5 files changed, 74 insertions, 6 deletions
diff --git a/internal/web/render.go b/internal/web/render.go
index ca5bb89..208fc59 100644
--- a/internal/web/render.go
+++ b/internal/web/render.go
@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"github.com/lukaszkasprzak/lectio/internal/bible"
+	"github.com/lukaszkasprzak/lectio/internal/i18n"
 	"github.com/lukaszkasprzak/lectio/internal/liturgy"
 	"github.com/lukaszkasprzak/lectio/internal/render"
 )
@@ -203,7 +204,7 @@ func buildInterlinearViews(secs []liturgy.Section, versions []string, lectionary
 		}
 
 		if len(sets) == 0 {
-			view.Note = "(brak wersetów do zestawienia interlinearnego)"
+			view.Note = i18n.Get(lang).NoInterlinearVerses
 			views = append(views, view)
 			continue
 		}
diff --git a/internal/web/render_test.go b/internal/web/render_test.go
index ea44ed2..494cdcd 100644
--- a/internal/web/render_test.go
+++ b/internal/web/render_test.go
@@ -106,6 +106,22 @@ func TestRenderReadingsInterlinearNoVersifiedNote(t *testing.T) {
 	if strings.Contains(html, "ilverse") {
 		t.Errorf("expected no ilverse blocks when nothing resolves: %q", html)
 	}
+	if !strings.Contains(html, "brak wersetów do zestawienia interlinearnego") {
+		t.Errorf("pl no-verses note missing/wrong: %q", html)
+	}
+}
+
+// TestRenderReadingsInterlinearNoVersifiedNoteLang checks the interlinear
+// "no verses to align" note (finding §1) follows lang, not always Polish.
+func TestRenderReadingsInterlinearNoVersifiedNoteLang(t *testing.T) {
+	secs := []liturgy.Section{{Heading: "Bez odwołania", PartID: "ewangelia"}}
+	html := string(RenderReadings(secs, []string{"wuj"}, "new", "interlinear", "en"))
+	if !strings.Contains(html, "(no verses to align)") {
+		t.Errorf("en no-verses note missing/wrong: %q", html)
+	}
+	if strings.Contains(html, "brak wersetów") {
+		t.Errorf("en output should not carry the Polish no-verses note: %q", html)
+	}
 }
 
 // TestRenderReadingsLocalizesEN checks that lang="en" localises both the
diff --git a/internal/web/server.go b/internal/web/server.go
index 3b7102c..4c13576 100644
--- a/internal/web/server.go
+++ b/internal/web/server.go
@@ -188,6 +188,8 @@ type indexData struct {
 	// set from i18n.Get(cfg.UILanguage) -- index.html references its
 	// fields (e.g. {{.L.Lectionary}}) instead of hardcoded Polish text.
 	L i18n.UI
+	// Lang is cfg.UILanguage, rendered into <html lang="...">.
+	Lang string
 }
 
 type versionOpt struct {
@@ -245,6 +247,7 @@ func indexHandler(cfg config.Config) http.HandlerFunc {
 			Mono:        queryBool(r, "mono", cfg.WebMono),
 			Reading:     reading,
 			L:           i18n.Get(cfg.UILanguage),
+			Lang:        cfg.UILanguage,
 		}
 
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
@@ -269,15 +272,16 @@ func readingsHandler(cfg config.Config) http.HandlerFunc {
 }
 
 // renderOrError returns RenderReadings' fragment, or (on a readings.Load
-// error) a small escaped error paragraph -- readings.Load errors are
-// expected in normal operation (an unpublished date, no network while
-// online, ...) so the pane should show them, not 500.
+// error, or no sections at all for the date) a small escaped error
+// paragraph, localised via lang -- readings.Load errors are expected in
+// normal operation (an unpublished date, no network while online, ...) so
+// the pane should show them, not 500.
 func renderOrError(secs []liturgy.Section, versions []string, lectionary, display, lang string, err error) template.HTML {
 	if err != nil {
 		return template.HTML(`<p class="error">` + template.HTMLEscapeString(err.Error()) + `</p>`)
 	}
 	if len(secs) == 0 {
-		return template.HTML(`<p class="error">brak czytań na ten dzień</p>`)
+		return template.HTML(`<p class="error">` + template.HTMLEscapeString(i18n.Get(lang).NoReadingsDay) + `</p>`)
 	}
 	return RenderReadings(secs, versions, lectionary, display, lang)
 }
diff --git a/internal/web/server_test.go b/internal/web/server_test.go
index 25d21f4..32ee412 100644
--- a/internal/web/server_test.go
+++ b/internal/web/server_test.go
@@ -227,6 +227,53 @@ func TestServer(t *testing.T) {
 	})
 }
 
+// TestRenderOrErrorNoSectionsLang checks the "no readings at all for this
+// day" fragment (finding §1) follows lang instead of always being Polish.
+func TestRenderOrErrorNoSectionsLang(t *testing.T) {
+	html := string(renderOrError(nil, nil, "new", "horizontal", "en", nil))
+	if !strings.Contains(html, "no readings for this day") {
+		t.Errorf("en renderOrError(no secs) = %q, want it to contain %q", html, "no readings for this day")
+	}
+	if strings.Contains(html, "czyta") {
+		t.Errorf("en renderOrError(no secs) should not carry Polish wording: %q", html)
+	}
+
+	html = string(renderOrError(nil, nil, "new", "horizontal", "pl", nil))
+	if !strings.Contains(html, "brak czytań na ten dzień") {
+		t.Errorf("pl renderOrError(no secs) = %q, want it to contain %q", html, "brak czytań na ten dzień")
+	}
+}
+
+// TestIndexHTMLLangAttribute checks index.html's <html lang="..."> follows
+// cfg.UILanguage (finding §6) instead of being hardcoded "pl".
+func TestIndexHTMLLangAttribute(t *testing.T) {
+	html, err := os.ReadFile("../liturgy/testdata/2026-07-22.html")
+	if err != nil {
+		t.Fatal(err)
+	}
+	fixtureServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write(html)
+	}))
+	defer fixtureServer.Close()
+	liturgy.SetBaseURL(fixtureServer.URL + "/liturgia/%s/Ewangelia")
+	t.Setenv("XDG_CACHE_HOME", t.TempDir())
+
+	cfg := config.Default()
+	cfg.UILanguage = "en"
+	rec := httptest.NewRecorder()
+	NewServer(cfg).ServeHTTP(rec, httptest.NewRequest("GET", "/?date=2026-07-22&v=wuj", nil))
+	if !strings.Contains(rec.Body.String(), `<html lang="en">`) {
+		t.Errorf(`en index page missing <html lang="en">: %q`, rec.Body.String()[:min(400, rec.Body.Len())])
+	}
+
+	cfg.UILanguage = "pl"
+	rec = httptest.NewRecorder()
+	NewServer(cfg).ServeHTTP(rec, httptest.NewRequest("GET", "/?date=2026-07-22&v=wuj", nil))
+	if !strings.Contains(rec.Body.String(), `<html lang="pl">`) {
+		t.Errorf(`pl index page missing <html lang="pl">: %q`, rec.Body.String()[:min(400, rec.Body.Len())])
+	}
+}
+
 // TestChooseListener exercises chooseListener's port-selection logic
 // directly (no HTTP serving): port==0 prefers defaultWebPort (1099) and
 // falls back to a free OS port when 1099 is taken, and a non-zero port is
diff --git a/internal/web/templates/index.html b/internal/web/templates/index.html
index 8c9fd86..780224f 100644
--- a/internal/web/templates/index.html
+++ b/internal/web/templates/index.html
@@ -11,7 +11,7 @@
      included too; they override "date" via hx-vals. The theme <select>
      has no server round trip: it swaps the #theme <link>'s href directly. */}}
 <!doctype html>
-<html lang="pl">
+<html lang="{{.Lang}}">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">