* {
    max-width: 80ch;
    font-family: Libertinus Serif, serif;
}
.warn {
    background-color: lavenderblush;
    border: solid 5px lightcoral;
}
.warn-light {
    background-color: ivory;
    border: solid 5px khaki;
}
.info {
    background-color: azure;
    border: solid 5px lightblue;
}
.warn, .warn-light, .info, footer { padding: 2%; }
footer {
    margin-top: 5%;
    background-color: whitesmoke;
    border: solid 5px slategrey;
}
footer p { margin: 0; }