This is awesome!
I recently did a similar project with Remix & the Hashnode API. To get the syntax highlighting to work, I used PrismJS and this highlighting theme.
Your site looks great!
<head>
<link rel="stylesheet" href="./src/styles/prism-material-oceanic.min-KZVM6LVB.css">
</head>
<body>
...
<script src="cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/prism…/>
<script src="cdnjs.cloudflare.com/ajax/libs/prism/1.26.0/plugi…/>
</body>