body {
  margin: 0;
  background-color: #0d1117;
  color: #f0f6fc;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
.navbar {
  background-color: #161b22;
  padding: 1rem;
}
.btn-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 10px;
  padding: 1rem;
}
.btn-sound {
  background-color: #21262d;
  color: #f0f6fc;
  border: none;
  border-radius: 12px;
  padding: 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  transition: all 0.3s ease;
  cursor: pointer;
}
.btn-sound:hover {
  background-color: #30363d;
  transform: scale(1.05);
}