set a different default UI style

Makefile

@@ -1,6 +1,11 @@
 # Compiler and flags
 CXX = g++
-CXXFLAGS = -Wall -Wextra -g -ggdb3 -std=c++14 -I./src -isystem./ext/raylib/src -I./ext/tomlc17/src -isystem./ext/raygui/src
+CXXFLAGS = -Wall -Wextra -g -ggdb3 -std=c++14 \
+		   -I./src \
+		   -isystem./ext/tomlc17/src \
+		   -isystem./ext/raylib/src \
+		   -isystem./ext/raygui/src \
+		   -isystem./ext/raygui/styles
 LDFLAGS = -L./ext/raylib/src -lraylib -lm -lpthread -ldl -lrt -lX11
 
 # Directories

src/main.cpp

@@ -9,8 +9,8 @@
 #include <cmath>
 
 // Configuration defaults - edit to change default run mode
-//#define DEFAULT_CONFIG_FILE "configs/test_simple.toml"
-#define DEFAULT_CONFIG_FILE "tests/configs/solar_system.toml"
+//#define DEFAULT_CONFIG_FILE "tests/configs/solar_system.toml"
+#define DEFAULT_CONFIG_FILE "tests/configs/maneuver_sequence.toml"
 
 struct ProgramArgs {
     const char* config_file;
@@ -61,6 +61,7 @@ void run_gui_simulation(SimulationState* sim) {
     // Initialize UI state
     ui_state.body_list_scroll = 0;     // Initial scroll position
     ui_state.body_list_active = root_body_index >= 0 ? root_body_index : -1;  // Sync with selected body
+    gui_init();
 
     bool paused = false;
     double speed_multiplier = 1.0;

src/ui_renderer.cpp

@@ -8,6 +8,11 @@
 // raygui implementation (header-only library)
 #define RAYGUI_IMPLEMENTATION
 #include "raygui.h"
+#include "amber/style_amber.h"
+
+void gui_init() {
+    GuiLoadStyleAmber();
+}
 
 // Render simulation information overlay
 void render_info(SimulationState* sim) {

src/ui_renderer.h

@@ -11,6 +11,8 @@ struct UIState {
     int body_list_active;     // Active item index in body list
 };
 
+void gui_init();
+
 // UI rendering functions
 void render_info(SimulationState* sim);
 void render_body_list_ui(SimulationState* sim, RenderState* render_state, UIState* ui_state);