body {
    text-align: center;
    background-color: yellow;
}

.btn {
    height: 150px;
    width: 150px;
    border-radius: 20%;
    border: 10px solid black;
    margin: 2.5rem;
}

.btn-container {
    display: flex;
    justify-content: center;
}

.yellow  {
    background-color: #f99b45;
}

.red{
    background-color: #d95980;
}

.purple {
    background-color: #819ff9;
}

.green {
    background-color: #63aac0;
}

.flash {
    background-color: #fff;
}

.userflash{
    background-color: green;
}

.hidden {
    display: none;
}


@media(max-width: 1200px){
    .btn{
        height: 150px;
        width:150px;
        margin: 1.5rem;
    }
}

@media(max-width: 768px){
    .btn{
        height: 100px;
        width:100px;
        margin: 1rem;
        border-radius: 20%;
        border: 7px solid black;
    }
}

@media(max-width: 480px){
    .btn{
        height: 75px;
        width:75px;
        margin: 0.5rem;
        border-radius: 20%;
        border: 5px solid black;
    }

    h1, h2 {
        font-size: 1.5rem;
    }
}


#start-btn{
    padding: 10px 15px;
    font-size: 20px;
    font-weight: bold;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin: 20px auto;
    display: block;
}

#start-btn:hover {
    background-color: 45a049;
}

#congrats-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.congrats-content {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 5px 15px  rgba(0, 0, 0, 0.3);
}

#close-btn {
    padding: 10px 15px;
    font-size: 16px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}


#close-btn:hover {
   background-color: 45a049;
}