feat: migrate Hugo Bootstrap theme to latest Hugo with Tailwind CSS and refactor codebase

* replace Bootstrap-based styling with Tailwind CSS
* update theme compatibility for latest Hugo version
* refactor templates and partials
* fix outdated code and broken components
* improve project structure and maintainability
* optimize styling and frontend build setup

assets/js/main.js

@@ -0,0 +1,43 @@
+// main script
+(function () {
+  "use strict";
+
+  // Header shrink on scroll
+  (function () {
+    var header = document.getElementById("site-header");
+    if (!header) return;
+    // only enable shrink behavior when navbar_fixed param is true
+    var navbarFixed = header.dataset && header.dataset.navbarFixed === "true";
+    if (!navbarFixed) return;
+    var lastKnownScrollY = 0;
+    var ticking = false;
+    var threshold = 20;
+
+    function onScroll() {
+      lastKnownScrollY = window.scrollY || window.pageYOffset;
+      requestTick();
+    }
+
+    function requestTick() {
+      if (!ticking) {
+        requestAnimationFrame(update);
+      }
+      ticking = true;
+    }
+
+    function update() {
+      if (lastKnownScrollY > threshold) {
+        header.classList.add("py-2", "lg:py-3", "shadow-lg");
+        header.classList.remove("py-6", "lg:py-6");
+      } else {
+        header.classList.remove("py-2", "lg:py-3", "shadow-lg");
+        header.classList.add("py-6", "lg:py-6");
+      }
+      ticking = false;
+    }
+
+    window.addEventListener("scroll", onScroll, { passive: true });
+    // run on init
+    update();
+  })();
+})();