Module:Message box/style.css

.box {
    border: solid black 1px;
    border-left: solid black 10px;
    display: flex;
    flex-direction: row;
    justify-content: flex-start;
}

.box span {
    display: flex;
    flex-direction: column;
    justify-content: center;
    margin-left: 10px;
}