Improve zoom handling and setup UI layout

Enhanced zoom target selection to better support parent windows in desktop mode and improved menu popup zoom refresh. Updated setup.css to refine layout, scrolling, and visual effects, including better handling for small screen heights and improved sticky footer appearance.

renderer/menu-popup.js

@@ -35,6 +35,9 @@ window.addEventListener('click', (e) => {
   if (!btn) return;
   const cmd = btn.getAttribute('data-cmd');
   window.electronAPI?.send?.('menu-popup-command', { cmd });
+  if (cmd === 'zoom-in' || cmd === 'zoom-out') {
+    setTimeout(refreshZoom, 50);
+  }
 });
 
 window.addEventListener('keydown', (e) => {

renderer/setup.css

@@ -50,9 +50,10 @@ body, html {
   flex-direction: column;
   align-items: center;
   justify-content: space-between;
+  height: 100vh;
   min-height: 100vh;
   padding: 2rem;
-  overflow-y: auto;
+  overflow: hidden;
 }
 
 /* Progress Bar */
@@ -130,7 +131,7 @@ body, html {
   display: none;
   flex-direction: column;
   align-items: center;
-  justify-content: center;
+  justify-content: flex-start;
   width: 100%;
   max-width: 900px;
   flex: 1;
@@ -159,6 +160,8 @@ body, html {
   margin-bottom: 2rem;
   flex: 1;
   min-height: 0;
+  overflow-y: auto;
+  padding-right: 0.5rem;
 }
 
 .setup-title {
@@ -528,8 +531,8 @@ body, html {
   padding-bottom: 1rem;
   position: sticky;
   bottom: 0;
-  background: transparent;
-  backdrop-filter: none;
+  background: linear-gradient(180deg, rgba(18, 20, 24, 0), rgba(18, 20, 24, 0.85) 45%, rgba(18, 20, 24, 0.95));
+  backdrop-filter: blur(6px);
 }
 
 .btn {
@@ -642,3 +645,21 @@ body, html {
     width: 100%;
   }
 }
+
+@media (max-height: 700px) {
+  .progress-bar {
+    margin-bottom: 1.25rem;
+  }
+
+  .step-content {
+    margin-bottom: 1rem;
+  }
+
+  .setup-subtitle {
+    margin-bottom: 1.25rem;
+  }
+
+  .feature-grid {
+    margin: 1rem 0;
+  }
+}