How to customize your Transistor.fm Website with JS and CSS

<script>
window.onload = function () {
  let el;
  if (document.location.pathname === "/episodes") {
    el = document.createElement("div");
    document
      .getElementsByClassName("site-content")[0]
      .parentNode.insertBefore(
        el,
        document.getElementsByClassName("site-content")[0]
      );
  } else {
    // assuming index page
    el = document.getElementsByClassName("site-first-episode")[0];
  }

  el.innerHTML = `
<iframe title="swyx mixtape embed" width="100%" height="390" frameborder="no" scrolling="no" seamless src="https://share.transistor.fm/e/learn-in-podcast/playlist/dark"></iframe>
`;
  el.id = "swyxembed";
};
function makeLive() {
  if (!document.getElementById("swyxembed")) window.onload();
  setTimeout(makeLive, 200);
}
setTimeout(makeLive, 200);
</script>

.site-intro {
     font-size: 1.25rem;
     width: 60ch;
     margin: 0 auto;
}
 .site-credits {
     position: fixed;
     width: 100vw;
     bottom: 0;
}
 #site-footer {
     display: hidden 
}
 #swyxembed {
     padding: 2rem;
}
 .site-featured-episodes .site-episode {
     display: block;
}
 .site-episode {
     display: grid;
     grid-template-areas: "date title" "date desc";
     grid-template-rows: minmax(1rem, auto) 1fr;
     grid-template-columns: 10ch 1fr;
     grid-column-gap: 1rem;
     margin-bottom: 1rem;
}
 .site-episode time {
     grid-area: date 
}
 .site-episode time span {
     text-transform: none 
}
 .site-episode h2 {
     grid-area: title;
     font-size: 1.5rem 
}
 .site-episode .site-episode-summary {
     grid-area: desc 
}
 .site-episode nav {
     display: none;
}