Move flags/timer out of the header bar into a status bar above the grid

Header bar now holds only Difficulty + Leaderboard. A status bar above the
board shows the flag counter (left), the New Game button (center) and the
timer (right) as LCD-style panels styled with theme-aware CSS.

src/window.cpp

@@ -21,14 +21,27 @@ MainWindow::MainWindow() {
     setup_header_bar();
     setup_board();
 
-    // Popovers: some GTK themes (and newer GTK versions) leave the popover
-    // surface transparent unless the content opts in. Guarantee an opaque,
-    // theme-aware background.
-    auto popover_css = Gtk::CssProvider::create();
-    popover_css->load_from_data(
-        "popover.background > contents { background-color: @theme_bg_color; }");
+    // App-wide CSS: opaque popovers (some themes/GTK versions leave them
+    // transparent), plus the status bar above the grid (flags/timer panels).
+    auto app_css = Gtk::CssProvider::create();
+    app_css->load_from_data(R"CSS(
+popover.background > contents { background-color: @theme_bg_color; }
+
+.status-bar {
+    padding: 8px 12px;
+    border-bottom: 1px solid alpha(@theme_fg_color, 0.12);
+}
+.status-panel {
+    background-color: alpha(@theme_fg_color, 0.85);
+    border-radius: 8px;
+    padding: 4px 14px;
+    color: @theme_bg_color;
+    font-family: monospace;
+    font-weight: bold;
+}
+)CSS");
     Gtk::StyleContext::add_provider_for_display(
-        get_display(), popover_css, GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+        get_display(), app_css, GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
 
     // Keyboard shortcuts
     auto key_controller = Gtk::EventControllerKey::create();
@@ -81,13 +94,6 @@ MainWindow::~MainWindow() {
 void MainWindow::setup_header_bar() {
     set_titlebar(header_bar_);
 
-    // New Game Button
-    btn_new_game_.set_label("New Game");
-    btn_new_game_.signal_clicked().connect([this]() {
-        start_new_game(current_difficulty_);
-    });
-    header_bar_.pack_start(btn_new_game_);
-
     // Difficulty Menu
     btn_difficulty_.set_label(Minefield::DifficultyEasy.name);
 
@@ -138,17 +144,6 @@ void MainWindow::setup_header_bar() {
     menu_leaderboard_.add_css_class("menu");
     menu_leaderboard_.signal_show().connect(sigc::mem_fun(*this, &MainWindow::refresh_leaderboard));
     header_bar_.pack_start(btn_leaderboard_);
-
-    // Status Labels
-    lbl_flags_.set_margin_end(10);
-    lbl_time_.set_margin_end(10);
-    
-    // Monospaced and bold so the numbers don't jitter
-    lbl_flags_.set_markup("<b><tt>Flags: 0</tt></b>");
-    lbl_time_.set_markup("<b><tt>Time: 00:00</tt></b>");
-
-    header_bar_.pack_end(lbl_time_);
-    header_bar_.pack_end(lbl_flags_);
 }
 
 void MainWindow::refresh_leaderboard() {
@@ -172,10 +167,27 @@ void MainWindow::refresh_leaderboard() {
 }
 
 void MainWindow::setup_board() {
-    // Minimum size so the largest board (30x20, Master) fits at the 16px
-    // cell floor even when tiled very small.
-    board_widget_.set_size_request(520, 360);
-    set_child(board_widget_);
+    vbox_.set_orientation(Gtk::Orientation::VERTICAL);
+
+    // Status bar above the grid: flags (left), new game (center), timer (right)
+    btn_new_game_.set_label("New Game");
+    btn_new_game_.signal_clicked().connect([this]() {
+        start_new_game(current_difficulty_);
+    });
+    lbl_flags_.set_text("Flags: 0");
+    lbl_time_.set_text("Time: 00:00");
+    lbl_flags_.add_css_class("status-panel");
+    lbl_time_.add_css_class("status-panel");
+
+    status_bar_.add_css_class("status-bar");
+    status_bar_.set_start_widget(lbl_flags_);
+    status_bar_.set_center_widget(btn_new_game_);
+    status_bar_.set_end_widget(lbl_time_);
+
+    vbox_.append(status_bar_);
+    vbox_.append(board_widget_);
+    set_child(vbox_);
+
     board_widget_.signal_state_changed.connect(sigc::mem_fun(*this, &MainWindow::on_game_state_changed));
 }
 
@@ -193,6 +205,11 @@ void MainWindow::start_new_game(const GameDifficulty& difficulty) {
     
     minefield_ = std::make_shared<Minefield>(difficulty.cols, difficulty.rows, difficulty.mines);
     board_widget_.set_minefield(minefield_);
+
+    // Minimum size: let the window shrink down to what the current board
+    // needs at the 16px cell floor (30x20 Master requires 520x360, but a
+    // 9x9 Beginner board fits in ~184px).
+    board_widget_.set_size_request(difficulty.cols * 16 + 40, difficulty.rows * 16 + 40);
     
     // Size the window to fit the board at a comfortable cell size.
     // Ignored once the user has resized the window (or under a tiling WM).
@@ -211,7 +228,7 @@ void MainWindow::on_game_state_changed() {
     if (!minefield_) return;
 
     // Update Flags
-    lbl_flags_.set_markup("<b><tt>Flags: " + std::to_string(minefield_->remaining_flags()) + "</tt></b>");
+    lbl_flags_.set_text("Flags: " + std::to_string(minefield_->remaining_flags()));
 
     // Check Game Over
     GameState state = minefield_->state();
@@ -236,7 +253,7 @@ bool MainWindow::on_timer_tick() {
     auto elapsed = minefield_->get_elapsed_time();
     auto secs = std::chrono::duration_cast<std::chrono::seconds>(elapsed).count();
     
-    lbl_time_.set_markup("<b><tt>Time: " + format_time(secs) + "</tt></b>");
+    lbl_time_.set_text("Time: " + format_time(secs));
     
     return true; // Keep calling
 }

src/window.hpp

@@ -27,7 +27,6 @@ private:
 
     // Widgets
     Gtk::HeaderBar header_bar_;
-    Gtk::Button btn_new_game_;
     Gtk::MenuButton btn_difficulty_;
     Gtk::Popover menu_difficulty_;
     Gtk::Box box_difficulty_; // Content for popover
@@ -37,6 +36,9 @@ private:
     Gtk::Popover menu_leaderboard_;
     Gtk::Box box_leaderboard_; // Content for popover
 
+    Gtk::Box vbox_;                    // Main vertical container
+    Gtk::CenterBox status_bar_;        // Flags | New Game | Time
+    Gtk::Button btn_new_game_;
     Gtk::Label lbl_time_;
     Gtk::Label lbl_flags_;