Hi folk,
I try to make my first GTK4/Adwaita app, but without success.
When I preview my .ui xml file on Cambalache, that look nice, but when I run my app that look crap 
Based on adwaita demo
<?xml version='1.0' encoding='UTF-8'?>
<!-- Created with Cambalache 0.94.0 -->
<interface>
<!-- interface-name main_window.ui -->
<requires lib="gtk" version="4.12"/>
<requires lib="libadwaita" version="1.4"/>
<requires lib="gio" version="2.0"/>
<!-- Menu model -->
<menu id="primary_menu">
<section>
<item>
<attribute name="action">app.inspector</attribute>
<attribute name="label" translatable="yes">_Inspector</attribute>
</item>
</section>
<section>
<item>
<attribute name="action">app.preferences</attribute>
<attribute name="label" translatable="yes">_Preferences</attribute>
</item>
<item>
<attribute name="action">app.about</attribute>
<attribute name="label" translatable="yes">_About Adwaita Demo</attribute>
</item>
</section>
</menu>
<!-- Main window template -->
<template class="MainWindow" parent="AdwApplicationWindow">
<!-- Window content -->
<property name="content">
<object class="AdwToolbarView">
<!-- Main content area -->
<property name="content">
<object class="AdwOverlaySplitView" id="split_view">
<!-- Content view -->
<property name="content">
<object class="AdwStatusPage">
<property name="title" translatable="yes">Content</property>
</object>
</property>
<!-- Navigation menu -->
<property name="show-sidebar" bind-source="show_sidebar_button" bind-property="active" bind-flags="sync-create|bidirectional"/>
<property name="sidebar">
<object class="AdwStatusPage">
<property name="child">
<object class="GtkBox">
<property name="spacing">18</property>
<child type="start">
<object class="GtkDropDown" id="company_dropdown">
<property name="enable-search">true</property>
<property name="hexpand">True</property>
<property name="tooltip-text">Select a company</property>
</object>
</child>
<child type="start">
<object class="GtkButton" id="add_company_button">
<property name="icon-name">list-add-symbolic</property>
<property name="tooltip-text">Add a new company</property>
</object>
</child>
</object>
</property>
<property name="title">Sidebar</property>
<property name="valign">start</property>
</object>
</property>
</object>
</property>
<!-- Header bar -->
<property name="top-bar-style">raised</property>
<child type="top">
<object class="AdwHeaderBar">
<child type="start">
<object class="GtkToggleButton" id="show_sidebar_button">
<property name="active">True</property>
<property name="icon-name">view-sidebar-start-symbolic</property>
<property name="tooltip-text" translatable="yes">Toggle Sidebar</property>
<property name="visible"/>
</object>
</child>
<child type="end">
<object class="GtkToggleButton">
<property name="active" bind-source="show_sidebar_button" bind-property="active" bind-flags="sync-create|bidirectional"/>
<property name="icon-name">view-sidebar-end-symbolic</property>
<property name="tooltip-text" translatable="yes">Toggle Sidebar</property>
<property name="visible"/>
</object>
</child>
<child type="end">
<object class="GtkMenuButton" id="menu_button">
<property name="icon-name">open-menu-symbolic</property>
<property name="menu-model">primary_menu</property>
<property name="primary">True</property>
<property name="tooltip-text" translatable="yes">Main Menu</property>
</object>
</child>
</object>
</child>
</object>
</property>
<property name="default-height">600</property>
<property name="default-width">1800</property>
<property name="title" translatable="yes">_AppTitle</property>
<child>
<object class="AdwBreakpoint">
<!-- Custom object fragments -->
<condition>max-width: 800sp</condition>
<setter object="split_view" property="collapsed">True</setter>
</object>
</child>
</template>
</interface>
And I loading it on C
G_DEFINE_TYPE(MainWindow, main_window, ADW_TYPE_APPLICATION_WINDOW)
...
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
gtk_widget_class_set_template_from_resource(widget_class,
"/test/src/views/main_window.ui");
gtk_widget_class_bind_template_child(widget_class, MainWindow, show_sidebar_button);
gtk_widget_class_bind_template_child(widget_class, MainWindow, menu_button);
gtk_widget_class_bind_template_child(widget_class, MainWindow, company_dropdown);
gtk_widget_class_bind_template_child(widget_class, MainWindow, add_company_button);
gtk_widget_class_bind_template_child(widget_class, MainWindow, split_view);
...
C compiler for the host machine: cc (gcc 14.2.1 "cc (GCC) 14.2.1 20240910")
C linker for the host machine: cc ld.bfd 2.43.0
Host machine cpu family: x86_64
Host machine cpu: x86_64
Found pkg-config: YES (/sbin/pkg-config) 2.3.0
Run-time dependency gtk4 found: YES 4.16.7
Run-time dependency libadwaita-1 found: YES 1.6.2
Run-time dependency libxml-2.0 found: YES 2.13.5
Build-time dependency gio-2.0 found: YES 2.82.2