fix: explicit undefined check in header transclude

Jacky Zhao

2023-11-19 516d9a27e7e2c08efdf24857b03f1831dbaf7da7

 quartz/styles/base.scss

@@ -64,7 +64,7 @@
    color: var(--tertiary) !important;
  }

  &.internal {
  &.internal:not(:has(> img)) {
    text-decoration: none;
    background-color: var(--highlight);
    padding: 0 0.1rem;