xmpp.chapril.org-conversejs/sass/converse/_chatbox.scss

#converse-embedded-chat,
#conversejs {
    .chat-head {
        border-top-left-radius: $chatbox-border-radius;
        border-top-right-radius: $chatbox-border-radius;
        @media screen and (max-height: $mobile-landscape-height) {
            border-top-left-radius: 0;
            border-top-right-radius: 0;
        }
        @media screen and (max-width: $mobile-portrait-length) {
            border-top-left-radius: 0;
            border-top-right-radius: 0;
        }
    }
    .chatbox {
        form.sendXMPPMessage {
            .chat-toolbar {
                li {
                    .toolbar-menu {
                        ul {
                            &.emoji-category-picker {
                                display: table;
                                table-layout: fixed;
                                width: 100%;
                                .emoji-category {
                                    display: table-cell;
                                }
                            }
                        }
                    }

                }
            }
        }
    }
}