*{
    background-color: #fff;
}
.heading {
    text-align: center;
}

.box {
    height: 150px;
    width: 150px;
    border-radius: 20%;
    border: 10px solid black;
    margin: 0.5rem;
    text-align: center;
}

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


.startbtn{
  display:grid;
 justify-content: center;
}

.heading h3 {
    font-size: 1.2rem;
    margin-top: 0.5rem;
    color: #333;
}

.colour1 {
    background-color: blue;
}

.colour2 {
    background-color: yellow;
}

.colour3 {
    background-color: red;
}

.colour4 {
    background-color: green;
}

.flash {
    background-color: white;
}

.userflash {
    background-color: rgb(245, 183, 152);
}

@media screen and (max-width: 991px) {
    .box {
        height: 120px;
        width: 120px;
    }
    h1 {
        font-size: 1.8rem;
    }
    h2 {
        font-size: 1.1rem;
    }
    .btn-container {
        flex-wrap: wrap;
        gap: 0.5rem;
    }
}