Add min-height for line to address rendering issue for empty lines at EOF

Author: jwl-7

src/components/Code/code.module.sass

@@ -13,6 +13,7 @@
     display: block
     border-left: 0.5px solid var(--code-line-number-color)
     padding-left: 1em
+    min-height: 1em
 
     &::before
         content: attr(data-line-number)