#kmap-calculator {
  font-family: Arial, sans-serif;
  padding: 20px;
}

#kmap-calculator table {
  border-collapse: collapse;
  margin-top: 15px;
}

#kmap-calculator td, 
#kmap-calculator th {
  width: 50px;
  height: 50px;
  border: 1px solid #444;
  text-align: center;
}

.one { background: #9fdf9f; }
.zero { background: #eee; }
.dc { background: #ffe680; }