diff --git a/core/activity_bar.py b/core/activity_bar.py
new file mode 100644
index 0000000..0624ae0
--- /dev/null
+++ b/core/activity_bar.py
@@ -0,0 +1,580 @@
+"""
+EU-Utility - Activity Bar (In-Game Overlay)
+
+macOS-style activity bar/dock for in-game use.
+Features: plugin drawer, mini widgets, floating widgets,
+customizable layout (vertical/horizontal/grid), size, opacity.
+"""
+
+import json
+from pathlib import Path
+from typing import Dict, List, Optional, Callable
+from dataclasses import dataclass, asdict
+from enum import Enum
+
+from PyQt6.QtWidgets import (
+    QWidget, QVBoxLayout, QHBoxLayout, QLabel, QPushButton,
+    QFrame, QScrollArea, QGridLayout, QMenu, QDialog,
+    QSlider, QComboBox, QCheckBox, QSpinBox, QTabWidget
+)
+from PyQt6.QtCore import Qt, QPoint, QSize, QTimer, pyqtSignal
+from PyQt6.QtGui import QMouseEvent, QPainter, QColor, QIcon, QPixmap
+
+
+class ActivityBarLayout(Enum):
+    """Activity bar layout modes."""
+    HORIZONTAL = "horizontal"
+    VERTICAL = "vertical"
+    GRID = "grid"
+
+
+@dataclass
+class ActivityBarConfig:
+    """Activity bar configuration."""
+    enabled: bool = True
+    layout: ActivityBarLayout = ActivityBarLayout.HORIZONTAL
+    position: str = "bottom"  # top, bottom, left, right
+    size: int = 48  # Icon size in pixels
+    opacity: float = 0.9
+    always_visible: bool = False
+    auto_hide: bool = True
+    show_labels: bool = False
+    grid_columns: int = 4  # For grid layout
+    grid_rows: int = 2
+    pinned_plugins: List[str] = None  # Plugin IDs to show in bar
+    
+    def __post_init__(self):
+        if self.pinned_plugins is None:
+            self.pinned_plugins = []
+
+
+class ActivityBar(QFrame):
+    """
+    macOS-style activity bar for in-game overlay.
+    
+    Features:
+    - Plugin drawer (app drawer style)
+    - Pinned plugins in bar
+    - Mini widgets
+    - Configurable layout (horizontal/vertical/grid)
+    - Draggable, resizable
+    - Opacity control
+    """
+    
+    widget_requested = pyqtSignal(str)  # plugin_id
+    drawer_toggled = pyqtSignal(bool)  # is_open
+    
+    def __init__(self, plugin_manager, parent=None):
+        super().__init__(parent)
+        
+        self.plugin_manager = plugin_manager
+        self.config = self._load_config()
+        self.drawer_open = False
+        self.pinned_buttons: Dict[str, QPushButton] = {}
+        self.mini_widgets: Dict[str, QWidget] = {}
+        
+        self._setup_window()
+        self._setup_ui()
+        self._apply_config()
+        
+        # Auto-hide timer
+        self.hide_timer = QTimer(self)
+        self.hide_timer.timeout.connect(self._auto_hide)
+        self.hide_timer.setInterval(3000)  # 3 seconds
+        
+        # Show initially
+        if self.config.enabled:
+            self.show()
+    
+    def _setup_window(self):
+        """Setup window properties for overlay."""
+        self.setWindowFlags(
+            Qt.WindowType.FramelessWindowHint |
+            Qt.WindowType.WindowStaysOnTopHint |
+            Qt.WindowType.Tool |
+            Qt.WindowType.WindowDoesNotAcceptFocus
+        )
+        self.setAttribute(Qt.WidgetAttribute.WA_TranslucentBackground)
+        self.setAttribute(Qt.WidgetAttribute.WA_DeleteOnClose)
+        
+        # Make draggable
+        self._dragging = False
+        self._drag_offset = QPoint()
+    
+    def _setup_ui(self):
+        """Setup the activity bar UI."""
+        self.main_layout = QVBoxLayout(self)
+        self.main_layout.setContentsMargins(4, 4, 4, 4)
+        self.main_layout.setSpacing(2)
+        
+        # Main container
+        self.container = QFrame()
+        self.container.setObjectName("activityBarContainer")
+        self.main_layout.addWidget(self.container)
+        
+        # Container layout based on config
+        self._update_container_layout()
+        
+        # Add pinned plugins
+        self._refresh_pinned_plugins()
+        
+        # Drawer button (always last)
+        self.drawer_btn = self._create_drawer_button()
+        self._add_to_container(self.drawer_btn)
+        
+        # Setup drawer panel
+        self._setup_drawer()
+    
+    def _update_container_layout(self):
+        """Update container layout based on config."""
+        # Clear existing layout
+        old_layout = self.container.layout()
+        if old_layout:
+            while old_layout.count():
+                item = old_layout.takeAt(0)
+                if item.widget():
+                    item.widget().setParent(None)
+            import sip
+            sip.delete(old_layout)
+        
+        # Create new layout
+        if self.config.layout == ActivityBarLayout.HORIZONTAL:
+            layout = QHBoxLayout(self.container)
+        elif self.config.layout == ActivityBarLayout.VERTICAL:
+            layout = QVBoxLayout(self.container)
+        else:  # GRID
+            layout = QGridLayout(self.container)
+        
+        layout.setContentsMargins(6, 6, 6, 6)
+        layout.setSpacing(4)
+        self.container.setLayout(layout)
+        
+        # Update container style
+        self._update_style()
+    
+    def _update_style(self):
+        """Update container styling."""
+        opacity = int(self.config.opacity * 255)
+        border_radius = 12 if self.config.layout == ActivityBarLayout.GRID else 20
+        
+        self.container.setStyleSheet(f"""
+            QFrame#activityBarContainer {{
+                background-color: rgba(35, 40, 55, {opacity});
+                border: 1px solid rgba(100, 110, 130, 100);
+                border-radius: {border_radius}px;
+            }}
+        """)
+    
+    def _create_drawer_button(self) -> QPushButton:
+        """Create the app drawer button."""
+        btn = QPushButton("⋮⋮⋮")  # Drawer icon
+        btn.setFixedSize(self.config.size, self.config.size)
+        btn.setStyleSheet(f"""
+            QPushButton {{
+                background-color: rgba(255, 140, 66, 200);
+                color: white;
+                border: none;
+                border-radius: {self.config.size // 4}px;
+                font-size: 16px;
+                font-weight: bold;
+            }}
+            QPushButton:hover {{
+                background-color: rgba(255, 140, 66, 255);
+            }}
+        """)
+        btn.setToolTip("Plugin Drawer")
+        btn.clicked.connect(self._toggle_drawer)
+        return btn
+    
+    def _create_plugin_button(self, plugin_id: str, plugin_class) -> QPushButton:
+        """Create a plugin button for the bar."""
+        btn = QPushButton()
+        btn.setFixedSize(self.config.size, self.config.size)
+        
+        # Get icon
+        icon_name = getattr(plugin_class, 'icon', 'box')
+        try:
+            from core.icon_manager import get_icon_manager
+            icon_mgr = get_icon_manager()
+            pixmap = icon_mgr.get_pixmap(icon_name, size=self.config.size - 12)
+            btn.setIcon(QIcon(pixmap))
+            btn.setIconSize(QSize(self.config.size - 12, self.config.size - 12))
+        except:
+            # Fallback to emoji
+            btn.setText("📦")
+        
+        # Style
+        btn.setStyleSheet(f"""
+            QPushButton {{
+                background-color: rgba(60, 65, 80, 180);
+                border: none;
+                border-radius: {self.config.size // 4}px;
+            }}
+            QPushButton:hover {{
+                background-color: rgba(80, 85, 100, 220);
+            }}
+        """)
+        
+        # Tooltip
+        btn.setToolTip(plugin_class.name)
+        
+        # Click handler
+        btn.clicked.connect(lambda: self._on_plugin_clicked(plugin_id))
+        
+        return btn
+    
+    def _add_to_container(self, widget: QWidget):
+        """Add widget to container based on layout."""
+        layout = self.container.layout()
+        
+        if isinstance(layout, QGridLayout):
+            # For grid, calculate position
+            count = layout.count()
+            col = count % self.config.grid_columns
+            row = count // self.config.grid_columns
+            layout.addWidget(widget, row, col)
+        else:
+            layout.addWidget(widget)
+    
+    def _refresh_pinned_plugins(self):
+        """Refresh pinned plugins in the bar."""
+        # Clear existing pinned buttons (except drawer)
+        for btn in self.pinned_buttons.values():
+            btn.deleteLater()
+        self.pinned_buttons.clear()
+        
+        if not self.plugin_manager:
+            return
+        
+        # Get all enabled plugins
+        all_plugins = self.plugin_manager.get_all_discovered_plugins()
+        
+        # Add pinned plugins
+        for plugin_id in self.config.pinned_plugins:
+            if plugin_id in all_plugins:
+                plugin_class = all_plugins[plugin_id]
+                btn = self._create_plugin_button(plugin_id, plugin_class)
+                self.pinned_buttons[plugin_id] = btn
+                self._add_to_container(btn)
+    
+    def _setup_drawer(self):
+        """Setup the plugin drawer panel."""
+        self.drawer = QFrame(self.parent())
+        self.drawer.setWindowFlags(
+            Qt.WindowType.FramelessWindowHint |
+            Qt.WindowType.WindowStaysOnTopHint |
+            Qt.WindowType.Tool
+        )
+        self.drawer.setAttribute(Qt.WidgetAttribute.WA_TranslucentBackground)
+        self.drawer.hide()
+        
+        # Drawer layout
+        drawer_layout = QVBoxLayout(self.drawer)
+        drawer_layout.setContentsMargins(12, 12, 12, 12)
+        drawer_layout.setSpacing(8)
+        
+        # Drawer header
+        header = QLabel("Plugin Drawer")
+        header.setStyleSheet("""
+            color: white;
+            font-size: 16px;
+            font-weight: bold;
+        """)
+        drawer_layout.addWidget(header)
+        
+        # Scroll area for plugins
+        scroll = QScrollArea()
+        scroll.setWidgetResizable(True)
+        scroll.setFrameShape(QFrame.Shape.NoFrame)
+        scroll.setStyleSheet("background: transparent;")
+        
+        self.drawer_content = QWidget()
+        self.drawer_layout = QGridLayout(self.drawer_content)
+        self.drawer_layout.setSpacing(8)
+        
+        scroll.setWidget(self.drawer_content)
+        drawer_layout.addWidget(scroll)
+        
+        # Refresh drawer content
+        self._refresh_drawer()
+    
+    def _refresh_drawer(self):
+        """Refresh plugin drawer content."""
+        # Clear existing
+        while self.drawer_layout.count():
+            item = self.drawer_layout.takeAt(0)
+            if item.widget():
+                item.widget().deleteLater()
+        
+        if not self.plugin_manager:
+            return
+        
+        all_plugins = self.plugin_manager.get_all_discovered_plugins()
+        
+        col = 0
+        row = 0
+        for plugin_id, plugin_class in all_plugins.items():
+            # Skip already pinned
+            if plugin_id in self.config.pinned_plugins:
+                continue
+            
+            # Create plugin item
+            item = self._create_drawer_item(plugin_id, plugin_class)
+            self.drawer_layout.addWidget(item, row, col)
+            
+            col += 1
+            if col >= 4:  # 4 columns
+                col = 0
+                row += 1
+    
+    def _create_drawer_item(self, plugin_id: str, plugin_class) -> QFrame:
+        """Create a drawer item for a plugin."""
+        frame = QFrame()
+        frame.setFixedSize(80, 80)
+        frame.setStyleSheet("""
+            QFrame {
+                background-color: rgba(50, 55, 70, 200);
+                border-radius: 8px;
+            }
+            QFrame:hover {
+                background-color: rgba(70, 75, 90, 220);
+            }
+        """)
+        
+        layout = QVBoxLayout(frame)
+        layout.setContentsMargins(4, 4, 4, 4)
+        layout.setSpacing(2)
+        
+        # Icon
+        icon_label = QLabel("📦")
+        icon_label.setStyleSheet("font-size: 24px;")
+        icon_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
+        layout.addWidget(icon_label)
+        
+        # Name
+        name_label = QLabel(plugin_class.name[:8])
+        name_label.setStyleSheet("color: white; font-size: 9px;")
+        name_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
+        layout.addWidget(name_label)
+        
+        # Click to open
+        frame.mousePressEvent = lambda e, pid=plugin_id: self._on_drawer_item_clicked(pid)
+        
+        return frame
+    
+    def _toggle_drawer(self):
+        """Toggle the plugin drawer."""
+        self.drawer_open = not self.drawer_open
+        
+        if self.drawer_open:
+            # Position drawer near activity bar
+            pos = self.pos()
+            if self.config.layout == ActivityBarLayout.HORIZONTAL:
+                self.drawer.move(pos.x(), pos.y() - 300)
+            else:
+                self.drawer.move(pos.x() + self.width(), pos.y())
+            
+            self.drawer.resize(360, 300)
+            self.drawer.show()
+            self.drawer_toggled.emit(True)
+        else:
+            self.drawer.hide()
+            self.drawer_toggled.emit(False)
+    
+    def _on_plugin_clicked(self, plugin_id: str):
+        """Handle plugin button click."""
+        print(f"[ActivityBar] Plugin clicked: {plugin_id}")
+        self.widget_requested.emit(plugin_id)
+    
+    def _on_drawer_item_clicked(self, plugin_id: str):
+        """Handle drawer item click."""
+        print(f"[ActivityBar] Drawer item clicked: {plugin_id}")
+        self.widget_requested.emit(plugin_id)
+        self._toggle_drawer()  # Close drawer
+    
+    def _auto_hide(self):
+        """Auto-hide the activity bar."""
+        if self.config.auto_hide and not self.config.always_visible:
+            # Check if mouse is over bar or drawer
+            if not self.underMouse() and not self.drawer.underMouse():
+                self.hide()
+    
+    def enterEvent(self, event):
+        """Mouse entered activity bar."""
+        if self.config.auto_hide:
+            self.hide_timer.stop()
+        super().enterEvent(event)
+    
+    def leaveEvent(self, event):
+        """Mouse left activity bar."""
+        if self.config.auto_hide and not self.drawer_open:
+            self.hide_timer.start()
+        super().leaveEvent(event)
+    
+    def mousePressEvent(self, event: QMouseEvent):
+        """Start dragging."""
+        if event.button() == Qt.MouseButton.LeftButton:
+            self._dragging = True
+            self._drag_offset = event.globalPosition().toPoint() - self.frameGeometry().topLeft()
+            event.accept()
+    
+    def mouseMoveEvent(self, event: QMouseEvent):
+        """Drag activity bar."""
+        if self._dragging:
+            new_pos = event.globalPosition().toPoint() - self._drag_offset
+            self.move(new_pos)
+    
+    def mouseReleaseEvent(self, event: QMouseEvent):
+        """Stop dragging."""
+        if event.button() == Qt.MouseButton.LeftButton:
+            self._dragging = False
+            self._save_position()
+    
+    def _apply_config(self):
+        """Apply configuration."""
+        self.setWindowOpacity(self.config.opacity)
+        self._update_style()
+        
+        # Resize based on layout and size
+        if self.config.layout == ActivityBarLayout.HORIZONTAL:
+            self.resize(400, self.config.size + 20)
+        elif self.config.layout == ActivityBarLayout.VERTICAL:
+            self.resize(self.config.size + 20, 400)
+        else:  # GRID
+            self.resize(
+                self.config.grid_columns * (self.config.size + 8) + 20,
+                self.config.grid_rows * (self.config.size + 8) + 20
+            )
+    
+    def _load_config(self) -> ActivityBarConfig:
+        """Load activity bar configuration."""
+        config_path = Path("config/activity_bar.json")
+        if config_path.exists():
+            try:
+                data = json.loads(config_path.read_text())
+                return ActivityBarConfig(**data)
+            except:
+                pass
+        return ActivityBarConfig()
+    
+    def _save_config(self):
+        """Save activity bar configuration."""
+        config_path = Path("config/activity_bar.json")
+        config_path.parent.mkdir(parents=True, exist_ok=True)
+        config_path.write_text(json.dumps(asdict(self.config), indent=2))
+    
+    def _save_position(self):
+        """Save bar position."""
+        # TODO: Save position to config
+        pass
+    
+    def show_settings_dialog(self):
+        """Show activity bar settings dialog."""
+        dialog = ActivityBarSettingsDialog(self.config, self)
+        if dialog.exec():
+            self.config = dialog.get_config()
+            self._apply_config()
+            self._save_config()
+            self._refresh_pinned_plugins()
+
+
+class ActivityBarSettingsDialog(QDialog):
+    """Settings dialog for activity bar."""
+    
+    def __init__(self, config: ActivityBarConfig, parent=None):
+        super().__init__(parent)
+        
+        self.config = config
+        self.setWindowTitle("Activity Bar Settings")
+        self.setMinimumSize(400, 500)
+        
+        self._setup_ui()
+    
+    def _setup_ui(self):
+        """Setup settings UI."""
+        from PyQt6.QtWidgets import QVBoxLayout, QFormLayout, QDialogButtonBox
+        
+        layout = QVBoxLayout(self)
+        
+        # Form
+        form = QFormLayout()
+        
+        # Enabled
+        self.enabled_cb = QCheckBox("Enable Activity Bar")
+        self.enabled_cb.setChecked(self.config.enabled)
+        form.addRow(self.enabled_cb)
+        
+        # Layout
+        self.layout_combo = QComboBox()
+        self.layout_combo.addItems(["Horizontal", "Vertical", "Grid"])
+        self.layout_combo.setCurrentText(self.config.layout.value.title())
+        form.addRow("Layout:", self.layout_combo)
+        
+        # Size
+        self.size_spin = QSpinBox()
+        self.size_spin.setRange(32, 96)
+        self.size_spin.setValue(self.config.size)
+        form.addRow("Icon Size:", self.size_spin)
+        
+        # Opacity
+        self.opacity_slider = QSlider(Qt.Orientation.Horizontal)
+        self.opacity_slider.setRange(20, 100)
+        self.opacity_slider.setValue(int(self.config.opacity * 100))
+        form.addRow("Opacity:", self.opacity_slider)
+        
+        # Auto-hide
+        self.autohide_cb = QCheckBox("Auto-hide when not in use")
+        self.autohide_cb.setChecked(self.config.auto_hide)
+        form.addRow(self.autohide_cb)
+        
+        # Show labels
+        self.labels_cb = QCheckBox("Show plugin labels")
+        self.labels_cb.setChecked(self.config.show_labels)
+        form.addRow(self.labels_cb)
+        
+        # Grid config
+        self.grid_cols = QSpinBox()
+        self.grid_cols.setRange(2, 8)
+        self.grid_cols.setValue(self.config.grid_columns)
+        form.addRow("Grid Columns:", self.grid_cols)
+        
+        layout.addLayout(form)
+        
+        # Buttons
+        buttons = QDialogButtonBox(
+            QDialogButtonBox.StandardButton.Ok | QDialogButtonBox.StandardButton.Cancel
+        )
+        buttons.accepted.connect(self.accept)
+        buttons.rejected.connect(self.reject)
+        layout.addWidget(buttons)
+    
+    def get_config(self) -> ActivityBarConfig:
+        """Get updated configuration."""
+        layout_map = {
+            "Horizontal": ActivityBarLayout.HORIZONTAL,
+            "Vertical": ActivityBarLayout.VERTICAL,
+            "Grid": ActivityBarLayout.GRID
+        }
+        
+        return ActivityBarConfig(
+            enabled=self.enabled_cb.isChecked(),
+            layout=layout_map.get(self.layout_combo.currentText(), ActivityBarLayout.HORIZONTAL),
+            size=self.size_spin.value(),
+            opacity=self.opacity_slider.value() / 100,
+            auto_hide=self.autohide_cb.isChecked(),
+            show_labels=self.labels_cb.isChecked(),
+            grid_columns=self.grid_cols.value(),
+            pinned_plugins=self.config.pinned_plugins
+        )
+
+
+# Global instance
+_activity_bar: Optional[ActivityBar] = None
+
+
+def get_activity_bar(plugin_manager=None) -> Optional[ActivityBar]:
+    """Get or create global activity bar instance."""
+    global _activity_bar
+    if _activity_bar is None and plugin_manager:
+        _activity_bar = ActivityBar(plugin_manager)
+    return _activity_bar
diff --git a/core/main.py b/core/main.py
index ba51e19..5ad56a6 100644
--- a/core/main.py
+++ b/core/main.py
@@ -122,6 +122,17 @@ class EUUtilityApp:
         self.floating_icon.clicked.connect(self._toggle_overlay)
         self.floating_icon.show()
         
+        # Create Activity Bar (in-game overlay)
+        print("Creating Activity Bar...")
+        from core.activity_bar import get_activity_bar
+        self.activity_bar = get_activity_bar(self.plugin_manager)
+        if self.activity_bar and self.activity_bar.config.enabled:
+            print("[Core] Activity Bar enabled")
+            # Connect signals
+            self.activity_bar.widget_requested.connect(self._on_activity_bar_widget)
+        else:
+            print("[Core] Activity Bar disabled")
+        
         # Connect hotkey signals
         self.hotkey_handler.toggle_signal.connect(self._on_toggle_signal)
         
@@ -301,6 +312,35 @@ class EUUtilityApp:
         """Handle toggle signal in main thread."""
         self._toggle_overlay()
     
+    def _on_activity_bar_widget(self, plugin_id: str):
+        """Handle activity bar widget request."""
+        print(f"[Main] Activity bar requested plugin: {plugin_id}")
+        
+        # Get plugin class
+        all_plugins = self.plugin_manager.get_all_discovered_plugins()
+        if plugin_id not in all_plugins:
+            print(f"[Main] Plugin not found: {plugin_id}")
+            return
+        
+        plugin_class = all_plugins[plugin_id]
+        
+        # Check if plugin has a mini widget
+        if hasattr(plugin_class, 'get_mini_widget'):
+            try:
+                # Create mini widget
+                widget = plugin_class.get_mini_widget()
+                if widget:
+                    widget.show()
+                    print(f"[Main] Created mini widget for {plugin_class.name}")
+            except Exception as e:
+                print(f"[Main] Error creating mini widget: {e}")
+        else:
+            # No mini widget, try to show main overlay
+            self._toggle_overlay()
+            # Switch to this plugin
+            if self.overlay:
+                self.overlay.show_plugin(plugin_id)
+    
     def _toggle_overlay(self):
         """Toggle overlay visibility."""
         if self.overlay: