Fix text color on light-background dialogs and popups

Set QWidget base background to dark so all dialogs, message boxes,
input dialogs, and file dialogs inherit the dark theme instead of
defaulting to Windows grey with unreadable white text on top.
Added explicit dark styling for QDialog, QMessageBox, QInputDialog,
QFileDialog, QDialogButtonBox, QComboBox dropdowns, and QFrame.
Labels and checkboxes use transparent background to show through
to their parent container correctly.

resources/styles/default.qss

@@ -1,10 +1,71 @@
 /* Setec Partition Wizard - Default Stylesheet */
 
+/* ============================================================
+   Base dark theme — all main window widgets get white text
+   on dark backgrounds.
+   Dialogs, message boxes, and system popups are explicitly
+   given dark backgrounds so white text stays readable.
+   ============================================================ */
+
+QWidget {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
 QMainWindow {
     background-color: #1e1e2e;
     color: #ffffff;
 }
 
+/* ============================================================
+   Dialogs — explicitly dark so popups don't get grey Windows
+   backgrounds with white text painted over them
+   ============================================================ */
+
+QDialog {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+QMessageBox {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+QMessageBox QLabel {
+    color: #ffffff;
+    background-color: transparent;
+}
+
+QInputDialog {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+QFileDialog {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+QFileDialog QLabel {
+    color: #ffffff;
+    background-color: transparent;
+}
+
+QColorDialog {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+QFontDialog {
+    background-color: #1e1e2e;
+    color: #ffffff;
+}
+
+/* ============================================================
+   Tabs
+   ============================================================ */
+
 QTabWidget::pane {
     border: 1px solid #45475a;
     background-color: #1e1e2e;
@@ -30,7 +91,11 @@ QTabBar::tab:hover:!selected {
     background-color: #3b3d52;
 }
 
-QTreeView, QTableView, QListView {
+/* ============================================================
+   Views
+   ============================================================ */
+
+QTreeView, QTableView, QListView, QListWidget, QTreeWidget {
     background-color: #181825;
     color: #ffffff;
     border: 1px solid #45475a;
@@ -39,10 +104,22 @@ QTreeView, QTableView, QListView {
     alternate-background-color: #1e1e2e;
 }
 
-QTreeView::item:hover, QTableView::item:hover {
+QTreeView::item:hover, QTableView::item:hover,
+QListView::item:hover, QListWidget::item:hover {
     background-color: #313244;
 }
 
+QTreeView::item:selected, QTableView::item:selected,
+QListView::item:selected, QListWidget::item:selected {
+    background-color: #45475a;
+    color: #ffffff;
+}
+
+QHeaderView {
+    background-color: #313244;
+    color: #ffffff;
+}
+
 QHeaderView::section {
     background-color: #313244;
     color: #ffffff;
@@ -50,6 +127,10 @@ QHeaderView::section {
     border: 1px solid #45475a;
 }
 
+/* ============================================================
+   Buttons
+   ============================================================ */
+
 QPushButton {
     background-color: #45475a;
     color: #ffffff;
@@ -67,6 +148,12 @@ QPushButton:pressed {
     background-color: #313244;
 }
 
+QPushButton:disabled {
+    background-color: #2a2a3a;
+    color: #6e7080;
+    border-color: #45475a;
+}
+
 QPushButton#applyButton {
     background-color: #d4a574;
     color: #1e1e2e;
@@ -82,6 +169,30 @@ QPushButton#cancelButton {
     color: #1e1e2e;
 }
 
+/* Dialog box standard buttons (OK, Cancel, Yes, No) */
+QDialogButtonBox QPushButton {
+    background-color: #45475a;
+    color: #ffffff;
+    border: 1px solid #585b70;
+    border-radius: 4px;
+    padding: 5px 16px;
+    min-width: 70px;
+}
+
+QDialogButtonBox QPushButton:hover {
+    background-color: #585b70;
+}
+
+QDialogButtonBox QPushButton:default {
+    background-color: #d4a574;
+    color: #1e1e2e;
+    border-color: #b08050;
+}
+
+/* ============================================================
+   Progress bar
+   ============================================================ */
+
 QProgressBar {
     background-color: #313244;
     border: 1px solid #45475a;
@@ -95,6 +206,10 @@ QProgressBar::chunk {
     border-radius: 3px;
 }
 
+/* ============================================================
+   Menus
+   ============================================================ */
+
 QMenuBar {
     background-color: #181825;
     color: #ffffff;
@@ -102,6 +217,7 @@ QMenuBar {
 
 QMenuBar::item:selected {
     background-color: #45475a;
+    color: #ffffff;
 }
 
 QMenu {
@@ -110,10 +226,30 @@ QMenu {
     border: 1px solid #45475a;
 }
 
+QMenu::item {
+    color: #ffffff;
+    padding: 4px 20px 4px 20px;
+}
+
 QMenu::item:selected {
     background-color: #45475a;
+    color: #ffffff;
 }
 
+QMenu::item:disabled {
+    color: #6e7080;
+}
+
+QMenu::separator {
+    height: 1px;
+    background-color: #45475a;
+    margin: 4px 8px;
+}
+
+/* ============================================================
+   Toolbar / Status bar
+   ============================================================ */
+
 QToolBar {
     background-color: #181825;
     border-bottom: 1px solid #45475a;
@@ -127,83 +263,224 @@ QStatusBar {
     border-top: 1px solid #45475a;
 }
 
-QSplitter::handle {
+QStatusBar QLabel {
-    background-color: #45475a;
+    color: #ffffff;
+    background-color: transparent;
 }
 
+/* ============================================================
+   Group box
+   ============================================================ */
+
 QGroupBox {
     border: 1px solid #45475a;
     border-radius: 4px;
     margin-top: 8px;
     padding-top: 8px;
     color: #ffffff;
+    background-color: #1e1e2e;
 }
 
 QGroupBox::title {
     subcontrol-origin: margin;
     left: 10px;
     padding: 0 4px;
+    color: #ffffff;
 }
 
-QLineEdit, QSpinBox, QComboBox {
+/* ============================================================
+   Input widgets
+   ============================================================ */
+
+QLineEdit, QSpinBox, QDoubleSpinBox {
     background-color: #313244;
     color: #ffffff;
     border: 1px solid #45475a;
     border-radius: 4px;
     padding: 4px 8px;
+    selection-background-color: #45475a;
+    selection-color: #ffffff;
 }
 
-QLineEdit:focus, QSpinBox:focus, QComboBox:focus {
+QLineEdit:focus, QSpinBox:focus, QDoubleSpinBox:focus {
     border-color: #d4a574;
 }
 
-QToolTip {
+QLineEdit:disabled, QSpinBox:disabled, QDoubleSpinBox:disabled {
+    background-color: #2a2a3a;
+    color: #6e7080;
+}
+
+QLineEdit:read-only {
+    background-color: #252535;
+    color: #a0a0b0;
+}
+
+QComboBox {
     background-color: #313244;
     color: #ffffff;
     border: 1px solid #45475a;
-    padding: 4px;
+    border-radius: 4px;
+    padding: 4px 8px;
+    min-width: 60px;
 }
 
+QComboBox:focus {
+    border-color: #d4a574;
+}
+
+QComboBox:disabled {
+    background-color: #2a2a3a;
+    color: #6e7080;
+}
+
+QComboBox::drop-down {
+    border: none;
+    width: 20px;
+}
+
+QComboBox QAbstractItemView {
+    background-color: #1e1e2e;
+    color: #ffffff;
+    border: 1px solid #45475a;
+    selection-background-color: #45475a;
+    selection-color: #ffffff;
+    outline: none;
+}
+
+/* Spin box arrow buttons */
+QSpinBox::up-button, QSpinBox::down-button,
+QDoubleSpinBox::up-button, QDoubleSpinBox::down-button {
+    background-color: #45475a;
+    border: none;
+    width: 16px;
+}
+
+QSpinBox::up-button:hover, QSpinBox::down-button:hover,
+QDoubleSpinBox::up-button:hover, QDoubleSpinBox::down-button:hover {
+    background-color: #585b70;
+}
+
+/* ============================================================
+   Splitter / separators
+   ============================================================ */
+
+QSplitter::handle {
+    background-color: #45475a;
+}
+
+/* ============================================================
+   Labels
+   ============================================================ */
+
 QLabel {
     color: #ffffff;
+    background-color: transparent;
 }
 
+/* ============================================================
+   Check boxes and radio buttons
+   ============================================================ */
+
 QCheckBox, QRadioButton {
     color: #ffffff;
+    background-color: transparent;
+    spacing: 6px;
 }
 
+QCheckBox:disabled, QRadioButton:disabled {
+    color: #6e7080;
+}
+
+/* ============================================================
+   Text editors
+   ============================================================ */
+
 QTextEdit, QPlainTextEdit {
     background-color: #181825;
     color: #ffffff;
     border: 1px solid #45475a;
+    selection-background-color: #45475a;
+    selection-color: #ffffff;
 }
 
+/* ============================================================
+   Tooltips
+   ============================================================ */
+
+QToolTip {
+    background-color: #313244;
+    color: #ffffff;
+    border: 1px solid #45475a;
+    padding: 4px 6px;
+}
+
+/* ============================================================
+   Scroll bars
+   ============================================================ */
+
 QScrollBar:vertical {
     background-color: #181825;
     width: 12px;
+    border: none;
 }
 
 QScrollBar::handle:vertical {
     background-color: #45475a;
     border-radius: 4px;
     min-height: 20px;
+    margin: 2px;
 }
 
 QScrollBar::handle:vertical:hover {
     background-color: #585b70;
 }
 
+QScrollBar::add-line:vertical, QScrollBar::sub-line:vertical {
+    height: 0px;
+}
+
 QScrollBar:horizontal {
     background-color: #181825;
     height: 12px;
+    border: none;
 }
 
 QScrollBar::handle:horizontal {
     background-color: #45475a;
     border-radius: 4px;
     min-width: 20px;
+    margin: 2px;
 }
 
 QScrollBar::handle:horizontal:hover {
     background-color: #585b70;
 }
+
+QScrollBar::add-line:horizontal, QScrollBar::sub-line:horizontal {
+    width: 0px;
+}
+
+/* ============================================================
+   Frame / containers used inside dialogs
+   ============================================================ */
+
+QFrame {
+    background-color: transparent;
+    color: #ffffff;
+}
+
+QFrame[frameShape="4"],  /* HLine */
+QFrame[frameShape="5"]   /* VLine */ {
+    background-color: #45475a;
+    border: none;
+    max-height: 1px;
+}
+
+QStackedWidget {
+    background-color: #1e1e2e;
+}
+
+QAbstractScrollArea {
+    background-color: #181825;
+}