body {
  background-color: #121a2f;
  color: #fff;
  font-family: Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  height: 100vh;
  margin: 0;
}

h1 {
  font-size: 2em;
  margin-bottom: 20px;
}

.sudoku-container {
  text-align: center;
}

#sudoku-board {
  display: flex;
  flex-direction: column;
  margin: 0 auto 20px;
}

.sudoku-row {
  display: flex;
}

.cell {
  width: 40px;
  height: 40px;
  text-align: center;
  font-size: 20px;
  border: 1px solid #444;
  background-color: #2b2f3a;
  color: white;
  outline: none;
}

.prefilled {
  background-color: #3c475c;
}

button {
  padding: 10px 20px;
  background-color: #28a7e9;
  border: none;
  border-radius: 5px;
  color: white;
  font-size: 1em;
  cursor: pointer;
}

#message {
  margin-top: 15px;
  font-size: 1.1em;
}

/* Match navigation button style from BarnCrush */
.nav-button + .nav-button {
  margin-left: 10px;
}

.nav-button {
  background-color: #3b82f6;
  color: #fff;
  border: none;
  border-radius: 4px;

  font-size: 1rem;
  display: inline-block;
  padding: 6px 12px;
  text-decoration: none;
  cursor: pointer;
}

.nav-button:hover {
  background-color: #2563eb;
}