[Client] Flat moderation headers and detail tab shape

cockatrice/src/interface/widgets/tabs/moderation_tab_style.h

@@ -0,0 +1,25 @@
+#ifndef MODERATION_TAB_STYLE_H
+#define MODERATION_TAB_STYLE_H
+
+#include <QProxyStyle>
+#include <qtmetamacros.h>
+
+/**
+ * Flat tab shapes for the moderation detail tabs (report queue detailTabs).
+ * Replaces the native tab frame with the palette Window background plus a
+ * 2px Highlight underline on the selected tab and a faint Highlight wash on
+ * hover. Labels (text, elide, focus) are left to the base style, so keyboard
+ * focus stays distinguishable.
+ */
+class ModerationTabStyle : public QProxyStyle
+{
+    Q_OBJECT
+public:
+    explicit ModerationTabStyle(QStyle *base = nullptr);
+    void drawControl(ControlElement element,
+                     const QStyleOption *option,
+                     QPainter *painter,
+                     const QWidget *widget = nullptr) const override;
+};
+
+#endif // MODERATION_TAB_STYLE_H