/* Introduction overlay */
#introOverlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(17, 17, 17, 0.95);
  color: #eee;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  flex-direction: column;
  text-align: center;
  padding: 20px;
  box-sizing: border-box;
}

#introContent h1 {
  font-size: 2em;
}

#introContent h2 {
  font-size: 1.5em;
}

#introContent p {
  font-size: 1.0em;
}

#introContent h1,
#introContent h2,
#introContent p {
  margin: 0.5em;
}

#introContent {
  max-width: 420px;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.buttonGrid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.buttonGrid3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
}

.btn {
  background: linear-gradient(135deg, #4caf50, #81c784);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  border-radius: 10px;
  
  padding: 6px 0;

  color: rgba(17, 17, 17, 0.95);
  font-size: 15px;
  font-weight: 1000;
}

#introFooter {
  font-size: 12px;
  color: #aaa;
  text-align: center;
  margin-top: 16px;
  opacity: 0.8;
}

.hidden {
  display: none !important;
}

/* Tutorial */
#tutorialOverlay {
  position: fixed;
  inset: 0;
  background: rgba(17, 17, 17, 0.95);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
}

#tutorialContent {
  max-width: 600px;
  padding: 2rem;
  background: #111;
  border-radius: 12px;
  text-align: center;
}

#tutorialNav {
  display: flex;
  justify-content: space-between;
  margin-top: 2rem;
  gap: 1rem;
}

#tutorialFooter {
  margin-top: 1.5rem;
  font-size: 0.9rem;
  opacity: 0.7;
}

#tutorialNav button {
  flex: 1;
}

#tutorialFooter button {
  width: 100%;
  margin-top: 1rem;
}

#tutorialImageWrapper {
  margin: 1.5rem 0;
}

#tutorialImage {
  max-width: 60%;
  border-radius: 10px;
}