Add list dynamic background

static/main.js

@@ -0,0 +1,24 @@
+hljs.initHighlightingOnLoad();
+
+const listBg = document.querySelector('.list-bg');
+
+if (listBg) {
+  const halfAnHour = 1000 * 60 * 30;
+
+  function setListBgStyle() {
+    const now = new Date();
+    const time = now.getHours() + now.getMinutes() / 60;
+
+    let opacity = Math.abs(time - 14);
+    opacity = opacity > 12 ? 10 + Math.abs(opacity - 14) : opacity;
+    opacity = Number((opacity / 12).toFixed(2));
+
+    listBg.setAttribute('style', `opacity: ${opacity}`);
+  }
+
+  requestAnimationFrame(setListBgStyle);
+
+  setInterval(() => {
+    requestAnimationFrame(setListBgStyle);
+  }, halfAnHour);
+}