body {
    text-align: center;
    background-color: #7F8CAA;
    font-family: 'Arial', sans-serif;
}

#level-title {
    color: white;
    font-size: 2rem;
    margin: 40px;
}

.container {
    display: grid;
    grid-template-columns: repeat(2, 150px);
    grid-template-rows: repeat(2, 150px);
    gap: 20px;
    justify-content: center;
}

.btn {
    border: 10px solid black;
    border-radius: 20%;
    cursor: pointer;
    transition: all 0.2s;
}

.green {
    background-color: #00A74A;
}

.red {
    background-color: #9F0F17;
}

.yellow {
    background-color: #CCA707;
}

.blue {
    background-color: #094A8F;
}

.pressed {
    box-shadow: 0 0 20px white;
    opacity: 0.5;
}

#start-btn {
    margin-top: 30px;
    padding: 15px 30px;
    font-size: 1.2rem;
    border: none;
    border-radius: 10px;
    background-color: #4CAF50;
    color: white;
    cursor: pointer;
}