font-size: 0.85rem;
}

#top-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 1rem;
  padding-left: 9rem;
  background: rgba(6, 14, 22, 0.75);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

#status-label {
  flex: 1;
  font-size: 0.85rem;
  color: #a7bdd1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#board-wrap {
  position: fixed;
  inset: 0;
  padding-top: 3.2rem;
  padding-bottom: 4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

#board {
  background: #ffffff;
  touch-action: none;
  max-width: 100%;
  max-height: 100%;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

#toolbar {
  position: fixed;
  bottom: 1rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(6, 14, 22, 0.85);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 999px;
  padding: 0.5rem 1rem;
}

#color-swatches {
  display: flex;
  gap: 0.3rem;
}

.color-swatch {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.3);
  cursor: pointer;
  padding: 0;
}

.color-swatch.active {
  border-color: #fff;
}

#toast {
  position: fixed;
  bottom: 5rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(6, 14, 22, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  z-index: 30;
}

@media (max-width: 480px) {
  #top-bar {
    padding-left: 1rem;
    padding-top: 3rem;
    flex-wrap: wrap;
  }
  #board-wrap {
    padding-top: 5.5rem;
  }
}