fix(darkmode): check for null (#1531)

Francisco Gama T. R.

2024-12-03 5a5ef670fee5f5f65981801a7ec9c2e563fe99ad

 quartz/components/styles/legacyToc.scss

@@ -12,7 +12,7 @@
      margin: 0;
    }
  }
    

  & ul {
    list-style: none;
    margin: 0.5rem 1.25rem;