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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #282c34;
    font-family: 'Arial', sans-serif;
    color: white;
}

.container {
    text-align: center;
    background-color: #3c4047;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

h1 {
    margin-bottom: 20px;
    font-size: 28px;
}

.mode-selection {
    margin-bottom: 20px;
}

button {
    padding: 10px 20px;
    margin: 10px;
    cursor: pointer;
    background-color: #61dafb;
    border: none;
    border-radius: 5px;
    color: #282c34;
    font-weight: bold;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #21a1f1;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-template-rows: repeat(3, 100px);
    gap: 10px;
    justify-content: center;
    margin-top: 20px;
}

.cell {
    width: 100px;
    height: 100px;
    background-color: #444b55;
    border-radius: 10px;
    font-size: 36px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.cell:hover {
    background-color: #555d6a;
}

.game-info {
    margin-top: 20px;
}

#restart {
    margin-top: 20px;
    display: none;
    background-color: #61dafb;
    border-radius: 5px;
    color: #282c34;
    font-weight: bold;
}

#restart:hover {
    background-color: #21a1f1;
}