Update README.md

Adjustment of subheading spacing

README.md

@@ -53,13 +53,13 @@ Tester1/
 │   └── ...
 ```
 
-## `Gaze_object_output/`
+### `Gaze_object_output/`
 This directory contains **gaze–object annotation files** for each scene.
 **File format**
 - `<scene_id>`: scene index (starting from 0)
 - Each row corresponds to one time step / frame
 ---
-#### Gaze Target Information
+##### Gaze Target Information
 - `Stare_obj`: ID of the object being gazed at  
   - `0` indicates background or no valid gaze target
 - `Stare_area`: coarse gaze region label on the screen
@@ -73,7 +73,7 @@ The screen resolution is **5740 × 1010**, and gaze regions are defined as:
 | `MB` | Rear-view mirror | `[2890, 210] – [3540, 400]` |
 
 ---
-#### Vehicle Screen Positions
+##### Vehicle Screen Positions
 - `Car{i}_screen_X`, `Car{i}_screen_Y`: 2D screen-space coordinates of risk-relevant vehicles
 - Coordinates are aligned with the same frame as gaze annotations
 - Missing vehicles are filled with `0`
@@ -87,14 +87,14 @@ These files jointly describe **where the driver is looking** and **where potenti
 
 
 
-## `Tester1_feature_csv/`
+### `Tester1_feature_csv/`
 This directory contains **per-frame driving state and scene feature files** for each scene.
 **File format**
 - `<scene_id>`: scene index (starting from 0)
 - Each row corresponds to one time step / frame
 - Rows are time-aligned with gaze annotations and instance segmentation outputs
 ---
-#### Ego Vehicle and Driver State
+##### Ego Vehicle and Driver State
 - `time`: timestamp (Unix time)
 - `steering`: steering wheel angle
 - `accelerator`: accelerator pedal value
@@ -103,11 +103,11 @@ This directory contains **per-frame driving state and scene feature files** for
 - `Handchange_flag`: handover / control change indicator
 - `Collision_flag`: collision indicator (binary)
 ---
-#### Ego Vehicle Position
+##### Ego Vehicle Position
 - `main_car_id`: ID of the ego vehicle
 - `main_car_x`, `main_car_y`: ego vehicle position in world coordinates
 ---
-#### Surrounding Risk Object Features
+##### Surrounding Risk Object Features
 For each risk-relevant object in the scene, features are stored using indexed columns:
 
 - Object indices: `Car1` … `Car9`
@@ -117,7 +117,7 @@ For each risk-relevant object in the scene, features are stored using indexed co
   - Additional kinematic or geometric features
 If a risk object is not present in a frame, its corresponding feature values are filled with `0`.
 ---
-#### Gaze Point Projection
+##### Gaze Point Projection
 - `ScreenPoint2D_x`, `ScreenPoint2D_y`: projected 2D gaze point on the screen, aligned with gaze annotations
 ---
 These files provide **low-level driving signals, ego vehicle states, and scene-level object features**, and are intended to be used jointly with: