feat: implement modern dark theme and loading screen redesign

- Redesign loading screen progress bar with gradient animation
- Update loading screen typography using Segoe UI
- Add comprehensive dark theme styling to main window
- Modernize menu, toolbar, and dock widget appearances

1 files changed, 85 insertions, 0 deletions

diff --git a/src/citron/main.ui b/src/citron/main.ui
index cd893c757..573f02af4 100644
--- a/src/citron/main.ui
+++ b/src/citron/main.ui
@@ -23,6 +23,91 @@
   <property name="dockNestingEnabled">
    <bool>true</bool>
   </property>
+  <property name="styleSheet">
+   <string notr="true">QMainWindow {
+    background-color: #2D2D2D;
+}
+
+QMenuBar {
+    background-color: #333333;
+    color: #E0E0E0;
+    border-bottom: 1px solid #404040;
+    padding: 2px;
+}
+
+QMenuBar::item {
+    padding: 4px 8px;
+    background: transparent;
+    border-radius: 4px;
+}
+
+QMenuBar::item:selected {
+    background: #404040;
+}
+
+QMenuBar::item:pressed {
+    background: #505050;
+}
+
+QMenu {
+    background-color: #333333;
+    border: 1px solid #404040;
+    padding: 4px;
+}
+
+QMenu::item {
+    padding: 6px 24px 6px 12px;
+    color: #E0E0E0;
+    border-radius: 4px;
+}
+
+QMenu::item:selected {
+    background-color: #404040;
+}
+
+QMenu::separator {
+    height: 1px;
+    background: #404040;
+    margin: 4px 0px;
+}
+
+QStatusBar {
+    background-color: #333333;
+    color: #E0E0E0;
+    border-top: 1px solid #404040;
+}
+
+QDockWidget {
+    border: 1px solid #404040;
+    titlebar-close-icon: url(close.png);
+}
+
+QDockWidget::title {
+    background: #333333;
+    padding: 6px;
+    color: #E0E0E0;
+}
+
+QToolBar {
+    background: #333333;
+    border: none;
+    spacing: 3px;
+    padding: 3px;
+}
+
+QToolButton {
+    border-radius: 4px;
+    padding: 4px;
+}
+
+QToolButton:hover {
+    background-color: #404040;
+}
+
+QToolButton:pressed {
+    background-color: #505050;
+}</string>
+  </property>
   <widget class="QWidget" name="centralwidget">
    <layout class="QHBoxLayout" name="horizontalLayout">
     <property name="leftMargin">