1 files changed, 26 insertions, 0 deletions
diff --git a/src/cardlayout.cpp b/src/cardlayout.cpp
index 0febb4b..3719591 100644
--- a/src/cardlayout.cpp
+++ b/src/cardlayout.cpp
@@ -107,6 +107,32 @@ QFont CardLayout::smallFont(const QFont &cardFont)
     return small;
 }
 
+QFont CardLayout::siblingFont(const QFont &cardFont)
+{
+    // A FRACTION of the card's font, not a fixed number of points off it.
+    //
+    // Subtracting one point was the first attempt and the user reported the
+    // tiers as indistinguishable. The reason is arithmetic: their desktop is
+    // 14pt, so the two chip tiers were 13 and 12, a 7% step. Subtraction gives
+    // a step whose size depends on the desktop font, which is exactly backwards
+    // — it is largest where the text is already small enough to be fragile.
+    //
+    // 0.70 of the card font, against smallFont()'s one point off, so on a 14pt
+    // desktop the tiers are 13 and 10. Chosen with the user against rendered
+    // sizes rather than picked.
+    constexpr qreal kSiblingScale = 0.70;
+
+    QFont small = cardFont;
+    // pointSizeF() returns -1 for a font set in PIXELS, which qt6ct does, and
+    // scaling -1 asks for an invalid size that Qt silently ignores, leaving
+    // both tiers identical. Same split as smallFont(), same reason.
+    if (small.pointSizeF() > 0.0)
+        small.setPointSizeF(qMax(6.0, cardFont.pointSizeF() * kSiblingScale));
+    else if (small.pixelSize() > 0)
+        small.setPixelSize(qMax(8, qRound(cardFont.pixelSize() * kSiblingScale)));
+    return small;
+}
+
 int CardLayout::heightFor(const QFont &font)
 {
     const QFontMetrics metrics(font);