.brx-tabs-nav { position: relative; display: flex; }  .brx-tabs-nav::after { content: ""; position: absolute; bottom: 0; left: 0; height: 3px;  width: var(--indicator-width, 0px);  background: #0ea5e9;  transform: translateX(var(--indicator-x, 0px)); transition: transform 0.3s ease, width 0.3s ease; border-radius: 2px; }