mimouchat/srv/public/style.css

body {
    margin: 0;
    padding: 0;
}

.slack-context {
    display: inline-block;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    width: 250px;
    overflow-x: hidden;
    overflow-y: scroll;
}

.slack-chat-container {
    display: inline-block;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 250px;
    right: 0;
}

.slack-context-room.selected {
    background-color: lightgrey;
}