.manage {
    display: flex;
}
.manage__sidebar {
    flex: 0 0 auto;
    width: 280px;
}
.manage__content {
    flex: 1 1 auto;
}
.manage__description {
    font-size: .9em;
    margin: 1px 2px;
    border-bottom: 1px solid var(--accent-colour);
    padding: 2px 5px;
}

@media (max-width: 800px) {
    .manage {
        flex-direction: column;
    }
    .manage__sidebar {
        width: 100%;
    }
}