body {
    background-image: url(https://opanki.com/fon.gif)
}
h1 {
    text-align: center;
    color: whitesmoke;
}
.btn {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    padding: 10px;
    border-radius: 10px;
    color: black;
    background-color: aquamarine;
    transition: 0.25s ease-in-out;
}
.btn:hover {
    transform: scale(1.1);
    box-shadow: 0 0 50px aquamarine;
    background-color: aqua;
}