hydrogen-web/src/ui/web/css/room.css

.RoomHeader {
    padding: 10px;
    background-color: #333;
}

.RoomHeader *:last-child {
    margin-right: 0 !important;
}

.RoomHeader > * {
    margin-right: 10px !important;
}

.RoomHeader button {
    width: 40px;
    height: 40px;
    display: none;
    font-size: 1.5em;
    padding: 0;
    display: block;
    background: white;
    border: none;
    font-weight: bolder;
    line-height: 40px;
}

.RoomHeader button.back {
    display: none;
}

.RoomHeader .topic {
    font-size: 0.8em;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
}

.back::before {
    content: "☰";
}

.more::before {
    content: "⋮";
}

.RoomHeader {
    align-items: center;
}

.RoomHeader .description {
    flex: 1 1 auto;
    min-width: 0;
}

.RoomHeader h2 {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    margin: 0;
}

.RoomView_error {
    color: red;
}