feat: grey out broken links

Jacky Zhao

2022-04-02 c51573efa98de6b5b5e79fb60b49f31daca70527

 assets/styles/base.scss

@@ -185,6 +185,11 @@
      padding: 0 0.1em;
      margin: auto -0.1em;
      border-radius: 3px;

      &.broken {
        opacity: 0.5;
        background-color: transparent; 
      }
    }
  }