设置顶部边框样式 - 在线编辑器

          <!DOCTYPE html>
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    p {
      border-style: solid;
    }

    p.none {
      border-top-style: none;
    }

    p.dotted {
      border-top-style: dotted;
    }

    p.dashed {
      border-top-style: dashed;
    }

    p.solid {
      border-top-style: solid;
    }

    p.double {
      border-top-style: double;
    }

    p.groove {
      border-top-style: groove;
    }

    p.ridge {
      border-top-style: ridge;
    }

    p.inset {
      border-top-style: inset;
    }

    p.outset {
      border-top-style: outset;
    }
  </style>
</head>

<body>
  <p class="none">无上底边界。</p>
  <p class="dotted">点上底边界。</p>
  <p class="dashed">虚线上底边界。</p>
  <p class="solid">实线上底边界。</p>
  <p class="double">双线上底边界。</p>
  <p class="groove">凹槽上底边界。</p>
  <p class="ridge">垄状上底边界。</p>
  <p class="inset">嵌入上底边界。</p>
  <p class="outset">外凸上底边界。</p>
</body>
</html>
        