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* fix outdated code and broken components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/css/navigation.css

@@ -0,0 +1,43 @@
+.header {
+  @apply bg-body  py-6;
+}
+
+/* navbar items */
+.navbar {
+  @apply relative flex flex-wrap items-center justify-between;
+}
+
+.navbar-brand {
+  @apply text-text-dark  text-xl font-semibold;
+  image {
+    @apply max-h-full max-w-full;
+  }
+}
+
+.navbar-nav {
+  @apply text-center lg:text-left;
+}
+
+.nav-link {
+  @apply text-text-dark hover:text-primary block p-3 cursor-pointer font-semibold transition lg:px-2 lg:py-3;
+}
+
+.nav-dropdown {
+  @apply mr-0;
+}
+
+.nav-dropdown > svg {
+  @apply pointer-events-none;
+}
+
+.nav-dropdown-list {
+  @apply bg-body  z-10 min-w-[180px] rounded p-4 shadow-sm;
+}
+
+.nav-dropdown-item {
+  @apply [&:not(:last-child)]:mb-2;
+}
+
+.nav-dropdown-link {
+  @apply text-text-dark hover:text-primary   block py-1 font-semibold transition;
+}