Style account switcher to match the current theme (#4817)

src/widgets/AccountSwitchPopup.cpp

@@ -1,5 +1,7 @@
 #include "widgets/AccountSwitchPopup.hpp"
 
+#include "common/Literals.hpp"
+#include "singletons/Theme.hpp"
 #include "widgets/AccountSwitchWidget.hpp"
 #include "widgets/dialogs/SettingsDialog.hpp"
 
@@ -9,6 +11,8 @@
 
 namespace chatterino {
 
+using namespace literals;
+
 AccountSwitchPopup::AccountSwitchPopup(QWidget *parent)
     : BaseWindow({BaseWindow::TopMost, BaseWindow::Frameless,
                   BaseWindow::DisableLayoutSave},
@@ -39,6 +43,48 @@ AccountSwitchPopup::AccountSwitchPopup(QWidget *parent)
     this->getLayoutContainer()->setLayout(vbox);
 
     this->setScaleIndependantSize(200, 200);
+    this->themeChangedEvent();
+}
+
+void AccountSwitchPopup::themeChangedEvent()
+{
+    BaseWindow::themeChangedEvent();
+
+    auto *t = getTheme();
+    auto color = [](const QColor &c) {
+        return c.name(QColor::HexArgb);
+    };
+    this->setStyleSheet(uR"(
+        QListView {
+            color: %1;
+            background: %2;
+        }
+        QListView::item:hover {
+            background: %3;
+        }
+        QListView::item:selected {
+            background: %4;
+        }
+
+        QPushButton {
+            background: %5;
+            color: %1;
+        }
+        QPushButton:hover {
+            background: %3;
+        }
+        QPushButton:pressed {
+            background: %6;
+        }
+
+        chatterino--AccountSwitchPopup {
+            background: %7;
+        }
+    )"_s.arg(color(t->window.text), color(t->splits.header.background),
+             color(t->splits.header.focusedBackground), color(t->accent),
+             color(t->tabs.regular.backgrounds.regular),
+             color(t->tabs.selected.backgrounds.regular),
+             color(t->window.background)));
 }
 
 void AccountSwitchPopup::refresh()