.ChatBox {
    display: flex;
    flex-flow: column;
    margin: 5px;
    padding: 5px;
    background-color: azure;
    border-radius: 4px;
    height: 85%;
}

.ChatBoxHeader {
    flex: 0 1 auto;
}

.ChatBoxContent {
    flex: 1 1 auto;
    overflow-y: scroll;
}

.ChatBoxFooter {
    flex: 0 1 0px;
}