CSS-在标签上创建可见边框

Question

使用此处显示的angularJS标签： Example with required solution

我想在标签上添加边框以产生视觉效果。这是我具有以下功能的代码，如果有人知道该怎么做，请告诉我！我认为这是CSS问题，但如果没有，可以更改。

      md-tabs-canvas {
      position: relative;
      overflow: hidden;
      display: block;
      height: 48px; }
      md-tabs-canvas:after {
        content: '';
        display: table;
        clear: both; }
      md-tabs-canvas .md-dummy-wrapper {
        position: absolute;
        top: 0;
        left: 0; }
        [dir=rtl] md-tabs-canvas .md-dummy-wrapper {
          left: auto;
          right: 0; }
      md-tabs-canvas.md-paginated {
        margin: 0 32px; }
      md-tabs-canvas.md-center-tabs {
        display: -webkit-box;
        display: -webkit-flex;
        display: flex;
        -webkit-box-orient: vertical;
        -webkit-box-direction: normal;
        -webkit-flex-direction: column;
                flex-direction: column;
        text-align: center; }
        md-tabs-canvas.md-center-tabs .md-tab {
          float: none;
          display: inline-block; 
        }

      <md-tabs md-stretch-tabs="auto" md-dynamic-height md-border-bottom>
            <md-tab label="User Information">
                <md-content class="md-padding">
                    <div class="col-xs-6 col-md-6">
                        <div class="widget">
                            <div class="widget-header">