diff --git a/README.md b/README.md
index c5d57ea..ed02d84 100644
--- a/README.md
+++ b/README.md
@@ -106,7 +106,7 @@ Layer Shell and X11 hints are requests, not universal guarantees. Same-layer win
 | `--overlay-opacity=0.90` | `0.90` | Dark bubble opacity from `0` to `1`. |
 | `--overlay-font-size=28` | `28` | Font size in logical pixels. |
 | `--overlay-bottom-margin=100` | `100` | Bottom margin in logical pixels. |
-| `--overlay-max-width=1200` | `1200` | Width cap; the overlay also limits itself to 80% of the selected monitor. |
+| `--overlay-max-width=1200` | `1200` | Fixed caption-bubble width; it is capped at 80% of the selected monitor. |
 | `--overlay-monitor=auto` | `auto` | `auto`, a zero-based monitor index, or a connector name such as `DP-1`. |
 | `--overlay-final-timeout=4s` | `4s` | Time before the final row disappears. `0s` keeps it until replaced or hidden. |
 | `--overlay-click-through=true` | `true` | Use an empty input region where the display backend supports it. |
diff --git a/src/config/config.go b/src/config/config.go
index 143fef8..c41840b 100644
--- a/src/config/config.go
+++ b/src/config/config.go
@@ -86,7 +86,7 @@ func ParseDesktop() DesktopSettings {
 	flags.Float64Var(&desktop.Overlay.Opacity, "overlay-opacity", 0.90, "caption background opacity from 0 to 1")
 	flags.IntVar(&desktop.Overlay.FontSize, "overlay-font-size", 28, "caption font size in logical pixels")
 	flags.IntVar(&desktop.Overlay.BottomMargin, "overlay-bottom-margin", 100, "distance from the monitor bottom in logical pixels")
-	flags.IntVar(&desktop.Overlay.MaxWidth, "overlay-max-width", 1200, "maximum caption width in logical pixels")
+	flags.IntVar(&desktop.Overlay.MaxWidth, "overlay-max-width", 1200, "fixed caption width in logical pixels before the monitor safety cap")
 	flags.StringVar(&desktop.Overlay.Monitor, "overlay-monitor", "auto", "monitor selection: auto, numeric index, or connector name")
 	flags.DurationVar(&desktop.Overlay.FinalTimeout, "overlay-final-timeout", 4*time.Second, "how long a final caption remains; zero waits for replacement")
 	flags.BoolVar(&desktop.Overlay.ClickThrough, "overlay-click-through", true, "pass pointer input through the caption window")
diff --git a/src/output/overlay/overlay_gtk.go b/src/output/overlay/overlay_gtk.go
index ee4d6c4..fd0d05a 100644
--- a/src/output/overlay/overlay_gtk.go
+++ b/src/output/overlay/overlay_gtk.go
@@ -344,19 +344,20 @@ static CaptioneerOverlay *captioneer_overlay_new(
 	overlay->bubble = box;
 	gtk_widget_add_css_class(box, "captioneer-bubble");
 	gtk_widget_set_halign(box, GTK_ALIGN_CENTER);
+	gtk_widget_set_size_request(box, effective_width, -1);
 
 	overlay->final_label = gtk_label_new("");
 	overlay->preview_label = gtk_label_new("");
 	GtkWidget *labels[] = {overlay->final_label, overlay->preview_label};
 	for (guint i = 0; i < G_N_ELEMENTS(labels); i++) {
-		gtk_label_set_justify(GTK_LABEL(labels[i]), GTK_JUSTIFY_CENTER);
-		gtk_label_set_xalign(GTK_LABEL(labels[i]), 0.5f);
+		gtk_label_set_justify(GTK_LABEL(labels[i]), GTK_JUSTIFY_LEFT);
+		gtk_label_set_xalign(GTK_LABEL(labels[i]), 0.0f);
 		gtk_label_set_wrap(GTK_LABEL(labels[i]), TRUE);
 		gtk_label_set_wrap_mode(GTK_LABEL(labels[i]), PANGO_WRAP_WORD_CHAR);
 		gtk_label_set_lines(GTK_LABEL(labels[i]), 2);
 		gtk_label_set_ellipsize(GTK_LABEL(labels[i]), PANGO_ELLIPSIZE_END);
 		gtk_label_set_max_width_chars(GTK_LABEL(labels[i]), max_chars);
-		gtk_widget_set_halign(labels[i], GTK_ALIGN_CENTER);
+		gtk_widget_set_halign(labels[i], GTK_ALIGN_FILL);
 		gtk_box_append(GTK_BOX(box), labels[i]);
 		gtk_widget_set_visible(labels[i], FALSE);
 	}