#include void load_application_css() { const gchar *css_string = ".red_text { color: red; }"; GtkCssProvider *css = gtk_css_provider_new(); gtk_css_provider_load_from_data(css, css_string, -1, NULL); gtk_style_context_add_provider_for_screen(gdk_screen_get_default(), GTK_STYLE_PROVIDER(css), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION); g_object_unref(css); } GtkWidget* create_entry() { GtkWidget *entry = gtk_entry_new(); /* style this entry. */ /* Apply one of our own CSS classes. */ gtk_style_context_add_class(gtk_widget_get_style_context(entry), "red_text"); return entry; } void init() { GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL); GtkWidget *entry = create_entry(); gtk_container_add(GTK_CONTAINER(window), entry); gtk_widget_show_all(window); g_signal_connect(window, "destroy", gtk_main_quit, NULL); } int main(int argc, char **argv) { gtk_init(&argc, &argv); load_application_css(); init(); gtk_main(); return 0; }