diff --git a/main.go b/main.go
index c2757d5..55c14bb 100644
--- a/main.go
+++ b/main.go
@@ -199,6 +199,7 @@ type appState struct {
 	compareFile1     *videoSource
 	compareFile2     *videoSource
 	keyframingMode   bool // Toggle for frame-accurate editing features
+	isFullscreen     bool // Fullscreen mode state
 }
 
 func (s *appState) stopPreview() {
@@ -208,6 +209,11 @@ func (s *appState) stopPreview() {
 	}
 }
 
+func (s *appState) toggleFullscreen() {
+	s.isFullscreen = !s.isFullscreen
+	s.window.SetFullScreen(s.isFullscreen)
+}
+
 func (s *appState) updateStatsBar() {
 	if s.statsBar == nil || s.jobQueue == nil {
 		return
@@ -2024,6 +2030,19 @@ func runGUI() {
 	w.SetOnDropped(func(pos fyne.Position, items []fyne.URI) {
 		state.handleDropPlayer(items)
 	})
+
+	// Global keyboard shortcuts (F11 for fullscreen, ESC to exit fullscreen)
+	w.Canvas().SetOnTypedKey(func(key *fyne.KeyEvent) {
+		switch key.Name {
+		case fyne.KeyF11:
+			state.toggleFullscreen()
+		case fyne.KeyEscape:
+			if state.isFullscreen {
+				state.toggleFullscreen()
+			}
+		}
+	})
+
 	state.showMainMenu()
 	logging.Debug(logging.CatUI, "main menu rendered with %d modules", len(modulesList))
 
diff --git a/scripts/build.sh.old b/scripts/build.sh.old
new file mode 100755
index 0000000..b66c98e
--- /dev/null
+++ b/scripts/build.sh.old
@@ -0,0 +1,63 @@
+#!/bin/bash
+# VT Player Build Script
+# Cleans dependencies and builds the application with proper error handling
+
+set -e
+
+PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+BUILD_OUTPUT="$PROJECT_ROOT/VTPlayer"
+
+echo "════════════════════════════════════════════════════════════════"
+echo "  VT Player Build Script"
+echo "════════════════════════════════════════════════════════════════"
+echo ""
+
+# Check if go is installed
+if ! command -v go &> /dev/null; then
+    echo "❌ ERROR: Go is not installed. Please install Go 1.21 or later."
+    exit 1
+fi
+
+echo "📦 Go version:"
+go version
+echo ""
+
+# Change to project directory
+cd "$PROJECT_ROOT"
+
+echo "🧹 Cleaning previous builds and cache..."
+go clean -cache -modcache -testcache 2>/dev/null || true
+rm -f "$BUILD_OUTPUT" 2>/dev/null || true
+echo "✓ Cache cleaned"
+echo ""
+
+echo "⬇️  Downloading and verifying dependencies..."
+go mod download
+go mod verify
+echo "✓ Dependencies verified"
+echo ""
+
+echo "🔨 Building VT Player..."
+# Fyne needs cgo for GLFW/OpenGL bindings; build with CGO enabled.
+export CGO_ENABLED=1
+if go build -o "$BUILD_OUTPUT" .; then
+    echo "✓ Build successful!"
+    echo ""
+    echo "════════════════════════════════════════════════════════════════"
+    echo "✅ BUILD COMPLETE"
+    echo "════════════════════════════════════════════════════════════════"
+    echo ""
+    echo "Output: $BUILD_OUTPUT"
+    echo "Size: $(du -h "$BUILD_OUTPUT" | cut -f1)"
+    echo ""
+    echo "To run:"
+    echo "  $PROJECT_ROOT/VTPlayer"
+    echo ""
+    echo "Or use the convenience script:"
+    echo "  source $PROJECT_ROOT/scripts/alias.sh"
+    echo "  VTPlayer"
+    echo ""
+else
+    echo "❌ Build failed!"
+    exit 1
+fi