Initial commit.

themes/blowfish/assets/js/background-blur.js

@@ -0,0 +1,10 @@
+(() => {
+  const script = document.currentScript;
+  const targetId = script?.getAttribute("data-target-id");
+
+  window.addEventListener("scroll", () => {
+    const scroll = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
+    const backgroundBlur = document.getElementById(targetId);
+    backgroundBlur.style.opacity = scroll / 300;
+  });
+})();