body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f0f0;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    padding: 20px;
    max-width: 800px;
    width: 100%;
}

h1 {
    text-align: center;
    color: #333;
    margin-top: 0;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.controls {
    display: flex;
    gap: 10px;
}

button {
    background-color: #4CAF50;
    border: none;
    color: white;
    padding: 10px 15px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    cursor: pointer;
    border-radius: 5px;
    transition: all 0.3s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

button:hover {
    background-color: #45a049;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#resetBtn {
    background-color: #f44336;
}

#resetBtn:hover {
    background-color: #d32f2f;
}

#solveBtn {
    background-color: #2196F3;
}

#solveBtn:hover {
    background-color: #0b7dda;
}

.difficulty {
    display: flex;
    align-items: center;
    gap: 10px;
}

select {
    padding: 8px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

.game-container {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}

#gameCanvas {
    border: 2px solid #333;
    background-color: #fff;
    cursor: pointer;
}

#gameCanvas:hover {
    border-color: #4CAF50;
}

.instructions {
    background-color: #e9f7ef;
    border-left: 5px solid #4CAF50;
    padding: 15px;
    border-radius: 5px;
}

.instructions h2 {
    margin-top: 0;
    color: #333;
}

.instructions ul {
    padding-left: 20px;
}

.instructions li {
    margin-bottom: 8px;
}

.message {
    padding: 10px;
    margin: 10px 0;
    border-radius: 5px;
    text-align: center;
    font-weight: bold;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease;
}

.message.show {
    opacity: 1;
    transform: translateY(0);
}

.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.input-number {
    position: absolute;
    background: transparent;
    border: 2px solid #4CAF50;
    border-radius: 5px;
    font-size: 24px;
    font-weight: bold;
    text-align: center;
    outline: none;
    z-index: 10;
}