body, html {
    margin: 0;
    padding: 0;
    overflow: hidden;
    height: 100%;
    background: #000;
}

canvas {
    display: block;
}

#game-container {
    width: 100%;
    height: 100%;
    display: block;
}

#game-over {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-family: Arial, sans-serif;
}

#game-over h1 {
    font-size: 3em;
    margin-bottom: 20px;
}

#restart-button {
    padding: 10px 20px;
    font-size: 1.2em;
    background-color: #ff5555;
    border: none;
    color: #fff;
    cursor: pointer;
    border-radius: 5px;
}

#restart-button:hover {
    background-color: #ff0000;
}

@media (max-width: 600px) {
    #game-over {
        width: 80%;
        padding: 15px;
    }

    #restart-button {
        width: 100%;
        font-size: 14px;
    }
}