* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    max-width: 800px;
    width: 100%;
    padding: 20px;
}

.home-container, .new-game-container, .game-container {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    margin-bottom: 20px;
    color: #333;
}

.button-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: center;
}

.btn {
    padding: 10px 20px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    background-color: #45a049;
}

.join-game {
    display: flex;
    gap: 10px;
}

.join-game input {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    width: 200px;
}

.number-pad {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
    margin-bottom: 20px;
    max-width: 450px;
    margin-left: auto;
    margin-right: auto;
}

.number-btn {
    padding: 10px;
    font-size: 20px;
    background-color: #f0f0f0;
    border: 2px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
    position: relative;
}

.number-btn .remaining-count {
    font-size: 12px;
    color: #666;
    position: absolute;
    bottom: 2px;
    right: 2px;
}

.number-btn:hover {
    background-color: #e0e0e0;
}

.number-btn.active {
    background-color: #4CAF50;
    color: white;
    border-color: #45a049;
}

.number-btn.active .remaining-count {
    color: rgba(255, 255, 255, 0.8);
}

.clear-btn {
    grid-column: span 2;
    background-color: #f44336;
    color: white;
    border-color: #d32f2f;
}

.clear-btn:hover {
    background-color: #d32f2f;
}

.clear-btn.active {
    background-color: #d32f2f;
    border-color: #b71c1c;
}

.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 1px;
    background-color: #333;
    border: 2px solid #333;
    margin: 20px auto;
    max-width: 450px;
}

.row {
    display: contents;
}

.cell {
    background-color: white;
    aspect-ratio: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.2s;
}

.cell:hover {
    background-color: #f0f0f0;
}

.cell-value {
    font-size: 24px;
    font-weight: bold;
    color: #333;
}

.cell.starting-cell {
    background-color: #f0f0f0;
    cursor: not-allowed;
}

.cell.starting-cell .cell-value {
    color: #000;
}

.cell.edited-cell {
    background-color: #e6ffe6;
}

.cell.other-user-cell {
    background-color: #e6f3ff;
}

.cell.other-user-cell .cell-value {
    color: #0066cc;
}

.cell.invalid {
    background-color: #ffebee;
}

.cell.invalid .cell-value {
    color: #c62828;
}

/* Add borders for 3x3 boxes */
.cell:nth-child(3n) {
    border-right: 2px solid #333;
}

.row:nth-child(3n) .cell {
    border-bottom: 2px solid #333;
}

.player-info {
    text-align: center;
    margin-bottom: 20px;
    padding: 10px;
    background-color: #f8f8f8;
    border-radius: 4px;
}

.username {
    font-size: 16px;
    color: #666;
}

.username span {
    font-weight: bold;
    color: #333;
}