body {
  font-family: Arial, sans-serif;
  background-color: #f0f0f0;
  color: #333;
  line-height: 1.6;
  padding: 20px;
  transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
  background-color: #222;
  color: #f0f0f0;
}

.game-container {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.game-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 20px 0;
  padding: 10px;
  background-color: #ddd;
  border-radius: 5px;
}

.difficulty-selector select {
  padding: 5px;
  border-radius: 4px;
  background-color: #fff;
  cursor: pointer;
}

body.dark-mode .difficulty-selector select {
  background-color: #444;
  color: #fff;
}

body.dark-mode .game-controls {
  background-color: #444;
}

.mines-counter,
.timer {
  font-family: monospace;
  font-size: 24px;
  padding: 5px 10px;
  background-color: #000;
  color: red;
  border-radius: 3px;
  min-width: 60px;
}

.reset-btn {
  font-size: 24px;
  width: 80px;
  height: 50px;
  border: none;
  background-color: #ccc;
  border-radius: 50%;
  cursor: pointer;
}

.board-container {
  margin: 20px auto;
}

.board {
  display: flex;
  flex-wrap: wrap;
  width: 336px;
  gap: 2px;
  margin: 0 auto;
  background-color: #999;
}
.board.medium {
  width: 504px; /* 12x12 */
}

.board.hard {
  width: 672px; /* 16x16 */
}

.cell {
  width: 40px;
  height: 40px;
  background-color: #ccc;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  cursor: pointer;
  user-select: none;
  border-radius: 2px;
  flex-shrink: 0;
}

.cell.revealed {
  background-color: #eee;
}

body.dark-mode .cell.revealed {
  background-color: #555;
}

.cell.flagged {
  background-color: #f99;
}

.cell.mine {
  background-color: #f00;
}

.cell[data-value="1"] {
  color: blue;
}
.cell[data-value="2"] {
  color: green;
}
.cell[data-value="3"] {
  color: red;
}
.cell[data-value="4"] {
  color: darkblue;
}
.cell[data-value="5"] {
  color: brown;
}
.cell[data-value="6"] {
  color: teal;
}
.cell[data-value="7"] {
  color: black;
}
.cell[data-value="8"] {
  color: gray;
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  justify-content: center;
  align-items: center;
  z-index: 100;
}

.modal-content {
  background-color: #fff;
  padding: 20px;
  border-radius: 5px;
  max-width: 400px;
  width: 90%;
  text-align: center;
}

body.dark-mode .modal-content {
  background-color: #333;
  color: #fff;
}

.modal h2 {
  margin-top: 0;
}

.modal input {
  display: block;
  width: 80%;
  margin: 10px auto;
  padding: 8px;
}

.modal button {
  margin: 10px 5px;
  padding: 8px 15px;
  cursor: pointer;
}

.main-nav {
  margin-top: 20px;
  display: flex;
  justify-content: center;
  gap: 15px;
}

.main-nav a,
.main-nav button {
  padding: 8px 15px;
  text-decoration: none;
  color: #333;
  background-color: #ddd;
  border: none;
  border-radius: 3px;
  cursor: pointer;
}

body.dark-mode .main-nav a,
body.dark-mode .main-nav button {
  color: #f0f0f0;
  background-color: #444;
}

#ranking-list {
  max-height: 300px;
  overflow-y: auto;
  margin: 15px 0;
}

.ranking-item {
  padding: 8px;
  border-bottom: 1px solid #ddd;
  display: flex;
  justify-content: space-between;
}

body.dark-mode .ranking-item {
  border-bottom-color: #555;
}

.sort-options {
  margin: 10px 0;
}

@media (max-width: 600px) {
  .cell {
    width: 30px;
    height: 30px;
    font-size: 14px;
  }

  .mines-counter,
  .timer {
    font-size: 18px;
    min-width: 50px;
  }

  .reset-btn {
    width: 40px;
    height: 40px;
    font-size: 20px;
  }
}