body {
  font-family: Arial, sans-serif;
  background-color: #f2f2f2;
  margin: 0;
  padding: 20px;
}
.container {
  max-width: 600px;
  margin: auto;
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
h1 {
  text-align: center;
}
.form-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 15px;
}
.form-group label {
  grid-column: span 1;
}
.form-group input {
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
}
#solveBtn {
  display: block;
  width: 100%;
  padding: 10px;
  background: #007bff;
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 16px;
  cursor: pointer;
}
#solveBtn:hover {
  background: #0056b3;
}

#fill-btn {
  display: block;
  width: 50%;
  padding: 10px;
  background: #007bff;
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 16px;
  cursor: pointer;
  margin-top: 20px;
}
#fill-btn:disabled {
  background-color:#ccc;
}
#fill-btn:disabled:hover {
  pointer-events: none;
  background: #ccc!important;  /* or the disabled background color */  
}

#fill-btn:hover {
  background: #0056b3;
}


#output {
  margin-top: 20px;
  white-space: pre-wrap;
  font-family: monospace;
}