fix: add working close button and backdrop for mobile sideba

- Add close (X) button and backdrop overlay markup to #mainSidebar
- Style new elements, scoped to mobile via media query
- Wire close button, backdrop click, and Escape key to remove
  body.sidebar-active, which is the class actually controlling
  sidebar visibility (previous mobileSidebarToggle JS referenced
  a button that didn't exist in the markup, so the sidebar had
  no way to be dismissed once opened)

Author: dev-2006-prt

web-app/css/styles.css

@@ -6394,3 +6394,41 @@ body.sidebar-collapsed .projects-section {
   padding-right: 0 !important;
 }
 }
+
+.sidebar-mobile-close {
+  display: none;
+  position: absolute;
+  top: 16px;
+  right: 16px;
+  width: 36px;
+  height: 36px;
+  border: none;
+  border-radius: 50%;
+  background: var(--bg-glass);
+  color: var(--text-primary);
+  font-size: 16px;
+  align-items: center;
+  justify-content: center;
+  cursor: pointer;
+  z-index: 1001;
+}
+.sidebar-backdrop {
+  display: none;
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.5);
+  z-index: 999;
+  opacity: 0;
+  transition: opacity 0.3s ease;
+  pointer-events: none;
+}
+@media (max-width: 768px) {
+  .sidebar-mobile-close {
+    display: flex;
+  }
+  body.sidebar-active .sidebar-backdrop {
+    display: block;
+    opacity: 1;
+    pointer-events: auto;
+  }
+}

web-app/index.html

@@ -95,6 +95,14 @@
     </nav>
 
     <aside class="sidebar-dock" id="mainSidebar">
+      <button
+  class="sidebar-mobile-close"
+  id="sidebarMobileClose"
+  aria-label="Close sidebar"
+  type="button"
+>
+  <i class="fas fa-times" aria-hidden="true"></i>
+</button>
       <div class="sidebar-search">
         <div class="search-box" style="position: relative">
           <i class="fas fa-search" aria-hidden="true"></i>
@@ -261,6 +269,7 @@
         </div>
       </div>
     </aside>
+    <div class="sidebar-backdrop" id="sidebarBackdrop"></div>
 
     <main id="main-content" tabindex="-1">
       <!-- Hero Section -->

web-app/js/main.js

@@ -350,32 +350,29 @@ document.addEventListener("DOMContentLoaded", function () {
     });
   }
 
-  /* ── Mobile Sidebar Toggle ──────────────────────────────── */
-  var mobileSidebarToggle = document.getElementById("mobileSidebarToggle");
+  /* ── Mobile Sidebar Close ──────────────────────────────── */
   var mainSidebar = document.getElementById("mainSidebar");
-  if (mobileSidebarToggle && mainSidebar) {
-    mobileSidebarToggle.addEventListener("click", function () {
-      var active = mainSidebar.classList.toggle("open");
-      mobileSidebarToggle.setAttribute("aria-expanded", active);
-      var icon = mobileSidebarToggle.querySelector("i");
-      if (icon) icon.className = active ? "fas fa-times" : "fas fa-bars";
-    });
+  var sidebarMobileClose = document.getElementById("sidebarMobileClose");
+  var sidebarBackdrop = document.getElementById("sidebarBackdrop");
 
-    document.addEventListener("click", function (e) {
-      if (
-        mainSidebar &&
-        mobileSidebarToggle &&
-        !mainSidebar.contains(e.target) &&
-        e.target !== mobileSidebarToggle &&
-        mainSidebar.classList.contains("open")
-      ) {
-        mainSidebar.classList.remove("open");
-        mobileSidebarToggle.setAttribute("aria-expanded", "false");
-        var icon = mobileSidebarToggle.querySelector("i");
-        if (icon) icon.className = "fas fa-bars";
-      }
-    });
+  function closeMobileSidebar() {
+    document.body.classList.remove("sidebar-active");
+  }
+
+  if (sidebarMobileClose) {
+    sidebarMobileClose.addEventListener("click", closeMobileSidebar);
   }
+  if (sidebarBackdrop) {
+    sidebarBackdrop.addEventListener("click", closeMobileSidebar);
+  }
+  document.addEventListener("keydown", function (e) {
+    if (
+      e.key === "Escape" &&
+      document.body.classList.contains("sidebar-active")
+    ) {
+      closeMobileSidebar();
+    }
+  });
 
   /* ── Desktop Sidebar Toggle ──────────────────────────────── */
   var desktopSidebarToggle = document.getElementById("sidebarCollapseBtn");