.fme-custom-message {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    box-sizing: border-box;
    width: 100%;
    margin: 0 0 12px;
    padding: 10px 16px;
    border: 1px solid transparent;
    border-radius: 5px;
}
.fme-custom-message-icon {
    flex: none;
    width: 40px;
    height: 40px;
    border-radius: 5px;
}
.fme-custom-message-text { flex: 1 1 240px; min-width: 0; }
.fme-custom-message-button,
.fme-custom-message-button:visited,
.fme-custom-message-button:hover {
    flex: none;
    padding: 9px 18px;
    border-radius: 5px;
    font-weight: 600;
    text-decoration: none;
}

/* Luma lifts the Sign In link up beside the mini cart with a negative margin. Below a message it would land inside the box. */
.fme-custom-message ~ #checkout .authentication-wrapper { margin-top: 0; }