+constexpr gint PAN_CAL_POPUP_BORDER = 1;
+constexpr guint8 PAN_CAL_POPUP_ALPHA = 255;
+constexpr PanColor PAN_CAL_POPUP_COLOR{220, 220, 220, PAN_CAL_POPUP_ALPHA};
+constexpr PanColor PAN_CAL_POPUP_BORDER_COLOR{0, 0, 0, PAN_CAL_POPUP_ALPHA};
+constexpr PanColor PAN_CAL_POPUP_TEXT_COLOR{0, 0, 0, 255};
+
+constexpr gint PAN_CAL_DAY_WIDTH = 100;
+constexpr gint PAN_CAL_DAY_HEIGHT = 80;
+constexpr gint PAN_CAL_DAY_BORDER = 2;
+constexpr guint8 PAN_CAL_DAY_ALPHA = 220;
+constexpr PanColor PAN_CAL_DAY_COLOR{255, 255, 255, PAN_CAL_DAY_ALPHA};
+constexpr PanColor PAN_CAL_DAY_BORDER_COLOR{0, 0, 0, PAN_CAL_DAY_ALPHA};
+constexpr PanColor PAN_CAL_DAY_TEXT_COLOR{0, 0, 0, 255};
+
+constexpr gint PAN_CAL_MONTH_BORDER = 4;
+constexpr guint8 PAN_CAL_MONTH_ALPHA = 200;
+constexpr PanColor PAN_CAL_MONTH_COLOR{255, 255, 255, PAN_CAL_MONTH_ALPHA};
+constexpr PanColor PAN_CAL_MONTH_BORDER_COLOR{0, 0, 0, PAN_CAL_MONTH_ALPHA};
+constexpr PanColor PAN_CAL_MONTH_TEXT_COLOR{0, 0, 0, 255};
+
+constexpr gint PAN_CAL_DOT_SIZE = 3;
+constexpr gint PAN_CAL_DOT_GAP = 2;