diff --git a/src/App.vue b/src/App.vue
index 3548954..3a46f82 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -1,19 +1,23 @@
 <script setup lang="ts">
-import { ref, onMounted, defineAsyncComponent } from "vue";
+import { ref, onMounted, onErrorCaptured, defineAsyncComponent } from "vue";
 import { useAppStore } from "@/stores/app.store";
 import UnlockLayout from "@/layouts/UnlockLayout.vue";
 
-const MainLayout = defineAsyncComponent(
-  () => import("@/layouts/MainLayout.vue")
-);
-const ToolWindow = defineAsyncComponent(
-  () => import("@/components/tools/ToolWindow.vue")
-);
-const DetachedSession = defineAsyncComponent(
-  () => import("@/components/session/DetachedSession.vue")
-);
+const MainLayout = defineAsyncComponent({
+  loader: () => import("@/layouts/MainLayout.vue"),
+  onError(error) { console.error("[App] MainLayout load failed:", error); },
+});
+const ToolWindow = defineAsyncComponent({
+  loader: () => import("@/components/tools/ToolWindow.vue"),
+  onError(error) { console.error("[App] ToolWindow load failed:", error); },
+});
+const DetachedSession = defineAsyncComponent({
+  loader: () => import("@/components/session/DetachedSession.vue"),
+  onError(error) { console.error("[App] DetachedSession load failed:", error); },
+});
 
 const app = useAppStore();
+const appError = ref<string | null>(null);
 
 // Tool window mode — detected from URL hash: #/tool/network-scanner?sessionId=abc
 const isToolMode = ref(false);
@@ -21,6 +25,12 @@ const isDetachedMode = ref(false);
 const toolName = ref("");
 const toolSessionId = ref("");
 
+onErrorCaptured((err) => {
+  appError.value = err instanceof Error ? err.message : String(err);
+  console.error("[App] Uncaught error:", err);
+  return false;
+});
+
 onMounted(async () => {
   const hash = window.location.hash;
   if (hash.startsWith("#/tool/")) {
@@ -38,8 +48,12 @@ onMounted(async () => {
 </script>
 
 <template>
+  <!-- Error display for debugging -->
+  <div v-if="appError" class="fixed inset-0 z-50 flex items-center justify-center bg-[#0d1117] text-red-400 p-8 text-sm font-mono whitespace-pre-wrap">
+    {{ appError }}
+  </div>
   <!-- Detached session window mode -->
-  <DetachedSession v-if="isDetachedMode" />
+  <DetachedSession v-else-if="isDetachedMode" />
   <!-- Tool popup window mode -->
   <ToolWindow v-else-if="isToolMode" :tool="toolName" :session-id="toolSessionId" />
   <!-- Normal app mode -->
diff --git a/src/components/terminal/LocalTerminalView.vue b/src/components/terminal/LocalTerminalView.vue
index e27f347..0e221e5 100644
--- a/src/components/terminal/LocalTerminalView.vue
+++ b/src/components/terminal/LocalTerminalView.vue
@@ -33,9 +33,9 @@ function applyTheme(): void {
     foreground: theme.foreground,
     cursor: theme.cursor,
     cursorAccent: theme.background,
-    selectionBackground: theme.selectionBackground ?? "rgba(88, 166, 255, 0.4)",
+    selectionBackground: theme.selectionBackground ?? "#264f78",
     selectionForeground: theme.selectionForeground ?? "#ffffff",
-    selectionInactiveBackground: theme.selectionBackground ?? "rgba(88, 166, 255, 0.2)",
+    selectionInactiveBackground: theme.selectionBackground ?? "#264f78",
     black: theme.black,
     red: theme.red,
     green: theme.green,
diff --git a/src/components/terminal/TerminalView.vue b/src/components/terminal/TerminalView.vue
index cfe5e85..f107d83 100644
--- a/src/components/terminal/TerminalView.vue
+++ b/src/components/terminal/TerminalView.vue
@@ -77,6 +77,10 @@ const containerRef = ref<HTMLElement | null>(null);
 const { terminal, searchAddon, mount, fit } = useTerminal(props.sessionId);
 let resizeDisposable: IDisposable | null = null;
 
+function handleFocus(): void {
+  terminal.focus();
+}
+
 // --- Search state ---
 const searchVisible = ref(false);
 const searchQuery = ref("");
@@ -152,10 +156,6 @@ onMounted(() => {
   }, 50);
 });
 
-function handleFocus(): void {
-  terminal.focus();
-}
-
 // Re-fit and focus terminal when switching back to this tab.
 // Must wait for the container to have real dimensions after becoming visible.
 watch(
@@ -190,9 +190,9 @@ function applyTheme(): void {
     foreground: theme.foreground,
     cursor: theme.cursor,
     cursorAccent: theme.background,
-    selectionBackground: theme.selectionBackground ?? "rgba(88, 166, 255, 0.4)",
+    selectionBackground: theme.selectionBackground ?? "#264f78",
     selectionForeground: theme.selectionForeground ?? "#ffffff",
-    selectionInactiveBackground: theme.selectionBackground ?? "rgba(88, 166, 255, 0.2)",
+    selectionInactiveBackground: theme.selectionBackground ?? "#264f78",
     black: theme.black,
     red: theme.red,
     green: theme.green,
diff --git a/src/composables/useTerminal.ts b/src/composables/useTerminal.ts
index aaa053f..48b256a 100644
--- a/src/composables/useTerminal.ts
+++ b/src/composables/useTerminal.ts
@@ -14,8 +14,9 @@ const defaultTheme = {
   foreground: "#e0e0e0",
   cursor: "#58a6ff",
   cursorAccent: "#0d1117",
-  selectionBackground: "rgba(88, 166, 255, 0.4)",
+  selectionBackground: "#264f78",
   selectionForeground: "#ffffff",
+  selectionInactiveBackground: "#264f78",
   black: "#0d1117",
   red: "#f85149",
   green: "#3fb950",