.tab-pane ul {
    margin: 0px;
    padding: 0px;
}
.tab-pane .formula-latex-item {
    display: inline-block;
    margin: 0px 3px 3px 0px;
    width: 30px;
    height: 30px;
    border:1px solid #cccccc;
    background-image: url("./images/formula.png");
    cursor: pointer;
}