table {
  border-collapse: collapse;
}
td {
  width: 200px;
  height: 200px;
  text-align: center;
  font-size: 24px;
  border: 1px solid #333;
  cursor: pointer;
}
.empty {
  background: #eee;
  cursor: default;
}
.tab-btn {
  padding: 10px 20px;
  margin-right: 5px;
  border: none;
  background: #eee;
  cursor: pointer;
  font-size: 16px;
  border-radius: 4px 4px 0 0;
}
.tab-btn.active {
  background: #4caf50;
  color: #fff;
}
.tab-content {
  margin-top: 0;
}

#toast {
  visibility: hidden;
  min-width: 200px;
  background: #4caf50;
  color: #fff;
  text-align: center;
  border-radius: 4px;
  padding: 16px;
  position: fixed;
  z-index: 1;
  left: 90%;
  bottom: 30px;
  transform: translateX(-50%);
  font-size: 17px;
}

.container {
  gap: 20px;
  display: flex;
}

.column {
  flex: 1;
}

#puzzle-tab,
#maze-tab,
#extra-ui-maze,
#extra-ui-tictactoe,
#tictactoe-tab,
#extra-ui-sliding {
  padding: 16px;
  border: 1px solid #ccc;
  background-color: #f9f9f9;
}