body {
    margin: 0;
    overflow: hidden;
    font-family: Arial, sans-serif;
    background-color: #121212;
    color: #ffffff;
}

canvas {
    display: block;
}

#score {
    position: absolute;
    top: 10px;
    left: 10px;
    font-size: 24px;
    z-index: 1;
}

#game-over, #start-screen {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 48px;
    background-color: rgba(0, 0, 0, 0.7);
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    z-index: 2;
}

#game-over {
    display: none;
}

.btn {
    font-size: 24px;
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #0077ff;
    color: white;
    border: none;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #005bb5;
}