Apply nmea_client dark theme across all tabs and plots

Color palette taken directly from nmea_client/gui/plot_widget.py:
- Background #1a1a2e / #12121e, borders #2a2a4a/#3a3a5e,
  text #aaaacc/#ddddee, connected #4CAF50, error #F44336
- Trace colors: Material palette (blue, red, green, orange, …)
- Plot widget background overridden from "white" to #12121e
- pyqtgraph foreground set to #aaaacc

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

gui_client.py

@@ -30,10 +30,54 @@ from PyQt5.QtWidgets import (
 
 import pyqtgraph as pg
 
-pg.setConfigOption("background", "w")
+pg.setConfigOption("background", "#12121e")
-pg.setConfigOption("foreground", "k")
+pg.setConfigOption("foreground", "#aaaacc")
 
 MAX_PLOT_POINTS  = 200
+
+DARK_STYLE = """
+QWidget                        { background:#1a1a2e; color:#aaaacc; font-size:12px; }
+QMainWindow                    { background:#1a1a2e; }
+QTabWidget::pane               { border:1px solid #2a2a4a; background:#1a1a2e; }
+QTabBar::tab                   { background:#12121e; color:#aaaacc; padding:5px 12px;
+                                 border:1px solid #2a2a4a; border-bottom:none; }
+QTabBar::tab:selected          { background:#1a1a2e; color:#ddddee; }
+QTabBar::tab:hover             { background:#2a2a4a; }
+QGroupBox                      { border:1px solid #2a2a4a; border-radius:4px;
+                                 margin-top:8px; padding-top:8px; color:#aaaacc; }
+QGroupBox::title               { subcontrol-origin:margin; left:8px; color:#aaaacc; }
+QLabel                         { color:#aaaacc; background:transparent; }
+QLineEdit, QSpinBox            { background:#12121e; border:1px solid #3a3a5e;
+                                 border-radius:3px; color:#ddddee; padding:2px 4px; }
+QLineEdit:focus, QSpinBox:focus{ border:1px solid #555577; }
+QSpinBox::up-button,
+QSpinBox::down-button          { background:#2a2a4a; border:none; }
+QPushButton                    { background:#2a2a4a; color:#aaaacc; border:1px solid #3a3a5e;
+                                 border-radius:3px; padding:4px 10px; }
+QPushButton:hover              { background:#3a3a5e; }
+QPushButton:pressed            { background:#12121e; }
+QPushButton:disabled           { color:#555577; }
+QComboBox                      { background:#12121e; border:1px solid #3a3a5e;
+                                 border-radius:3px; color:#ddddee; padding:2px 4px; }
+QComboBox::drop-down           { border:none; width:16px; }
+QComboBox QAbstractItemView    { background:#1a1a2e; color:#ddddee;
+                                 selection-background-color:#2a2a4a; }
+QTreeWidget                    { background:#12121e; alternate-background-color:#1a1a2e;
+                                 color:#aaaacc; border:1px solid #2a2a4a; }
+QTreeWidget::item:selected     { background:#2a2a4a; color:#ddddee; }
+QHeaderView::section           { background:#12121e; color:#aaaacc;
+                                 border:1px solid #2a2a4a; padding:4px; }
+QScrollArea                    { border:none; }
+QScrollBar:vertical            { background:#12121e; width:10px; margin:0; }
+QScrollBar::handle:vertical    { background:#3a3a5e; border-radius:4px; min-height:20px; }
+QScrollBar::handle:vertical:hover { background:#555577; }
+QScrollBar:horizontal          { background:#12121e; height:10px; margin:0; }
+QScrollBar::handle:horizontal  { background:#3a3a5e; border-radius:4px; min-width:20px; }
+QScrollBar::handle:horizontal:hover { background:#555577; }
+QScrollBar::add-line,
+QScrollBar::sub-line           { width:0; height:0; }
+QStatusBar                     { background:#12121e; color:#aaaacc; }
+"""
 _SETTINGS_PATH   = Path.home() / ".config" / "we_monitor" / "plot_settings.json"
 
 # Maps full dotted trace key → short display label used in chips, legends and
@@ -165,7 +209,7 @@ class ConnectorTab(QWidget):
         form.addRow(btn_row)
 
         self._status = QLabel("Disconnected")
-        self._status.setStyleSheet("color: gray;")
+        self._status.setStyleSheet("color: #9E9E9E;")
         form.addRow("Status:", self._status)
 
         layout.addWidget(grp)
@@ -181,7 +225,7 @@ class ConnectorTab(QWidget):
         self._host.setEnabled(False)
         self._port.setEnabled(False)
         self._status.setText(f"Connected  →  {host}:{port}")
-        self._status.setStyleSheet("color: green; font-weight: bold;")
+        self._status.setStyleSheet("color: #4CAF50; font-weight: bold;")
 
     def set_disconnected(self, reason: str = ""):
         self._btn.setText("Connect")
@@ -189,10 +233,10 @@ class ConnectorTab(QWidget):
         self._port.setEnabled(True)
         if reason:
             self._status.setText(f"Disconnected  ({reason})")
-            self._status.setStyleSheet("color: red;")
+            self._status.setStyleSheet("color: #F44336;")
         else:
             self._status.setText("Disconnected")
-            self._status.setStyleSheet("color: gray;")
+            self._status.setStyleSheet("color: #9E9E9E;")
 
 
 # ── Dashboard tab ─────────────────────────────────────────────────────────────
@@ -204,7 +248,7 @@ class DashboardTab(QWidget):
 
         self._ts = QLabel("Last update: —")
         self._ts.setAlignment(Qt.AlignRight)
-        self._ts.setStyleSheet("color: gray; font-size: 11px;")
+        self._ts.setStyleSheet("color: #9E9E9E; font-size: 11px;")
         layout.addWidget(self._ts)
 
         self._tree = QTreeWidget()
@@ -225,7 +269,7 @@ class DashboardTab(QWidget):
 
         bold = QFont()
         bold.setBold(True)
-        domain_color = QColor("#1a4d99")
+        domain_color = QColor("#aaaacc")
 
         for domain, domain_data in snapshot.items():
             if domain == "ts" or not isinstance(domain_data, dict):
@@ -295,7 +339,8 @@ class DashboardTab(QWidget):
 class PlotTab(QWidget):
     NUM_PLOTS  = 8
     MAX_TRACES = 4
-    COLORS     = ["#1f77b4", "#ff7f0e", "#2ca02c", "#d62728"]
+    COLORS     = ["#2196F3", "#F44336", "#4CAF50", "#FF9800",
+                  "#9C27B0", "#00BCD4", "#FFEB3B", "#795548"]
 
     def __init__(self):
         super().__init__()
@@ -361,7 +406,7 @@ class PlotTab(QWidget):
 
             # plot
             pw = pg.PlotWidget(
-                background="white",
+                background="#12121e",
                 axisItems={"bottom": pg.DateAxisItem(orientation="bottom")},
             )
             pw.showGrid(x=True, y=True, alpha=0.3)
@@ -414,7 +459,7 @@ class PlotTab(QWidget):
         btn.setStyleSheet(
             f"QPushButton {{ background:{color}; color:white; border-radius:3px;"
             f" padding:1px 6px; font-size:11px; }}"
-            f"QPushButton:hover {{ background:#888; }}"
+            f"QPushButton:hover {{ background:#555577; }}"
         )
         btn.clicked.connect(lambda: self._remove_trace(plot_idx, key))
         self._chip_bars[plot_idx].addWidget(btn)
@@ -614,6 +659,7 @@ class MainWindow(QMainWindow):
 def main():
     app = QApplication(sys.argv)
     app.setStyle("Fusion")
+    app.setStyleSheet(DARK_STYLE)
     win = MainWindow()
     win.show()
     sys.exit(app.exec_())