Update README.md

Remove the day mode

Author: woshimajintao

annotation_tool/style/README.md

@@ -1,24 +1,19 @@
+
 # 🎨 Application Stylesheets (QSS)
 
-This directory contains the **Qt Style Sheets (.qss)** that define the visual appearance of the application. The tool supports dynamic theme switching between **Dark Mode** (default) and **Light Mode**.
+This directory contains the **Qt Style Sheets (.qss)** that define the visual appearance of the application. The tool currently ships with a single default theme: **Dark Mode**.
 
 ## 📂 Files
 
-### 1. `style.qss` (Night Mode)
+### 1. `style.qss` (Dark Mode)
 * **Type:** Default Theme.
 * **Palette:**
     * **Backgrounds:** Deep Grays (`#2E2E2E`, `#3C3C3C`).
     * **Text:** Off-White (`#F0F0F0`).
-    * **Accents:** Bright Blue (`#00BFFF`) and Darker Greys for borders.
+    * **Accents:** Bright Blue (`#00BFFF`) and darker greys for borders.
 * **Usage:** Optimized for long annotation sessions to reduce eye strain in low-light environments.
 
-### 2. `style_day.qss` (Day Mode)
-* **Type:** Alternative Theme.
-* **Palette:**
-    * **Backgrounds:** Light Grays (`#E0E0E0`, `#F0F0F0`).
-    * **Text:** Dark Charcoal (`#1E1E1E`) for high contrast.
-    * **Accents:** Teal/Cyan (`#00AACC`) and Blue (`#0088CC`).
-* **Usage:** Optimized for bright environments, presentations, or projectors.
+> Note: `style_day.qss` (Light/Day Mode) has been removed. The application no longer supports theme switching out of the box.
 
 ---
 
@@ -27,16 +22,16 @@ This directory contains the **Qt Style Sheets (.qss)** that define the visual ap
 These files use standard CSS-like syntax adapted for Qt Widgets (`QWidget`, `QPushButton`, `QTreeWidget`, etc.).
 
 ### Key Styling Features
-1.  **Collapsible Group Boxes**:
-    * We utilize a CSS trick to animate the `QGroupBox` folding mechanism.
-    * The selector `QGroupBox::checkable:checked > QWidget` controls the `max-height` property to hide or show content without requiring complex Python animation code.
+1. **Collapsible Group Boxes**
+   * We utilize a CSS trick to animate the `QGroupBox` folding mechanism.
+   * The selector `QGroupBox::checkable:checked > QWidget` controls the `max-height` property to hide or show content without requiring complex Python animation code.
 
-2.  **Custom Indicators**:
-    * `QRadioButton` and `QCheckBox` indicators are customized to match the theme colors.
-    * `QTreeWidget` headers are styled to blend seamlessly with the panel backgrounds.
+2. **Custom Indicators**
+   * `QRadioButton` and `QCheckBox` indicators are customized to match the theme colors.
+   * `QTreeWidget` headers are styled to blend seamlessly with the panel backgrounds.
 
-3.  **Interactive States**:
-    * All buttons define specific styles for `:hover`, `:pressed`, and `:disabled` states to provide immediate visual feedback to the user.
+3. **Interactive States**
+   * Buttons define specific styles for `:hover`, `:pressed`, and `:disabled` states to provide immediate visual feedback to the user.
 
 ## 🔄 Loading Logic
-The themes are loaded dynamically in `viewer.py` (or `main_window.py`). When the user toggles the mode, the application reads the text content of the target `.qss` file and applies it via `self.setStyleSheet(...)`.
+The stylesheet is loaded during application startup (typically in `main.py` or `viewer.py`). The application reads the `.qss` file content and applies it via `setStyleSheet(...)`.