body {
    background-image: url('s.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    text-align:center;
}
.a1 {
    width: 1000px;
    heigth: 2000px;
    border-radius: 20px;
    border: 2px solid black;
}
.b1 {
    width: 1000px;
    heigth: 2000px;
    border-radius: 20px;
    border: 2px solid black;
}
p {
    color: black;
    font-size: 20px;
}
b {
    color: yellow;
    font-size: 100px;
}
c1 {
    background-image: image; 
}