Add custom theming

config_test.go

@@ -87,6 +87,39 @@ up = ["ctrl+k"]
 	}
 }
 
+func TestLoadConfigParsesCustomTheme(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "config.toml")
+	content := `
+theme = "custom"
+
+[custom_theme]
+base = "catppuccin-mocha"
+mode = "dark"
+title = "#112233"
+selection_background = "#223344"
+author_palette = ["#334455", "#445566"]
+syntax_theme = "gruvbox"
+`
+	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	got, err := loadConfig(path, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := validateConfig(got); err != nil {
+		t.Fatal(err)
+	}
+	if got.Theme != "custom" ||
+		got.CustomTheme.Base != "catppuccin-mocha" ||
+		got.CustomTheme.Title != "#112233" ||
+		got.CustomTheme.SelectionBackground != "#223344" ||
+		len(got.CustomTheme.AuthorPalette) != 2 ||
+		got.CustomTheme.SyntaxTheme != "gruvbox" {
+		t.Fatalf("custom theme config = %#v", got.CustomTheme)
+	}
+}
+
 func TestValidateConfigRejectsEmptyKeyBinding(t *testing.T) {
 	config := defaultConfig()
 	config.KeyBindings.Navigation.Down = nil