diff --git a/client/build.sh b/client/build.sh
index d2e89bf..ba28ada 100755
--- a/client/build.sh
+++ b/client/build.sh
@@ -5,7 +5,7 @@ set -e
 cd "$(dirname "$0")"
 
 echo "============================================="
-echo "   BUILDING SECURE WAILS CLIENT FOR MACOS    "
+echo "        BUILDING SECURE WAILS CLIENT         "
 echo "============================================="
 
 # Setup Go path for tools like garble and wails
@@ -46,10 +46,21 @@ else
 fi
 BUILD_FLAGS+=(-ldflags "-s -w")
 
-echo "[*] Building macOS Apple Silicon (arm64)..."
-"$WAILS_CMD" build -platform darwin/arm64 "${BUILD_FLAGS[@]}"
+# Detect host OS
+HOST_OS=$(go env GOOS)
 
-echo "[*] Building macOS Intel (amd64)..."
-"$WAILS_CMD" build -platform darwin/amd64 "${BUILD_FLAGS[@]}"
+if [ "$HOST_OS" = "darwin" ]; then
+    echo "[*] Building macOS Apple Silicon (arm64)..."
+    "$WAILS_CMD" build -platform darwin/arm64 "${BUILD_FLAGS[@]}"
 
-echo "[+] macOS arm64 and amd64 builds completed successfully!"
+    echo "[*] Building macOS Intel (amd64)..."
+    "$WAILS_CMD" build -platform darwin/amd64 "${BUILD_FLAGS[@]}"
+    echo "[+] macOS arm64 and amd64 builds completed successfully!"
+elif [ "$HOST_OS" = "linux" ]; then
+    echo "[*] Building Linux Intel/AMD64 (amd64)..."
+    "$WAILS_CMD" build -platform linux/amd64 -tags webkit2_41 "${BUILD_FLAGS[@]}"
+    echo "[+] Linux amd64 build completed successfully!"
+else
+    echo "[!] Unsupported host OS: $HOST_OS. Please build manually using 'wails build'."
+    exit 1
+fi
diff --git a/client/build/trim.txt b/client/build/trim.txt
new file mode 100644
index 0000000..63746f1
--- /dev/null
+++ b/client/build/trim.txt
@@ -0,0 +1 @@
+1782971860
\ No newline at end of file
diff --git a/client/internal/blocker/blocker_linux.go b/client/internal/blocker/blocker_linux.go
new file mode 100644
index 0000000..f026d6a
--- /dev/null
+++ b/client/internal/blocker/blocker_linux.go
@@ -0,0 +1,214 @@
+//go:build linux
+
+package blocker
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+var systemAllowed = map[string]bool{
+	"gnome-shell":        true,
+	"mutter":             true,
+	"xterm":              true,
+	"gnome-terminal":     true,
+	"konsole":            true,
+	"ptyxis":             true, // Ubuntu terminal
+	"bash":               true,
+	"zsh":                true,
+	"sh":                 true,
+	"wails":              true,
+	"code":               true,
+	"cursor":             true,
+	"windsurf":           true,
+	"goland":             true,
+	"idea":               true,
+	"client":             true,
+	"simple_care_v1.0":   true,
+	"xwayland":           true,
+	"mutter-x11-fram":    true,
+	"ibus-x11":           true,
+	"ibus-daemon":        true,
+	"gsd-":               true, // prefix
+	"ibus-":              true, // prefix
+	"xdg-":               true, // prefix
+	"at-spi":             true, // prefix
+	"evolution-":         true, // prefix
+	"goa-daemon":         true,
+	"gjs":                true,
+	"snapd-":             true, // prefix
+	"systemd":            true,
+	"webkit":             true, // WebKit subprocesses
+	"glycin":             true, // GNOME image helper
+	"zenity":             true, // Dialog utility
+	"rustdesk":           true, // Remote support safety
+	"rustdesk-bin":       true,
+	"anydesk":            true,
+	"teamviewer":         true,
+	"remmina":            true,
+}
+
+func isSystemAllowed(name string) bool {
+	name = strings.ToLower(name)
+	if systemAllowed[name] {
+		return true
+	}
+	for pattern := range systemAllowed {
+		if strings.HasPrefix(name, pattern) && pattern != name {
+			return true
+		}
+	}
+	return false
+}
+
+func getPPID(pid uint32) uint32 {
+	statusBytes, err := os.ReadFile(fmt.Sprintf("/proc/%d/status", pid))
+	if err != nil {
+		return 0
+	}
+	lines := strings.Split(string(statusBytes), "\n")
+	for _, line := range lines {
+		if strings.HasPrefix(line, "PPid:") {
+			parts := strings.Fields(line)
+			if len(parts) >= 2 {
+				if ppid, err := strconv.ParseUint(parts[1], 10, 32); err == nil {
+					return uint32(ppid)
+				}
+			}
+		}
+	}
+	return 0
+}
+
+func isDescendantOf(pid, targetPid uint32) bool {
+	curr := pid
+	for i := 0; i < 10; i++ { // limits lookup to 10 ancestor levels
+		ppid := getPPID(curr)
+		if ppid == 0 {
+			return false
+		}
+		if ppid == targetPid {
+			return true
+		}
+		curr = ppid
+	}
+	return false
+}
+
+type ProcessInfo struct {
+	PID  uint32
+	Name string
+}
+
+func getVisibleProcesses() (map[uint32]ProcessInfo, error) {
+	files, err := os.ReadDir("/proc")
+	if err != nil {
+		return nil, err
+	}
+
+	procs := make(map[uint32]ProcessInfo)
+	for _, f := range files {
+		if !f.IsDir() {
+			continue
+		}
+		pid, err := strconv.ParseUint(f.Name(), 10, 32)
+		if err != nil {
+			continue
+		}
+
+		mapsPath := fmt.Sprintf("/proc/%d/maps", pid)
+		mapsBytes, err := os.ReadFile(mapsPath)
+		if err != nil {
+			// Skip processes we don't own (permission denied)
+			continue
+		}
+
+		mapsStr := string(mapsBytes)
+		isGUI := strings.Contains(mapsStr, "libgtk") ||
+			strings.Contains(mapsStr, "libQt") ||
+			strings.Contains(mapsStr, "libX11") ||
+			strings.Contains(mapsStr, "libwayland-client")
+
+		if !isGUI {
+			continue
+		}
+
+		// Read process name from /proc/PID/comm
+		commBytes, err := os.ReadFile(fmt.Sprintf("/proc/%d/comm", pid))
+		if err != nil {
+			continue
+		}
+		procName := strings.TrimSpace(string(commBytes))
+
+		if procName != "" {
+			procs[uint32(pid)] = ProcessInfo{
+				PID:  uint32(pid),
+				Name: procName,
+			}
+		}
+	}
+
+	return procs, nil
+}
+
+func (b *Blocker) checkAndKill() {
+	b.mu.Lock()
+	keywords := make([]string, len(b.allowedKeywords))
+	copy(keywords, b.allowedKeywords)
+	b.mu.Unlock()
+
+	if len(keywords) == 0 {
+		return
+	}
+
+	currentExec := ""
+	if execPath, err := os.Executable(); err == nil {
+		currentExec = strings.ToLower(filepath.Base(execPath))
+	}
+
+	procs, err := getVisibleProcesses()
+	if err != nil {
+		log.Printf("[BLOCKER] Failed to get visible processes: %v", err)
+		return
+	}
+
+	myPid := uint32(os.Getpid())
+	for pid, info := range procs {
+		pNameLower := strings.ToLower(info.Name)
+
+		// 1. Always allow our app, our sub-processes, system/critical developer tools, or agent helpers
+		isOurSubprocess := pid == myPid || isDescendantOf(pid, myPid)
+		isAntigravity := strings.Contains(pNameLower, "antigravity")
+		if isOurSubprocess || (currentExec != "" && pNameLower == currentExec) || isSystemAllowed(pNameLower) || isAntigravity {
+			continue
+		}
+
+		// 2. Check if the process name contains any allowed keywords
+		allowed := false
+		for _, kw := range keywords {
+			if matchesAllowedKeyword(kw, pNameLower, pNameLower) {
+				allowed = true
+				break
+			}
+		}
+
+		// 3. If not allowed, kill the application
+		if !allowed {
+			if b.OnBlocked != nil {
+				b.OnBlocked(info.Name, info.Name)
+			}
+			log.Printf("[BLOCKER] KILLED unauthorized application: %s (PID: %d)", info.Name, pid)
+			proc, err := os.FindProcess(int(pid))
+			if err == nil {
+				errKill := proc.Kill()
+				if errKill == nil && b.OnKill != nil {
+					b.OnKill(info.Name, info.Name)
+				}
+			}
+		}
+	}
+}
diff --git a/client/internal/blocker/blocker_other.go b/client/internal/blocker/blocker_other.go
index 8a28577..7d7fd0e 100644
--- a/client/internal/blocker/blocker_other.go
+++ b/client/internal/blocker/blocker_other.go
@@ -1,4 +1,4 @@
-//go:build !windows && !darwin
+//go:build !windows && !darwin && !linux
 
 package blocker
 
diff --git a/client/internal/guard/guard_linux.go b/client/internal/guard/guard_linux.go
new file mode 100644
index 0000000..4eda870
--- /dev/null
+++ b/client/internal/guard/guard_linux.go
@@ -0,0 +1,90 @@
+//go:build linux
+
+package guard
+
+import (
+	"sync"
+	"time"
+
+	"github.com/kbinani/screenshot"
+)
+
+var (
+	guardOnce               sync.Once
+	guardViolation          func(string)
+	guardStop               chan struct{}
+	suppressMu              sync.Mutex
+	suppressViolationsUntil time.Time
+)
+
+// SuppressFor temporarily suspends environment violation checks (e.g. when transition screen)
+func SuppressFor(d time.Duration) {
+	if d <= 0 {
+		return
+	}
+	suppressMu.Lock()
+	next := time.Now().Add(d)
+	if next.After(suppressViolationsUntil) {
+		suppressViolationsUntil = next
+	}
+	suppressMu.Unlock()
+}
+
+func violationsSuppressed() bool {
+	suppressMu.Lock()
+	defer suppressMu.Unlock()
+	return time.Now().Before(suppressViolationsUntil)
+}
+
+// Start monitors the Linux desktop environment (multi-display check)
+func Start(onViolation func(reason string)) {
+	guardOnce.Do(func() {
+		if onViolation == nil {
+			return
+		}
+		guardViolation = onViolation
+		guardStop = make(chan struct{})
+
+		if screenshot.NumActiveDisplays() > 1 {
+			onViolation("Phát hiện nhiều hơn 1 màn hình. Vui lòng chỉ dùng một màn hình khi chạy Simple Care.")
+			return
+		}
+
+		go pollLoop()
+	})
+}
+
+// Stop stops the environment guard
+func Stop() {
+	if guardStop != nil {
+		select {
+		case <-guardStop:
+			// already closed
+		default:
+			close(guardStop)
+		}
+	}
+}
+
+func pollLoop() {
+	ticker := time.NewTicker(3 * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-guardStop:
+			return
+		case <-ticker.C:
+			checkEnvironment()
+		}
+	}
+}
+
+func checkEnvironment() {
+	if guardViolation == nil || violationsSuppressed() {
+		return
+	}
+	if n := screenshot.NumActiveDisplays(); n > 1 {
+		guardViolation("Phát hiện nhiều hơn 1 màn hình. Vui lòng rút/bật tắt màn hình phụ.")
+		return
+	}
+}
diff --git a/client/internal/guard/guard_other.go b/client/internal/guard/guard_other.go
index e5fce7b..74d99a6 100644
--- a/client/internal/guard/guard_other.go
+++ b/client/internal/guard/guard_other.go
@@ -1,4 +1,4 @@
-//go:build !windows && !darwin
+//go:build !windows && !darwin && !linux
 
 package guard
 
diff --git a/client/internal/winapi/window_linux.go b/client/internal/winapi/window_linux.go
new file mode 100644
index 0000000..22422e4
--- /dev/null
+++ b/client/internal/winapi/window_linux.go
@@ -0,0 +1,40 @@
+//go:build linux
+
+package winapi
+
+import (
+	"log"
+	"os/exec"
+)
+
+// ActivateAppWindow attempts to focus the application window.
+// On Linux standard X11/Wayland desktop, focus is managed by the WM.
+func ActivateAppWindow(titleHint string) {
+	log.Printf("[WINDOW] ActivateAppWindow requested for: %s", titleHint)
+}
+
+// PlayNotifySound plays a system notification sound using canberra-gtk-play, falling back to pw-play or aplay.
+func PlayNotifySound() {
+	log.Println("[WINDOW] Playing notification sound...")
+	go func() {
+		// Try canberra-gtk-play first
+		cmd := exec.Command("canberra-gtk-play", "-i", "bell")
+		if err := cmd.Run(); err != nil {
+			// Fallback to pw-play (Pipewire)
+			cmd = exec.Command("pw-play", "/usr/share/sounds/freedesktop/stereo/bell.oga")
+			if err := cmd.Run(); err != nil {
+				// Fallback to aplay (ALSA)
+				_ = exec.Command("aplay", "/usr/share/sounds/alsa/Front_Center.wav").Run()
+			}
+		}
+	}()
+}
+
+// ShowWarningMessageBox displays an asynchronous GUI warning dialog using zenity.
+func ShowWarningMessageBox(title, message string) {
+	log.Printf("[WINDOW] Warning Message Box: %s - %s", title, message)
+	go func() {
+		cmd := exec.Command("zenity", "--warning", "--title="+title, "--text="+message, "--no-wrap")
+		_ = cmd.Run()
+	}()
+}
diff --git a/client/internal/winapi/window_other.go b/client/internal/winapi/window_other.go
index f751ad3..41d8927 100644
--- a/client/internal/winapi/window_other.go
+++ b/client/internal/winapi/window_other.go
@@ -1,4 +1,4 @@
-//go:build !windows && !darwin
+//go:build !windows && !darwin && !linux
 
 package winapi