/* Sudoku — cyberpunk theme */
#container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-md);
}

h1 {
  text-align: center;
  color: var(--neon-cyan);
  text-shadow: var(--glow-cyan);
}

#sudoku {
  width: 590px;
  max-width: 100%;
  height: auto;
  list-style: none;
  margin: 0 auto;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 1px;
  background: rgba(0, 240, 255, 0.15);
  border: 2px solid var(--neon-cyan);
  border-radius: 4px;
  box-shadow: var(--glow-cyan);
}

#sudoku li {
  width: 100%;
  aspect-ratio: 1;
  min-height: 50px;
  background: var(--bg-card);
  border: 1px solid rgba(0, 240, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  float: none;
  line-height: 1;
}

#sudoku li:hover {
  background: rgba(0, 240, 255, 0.08);
}

#sudoku li.empty {
  color: var(--neon-cyan);
  text-shadow: var(--glow-cyan);
}

#sudoku li.fixed {
  color: var(--text-muted);
}

#sudoku input {
  width: 100%;
  height: 100%;
  border: none;
  background: transparent;
  text-align: center;
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--neon-cyan);
  padding: 0;
  box-sizing: border-box;
}

#sudoku input:focus {
  outline: 2px solid var(--neon-magenta);
  background: rgba(255, 0, 170, 0.05);
}

p {
  text-align: center;
  margin: var(--space-md) 0;
}

p label {
  margin: 0 var(--space-xs);
  color: var(--text-secondary);
  cursor: pointer;
}

p input[type="radio"] {
  accent-color: var(--neon-cyan);
}

button {
  background: transparent;
  border: 1px solid var(--neon-cyan);
  color: var(--neon-cyan);
  padding: 8px 20px;
  font-size: 1rem;
  font-family: var(--font-body);
  border-radius: var(--radius-sm);
  cursor: pointer;
  margin: var(--space-xs);
  transition: all var(--transition-fast);
}

button:hover {
  background: rgba(0, 240, 255, 0.1);
  box-shadow: var(--glow-cyan);
}

#timer {
  color: var(--neon-yellow);
  font-weight: 600;
  font-size: 1.1rem;
}

@media (max-width: 600px) {
  #sudoku {
    width: 100%;
    max-width: 360px;
  }
  #sudoku li {
    min-height: 36px;
    font-size: 1rem;
  }
}