diff --git a/src/qt/palladiumamountfield.cpp b/src/qt/palladiumamountfield.cpp
index 0b90fb9..2c44899 100644
--- a/src/qt/palladiumamountfield.cpp
+++ b/src/qt/palladiumamountfield.cpp
@@ -190,6 +190,19 @@ protected:
         return QAbstractSpinBox::event(event);
     }
 
+    void changeEvent(QEvent *event)
+    {
+        if (event->type() == QEvent::StyleChange ||
+            event->type() == QEvent::PaletteChange ||
+            event->type() == QEvent::FontChange)
+        {
+            // Invalidate cached size hint when theme/style changes
+            cachedMinimumSizeHint = QSize();
+            updateGeometry();
+        }
+        QAbstractSpinBox::changeEvent(event);
+    }
+
     StepEnabled stepEnabled() const
     {
         if (isReadOnly()) // Disable steps when AmountSpinBox is read-only
diff --git a/src/qt/palladiumgui.cpp b/src/qt/palladiumgui.cpp
index 5f51df2..68b6bff 100644
--- a/src/qt/palladiumgui.cpp
+++ b/src/qt/palladiumgui.cpp
@@ -1544,14 +1544,22 @@ void PalladiumGUI::toggleTheme()
         // 1. Standard Theme (Weiß)
         qApp->setStyleSheet("");
         qApp->setPalette(style()->standardPalette());
-        
+
         // 2. Speichern, dass er aus ist
         settings.setValue("darkModeEnabled", false);
-        
+
         if (modalOverlay) {
             modalOverlay->setStyleSheet("");
         }
     }
+
+    // Force geometry recalculation for all widgets after theme change
+    // This ensures proper sizing when switching between native (light) and stylesheet (dark) rendering
+    for (QWidget *widget : qApp->allWidgets()) {
+        if (widget && widget->isVisible()) {
+            widget->updateGeometry();
+        }
+    }
 }
 
 void PalladiumGUI::checkUpdate()
diff --git a/src/qt/res/styles/dark.qss b/src/qt/res/styles/dark.qss
index 69f0315..0acf55a 100644
--- a/src/qt/res/styles/dark.qss
+++ b/src/qt/res/styles/dark.qss
@@ -432,6 +432,8 @@ PalladiumAmountField QAbstractSpinBox {
     background-color: #1E1E1E;
     color: #FFFFFF;
     border: 1px solid #4A4A4A;
+    min-height: 26px;
+    padding: 2px;
 }
 
 PalladiumAmountField QAbstractSpinBox:hover {
@@ -444,6 +446,49 @@ PalladiumAmountField QAbstractSpinBox:focus {
     background-color: #252525;
 }
 
+/* Fix for spinbox up/down buttons visibility */
+PalladiumAmountField QAbstractSpinBox::up-button,
+PalladiumAmountField QAbstractSpinBox::down-button {
+    background-color: #2A2A2A;
+    border: 1px solid #3A3A3A;
+    width: 16px;
+}
+
+PalladiumAmountField QAbstractSpinBox::up-button:hover,
+PalladiumAmountField QAbstractSpinBox::down-button:hover {
+    background-color: #3A3A3A;
+    border: 1px solid #4A4A4A;
+}
+
+PalladiumAmountField QAbstractSpinBox::up-button:pressed,
+PalladiumAmountField QAbstractSpinBox::down-button:pressed {
+    background-color: #007BFF;
+}
+
+PalladiumAmountField QAbstractSpinBox::up-arrow {
+    image: none;
+    width: 8px;
+    height: 8px;
+    border-left: 4px solid transparent;
+    border-right: 4px solid transparent;
+    border-bottom: 6px solid #808080;
+}
+
+PalladiumAmountField QAbstractSpinBox::down-arrow {
+    image: none;
+    width: 8px;
+    height: 8px;
+    border-left: 4px solid transparent;
+    border-right: 4px solid transparent;
+    border-top: 6px solid #808080;
+}
+
+PalladiumAmountField QAbstractSpinBox::up-arrow:hover,
+PalladiumAmountField QAbstractSpinBox::down-arrow:hover {
+    border-bottom-color: #A0A0A0;
+    border-top-color: #A0A0A0;
+}
+
 PalladiumAmountField QComboBox {
     background-color: #1E1E1E;
     color: #E0E0E0;