# Button Highlighting Update

## ✅ Active Button Highlighting Implemented

Added proper visual feedback to show which frame type filter is currently selected.

## 🎨 Visual Appearance

### **Active Button (Selected)**
- **Background**: Blue (#0080ff) - same as the original tab highlighting
- **Text**: Bold white text
- **Class**: `-active` CSS class applied

### **Inactive Buttons**
- **Background**: Dark gray (#262626)
- **Text**: Gray text (#999999)
- **Hover**: Lighter blue background on mouse over

### **Button Layout**
```
[1. Overview]  [2. CH10-Data(1105)]  [3. UDP(443)]  [4. PTP-Signaling(240)]
    ↑ Active      ↑ Inactive          ↑ Inactive      ↑ Inactive
```

## 🔧 Implementation Details

### **Highlighting Logic**
1. **Initial State**: Overview button starts highlighted (blue background)
2. **Button Click**: Clicked button becomes active, others become inactive
3. **Keyboard Navigation**: Number key selection updates highlighting
4. **Dynamic Updates**: Highlighting preserved when buttons are refreshed

### **Key Methods Added**
- `_update_button_highlighting()` - Updates active/inactive state for all buttons
- Called after button selection, frame type refresh, and initial mount
- Uses CSS `-active` class for consistent styling

### **CSS Classes**
```css
#filter-bar Button.-active {
    background: #0080ff;
    text-style: bold;
}

#filter-bar Button {
    background: transparent;
    color: #999999;
}

#filter-bar Button:hover {
    background: #0080ff;
}
```

## ⌨️ User Experience

### **Visual Feedback**
- **Clear indication** of which filter is currently active
- **Consistent styling** with the rest of the StreamLens interface
- **Immediate feedback** when switching between filters

### **Interaction Flow**
1. **Start**: Overview button highlighted in blue
2. **Press `2`**: CH10-Data button becomes blue, Overview becomes gray
3. **Press `3`**: UDP button becomes blue, CH10-Data becomes gray
4. **etc.**

### **Expected Behavior**
- Active button is clearly highlighted in blue with bold text
- Only one button highlighted at a time
- Highlighting updates immediately on selection
- Consistent with original tab-style highlighting you mentioned

## 🎯 Result

The button bar now provides clear visual feedback showing which frame type filter is currently selected, matching the highlighting style you referenced from the original tab interface.

The interface should now feel complete with proper active button indication!