.button-group {
    display: flex;
    flex-wrap: wrap;
    font-size: 18px; /* 18px = 1em */
    gap: 1em;
}
.button {
    display: inline-block;
    padding: 1em 2.5em;
    background-color: #55337a;
    color: #fff;
    line-height: 1em;
    text-transform: uppercase;
    text-decoration: none;
    border-radius: 1.6em;
    border: 0.1em solid #55337a;
    user-select: none;
}
.button:hover {
    background-color: #fff;
    color: #55337a;
}