html, body {
    height: 100%;
    width: 100%;
}

* {
    margin: 0;
    padding: 0;
}

body {
    background-color: #000000;
}

p {
    margin-bottom: 0;
}

.main {
    display: grid;
    height: 100%;
}

.footer {
    width: 100%;
    white-space: nowrap;
}

.pic {
    max-height: calc(100% - 3em);
    max-width: 100%;
    position: fixed;
    left: 50%;
    transform: translate(-50%, 0);
}

.pic-vertical {
    max-height: calc(100% - 6em);
}

.btn {
    height: 3em;
}

.btn-group {
    margin-top: -3em;
}

.btn-group-vertical {
    margin-top: -6em;
}