feat: text zoom shortcuts and high-contrast resize lines

- Ctrl+plus / Ctrl+minus / Ctrl+0 (and View menu entries) scale the QSS
  FONT_* ladder and the application default font together; the scale is
  clamped to 0.8-1.6 and persisted in QSettings appearance/font_scale.
- Resize gutters keep a 5px hover/drag region but paint only a 2px line
  with a 1px shadow (hard-stop gradients per orientation).
- WCAG contrast fixes: separators were 1.0-1.2:1 against every theme
  background, now >=3.25:1 (dark theme gold @70%); scrollbar handle
  1.17:1 -> 3.38:1; unselected tab text on the sky gradient 2.07:1 ->
  4.71:1 via TAB_IDLE_TEXT.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/aare/gui/main_window.py

@@ -31,6 +31,7 @@ from PySide6.QtGui import (
     QActionGroup,
     QColor,
     QCursor,
+    QFont,
     QGuiApplication,
     QImage,
     QKeySequence,
@@ -100,6 +101,7 @@ from aare.gui.styles import (
     APP_BACKGROUND,
     DARK_TEXT,
     DOCK_CONTENT_LEFT_PAD,
+    FONT_SCALE_STEP,
     SEPARATOR_HINT_DELAY_MS,
     THEME_BLUEBIRD,
     THEME_FADE_MS,
@@ -107,7 +109,9 @@ from aare.gui.styles import (
     THEME_SUNSET,
     admin_tip_qss,
     build_app_stylesheet,
+    font_scale,
     qcolor,
+    set_font_scale,
 )
 
 # Threads
@@ -2002,6 +2006,15 @@ class MainWindow(QMainWindow):
             app.setPalette(palette)
         else:
             app.setPalette(self._default_palette)
+        # Text zoom, part 2: the QSS FONT_* ladder only reaches widgets the app
+        # sheet names — everything else renders in the app default font, so
+        # scale that too or body text ignores Ctrl+plus/minus.
+        if not hasattr(self, "_default_app_font"):
+            self._default_app_font = app.font()
+        font = QFont(self._default_app_font)
+        if font_scale() != 1.0:
+            font.setPointSizeF(self._default_app_font.pointSizeF() * font_scale())
+        app.setFont(font)
         self.setStyleSheet(build_app_stylesheet(self._theme_mode))
         # State colors are painted in code per DAQ tick — QSS can't reach them.
         self.beamline_state_panel.set_theme(self._theme_mode)
@@ -2038,10 +2051,23 @@ class MainWindow(QMainWindow):
         # change (styles.py: "original"->"sunrise", "portrait"->"sunset").
         saved = {"original": THEME_SUNRISE, "portrait": THEME_SUNSET}.get(saved, saved)
         self._theme_mode = saved
+        set_font_scale(float(settings.value("appearance/font_scale", 1.0, type=float)))
 
     def _save_theme_settings(self) -> None:
         settings = QSettings("PSI", "AareGUI")
         settings.setValue("appearance/theme", self._theme_mode)
+        settings.setValue("appearance/font_scale", font_scale())
+
+    def _change_font_zoom(self, direction: int) -> None:
+        """Ctrl+plus / Ctrl+minus / Ctrl+0 accessibility zoom: step the FONT_*
+        ladder scale and rebuild the app stylesheet (same repolish path as a
+        theme switch, so the whole UI rescales in one pass)."""
+        # round: repeated 0.1 float steps otherwise drift (1.2000000000000002)
+        set_font_scale(
+            1.0 if direction == 0 else round(font_scale() + direction * FONT_SCALE_STEP, 2)
+        )
+        self._save_theme_settings()
+        self._apply_theme()
 
     @Slot()
     def use_legacy_theme(self) -> None:
@@ -2113,6 +2139,24 @@ class MainWindow(QMainWindow):
         view_menu.addAction(self._use_bluebird_theme_action)
         view_menu.addAction(self._use_portrait_theme_action)
         view_menu.addSeparator()
+
+        # Accessibility text zoom. Ctrl+= alias: StandardKey.ZoomIn is
+        # Ctrl+Shift+= on some platforms and users expect plain Ctrl+plus.
+        bigger_text_action = QAction("Bigger Text", self)
+        bigger_text_action.setShortcuts(
+            [*QKeySequence.keyBindings(QKeySequence.StandardKey.ZoomIn), QKeySequence("Ctrl+=")]
+        )
+        bigger_text_action.triggered.connect(lambda: self._change_font_zoom(1))
+        view_menu.addAction(bigger_text_action)
+        smaller_text_action = QAction("Smaller Text", self)
+        smaller_text_action.setShortcuts(QKeySequence.StandardKey.ZoomOut)
+        smaller_text_action.triggered.connect(lambda: self._change_font_zoom(-1))
+        view_menu.addAction(smaller_text_action)
+        reset_text_action = QAction("Reset Text Size", self)
+        reset_text_action.setShortcut(QKeySequence("Ctrl+0"))
+        reset_text_action.triggered.connect(lambda: self._change_font_zoom(0))
+        view_menu.addAction(reset_text_action)
+        view_menu.addSeparator()
         view_menu.addAction(self._portrait_mode_action)
         view_menu.addAction(self._enter_automation_view_action)
         view_menu.addSeparator()

src/aare/gui/styles.py

@@ -113,16 +113,44 @@ DOCK_CONTENT_LEFT_PAD = 10
 # banner's bottom edge line.
 BANNER_TAB_GAP = 6
 
-# Resize-line hint: dock separators stay invisible until the mouse rests on
-# one for SEPARATOR_HINT_DELAY_MS (or a drag starts) — then only the exact
-# separator under the cursor fills with SEPARATOR_HINT. The rest/drag gate
-# lives in MainWindow.event(); the QSS :hover part picks the one separator.
-SEPARATOR_HINT = "rgba(168, 178, 192, 30%)"  # scrollbar-track grey @50%
-# Idle fill so the resize line is findable before the hover rest — 10% of the
-# hover alpha. Any base QSS fill replaces the native dotted grip; accepted.
-SEPARATOR_IDLE = "rgba(168, 178, 192, 10%)"
+# Resize lines: the hover rest (SEPARATOR_HINT_DELAY_MS, gate in
+# MainWindow.event(); the QSS :hover part picks the one separator) darkens the
+# exact separator under the cursor to SEPARATOR_HINT.
+# Accessibility (WCAG 1.4.11, >=3:1 non-text contrast): the old
+# rgba(168,178,192) fills measured 1.0-1.2:1 against every theme background —
+# invisible. Solid slate: idle #47536a >=3.25:1, hover #3f4a5f >=3.74:1
+# against gradient top/mid/bottom and panel white.
+SEPARATOR_HINT = "#3f4a5f"
+SEPARATOR_IDLE = "#47536a"
 SEPARATOR_HINT_DELAY_MS = 66  # int, used in code, not QSS
 
+# The gutter keeps this full width for the mouse; only a 2px line + 1px
+# shadow is painted inside it (a solid 5px bar read too heavy). 5px is a
+# first guess — adjust here if the grab target feels off.
+SEPARATOR_REGION = "5px"
+SEPARATOR_SHADOW = "rgba(31, 41, 59, 25%)"
+
+
+def _separator_gradient(line: str, shadow: str, axis: str) -> str:
+    """Paint of a resize gutter: transparent 1px, shadow 1px, line 2px,
+    shadow 1px — hard gradient stops at 1/5 steps of SEPARATOR_REGION.
+    axis "x" runs the gradient left->right (an upright line), "y" top->down
+    (a lying line)."""
+    x2, y2 = ("1", "0") if axis == "x" else ("0", "1")
+    return (
+        f"qlineargradient(x1:0, y1:0, x2:{x2}, y2:{y2},"
+        f" stop:0 transparent, stop:0.19 transparent,"
+        f" stop:0.2 {shadow}, stop:0.39 {shadow},"
+        f" stop:0.4 {line}, stop:0.79 {line},"
+        f" stop:0.8 {shadow}, stop:1 {shadow})"
+    )
+
+
+SEP_IDLE_X = _separator_gradient(SEPARATOR_IDLE, SEPARATOR_SHADOW, "x")
+SEP_IDLE_Y = _separator_gradient(SEPARATOR_IDLE, SEPARATOR_SHADOW, "y")
+SEP_HINT_X = _separator_gradient(SEPARATOR_HINT, SEPARATOR_SHADOW, "x")
+SEP_HINT_Y = _separator_gradient(SEPARATOR_HINT, SEPARATOR_SHADOW, "y")
+
 # Theme-switch screenshot cross-fade duration (int ms, used in code).
 THEME_FADE_MS = 250
 
@@ -226,7 +254,14 @@ DARK_DISABLED = "#3c4a66"  # disabled — disabled fills
 # Accents — gold is IDENTITY (titles, highlights), blue is ACTION (primary
 # buttons); the site keeps the two apart on purpose:
 DARK_ACCENT = "#e0913f"  # gold
-DARK_SEPARATOR_IDLE = "rgba(224, 145, 63, 10%)"  # DARK_ACCENT @10%, idle resize line
+# DARK_ACCENT @70%: 10% measured 1.16:1 on DARK_BG (invisible); 70% blends to
+# >=3.74:1 — same WCAG 1.4.11 floor as the light-theme separators.
+DARK_SEPARATOR_IDLE = "rgba(224, 145, 63, 70%)"
+DARK_SEPARATOR_SHADOW = "rgba(0, 0, 0, 45%)"
+DARK_SEP_IDLE_X = _separator_gradient(DARK_SEPARATOR_IDLE, DARK_SEPARATOR_SHADOW, "x")
+DARK_SEP_IDLE_Y = _separator_gradient(DARK_SEPARATOR_IDLE, DARK_SEPARATOR_SHADOW, "y")
+DARK_SEP_HINT_X = _separator_gradient(DARK_ACCENT, DARK_SEPARATOR_SHADOW, "x")
+DARK_SEP_HINT_Y = _separator_gradient(DARK_ACCENT, DARK_SEPARATOR_SHADOW, "y")
 DARK_ACCENT_HOVER = "#eaa253"  # accent2 — brighter gold
 DARK_ACCENT_FILL = "#89b4fa"  # action blue
 DARK_ACCENT_FILL_HOVER = "#9ec2fb"  # +10% white, derived (site has no step)
@@ -271,6 +306,10 @@ HINT_TEXT = "#9ca0b0"  # baton dialog fine print (latte overlay0)
 HEADING_TEXT = "#4c4f69"  # card headings (latte text)
 SUBTLE_TEXT = "#5c5f77"  # card body text (latte subtext1)
 MUTED_TEXT = "#6c6f85"  # neutral chip / idle step text (latte subtext0)
+# Unselected tab labels: tabs also sit on the sky gradient, where MUTED_TEXT
+# is 2.07:1 — under the 4.5:1 WCAG text floor. This slate reads 4.71:1 on the
+# gradient top and stays muted next to TEXT.
+TAB_IDLE_TEXT = "#2f3b52"
 FAINT_TEXT = "#8c8fa1"  # pending/skipped step text (latte overlay1)
 SHADOW = "#000000"  # drop shadows & tutorial scrim; alpha stays at call site
 
@@ -471,6 +510,9 @@ LEGEND_BG = "#eff1f5"  # base
 LEGEND_TEXT = "#4c4f69"  # text
 TOOLTIP_TEXT = "#4c4f69"  # camera coords tooltip pen — NOT the QToolTip popup
 SCALE_BAR_GREY = "#8c8fa1"  # hover HUD scale bar (Latte overlay1 grey)
+MARK_TOOLTIP_GOLD = "#df8e1d"  # yellow
+MARK_TOOLTIP_ORANGE = "#fe640b"  # peach
+MARK_TOOLTIP_RED = "#d20f39"  # red
 MARK_BADGE_BG = "#fe640b"  # peach
 
 # Prediction class overlay colors. The old pure-green vs CSS-green split
@@ -500,11 +542,22 @@ BOOKMARK_COLORS = {
     "lime": "#179299",  # teal — Latte has one green; teal keeps the pair distinct
 }
 
-# -- Busy overlay: PSI red for every busy state, blue for robot cooling ------
+# -- Busy overlay (per-source color coding) ---------------------------------
 # Catppuccin Latte accents; BORDER/DOT are 25%/20% mixes toward Latte base.
 BUSY_YELLOW = "#df8e1d"  # yellow
 BUSY_YELLOW_BORDER = "#ebd8bf"
 BUSY_YELLOW_DOT = "#ecddca"
+BUSY_YELLOW_TEXT_DARK = "#4c4f69"  # text
+BUSY_PURPLE = "#8839ef"  # mauve
+BUSY_PURPLE_BORDER = "#d5c3f4"
+BUSY_PURPLE_DOT = "#daccf4"
+BUSY_RED_BADGE = "#d20f39"  # red
+BUSY_RED_FILL = "#d20f39"  # red
+BUSY_RED_BORDER = "#e8b8c6"
+BUSY_RED_DOT = "#e9c4cf"
+BUSY_ORANGE = "#fe640b"  # peach
+BUSY_ORANGE_BORDER = "#f3ceba"
+BUSY_ORANGE_DOT = "#f2d5c6"
 BUSY_BLUE = "#1e66f5"  # blue
 BUSY_BLUE_BORDER = "#bbcef5"
 BUSY_BLUE_DOT = "#c5d5f5"
@@ -550,6 +603,27 @@ FONT_LABEL = "14px"  # form labels, secondary text — always bold
 FONT_HINT = "12px"  # hints
 FONT_FINE = "11px"  # fine print, queue titles
 
+# -- Font zoom (Ctrl+plus / Ctrl+minus, accessibility) ----------------------
+# Whole-app text scale applied to the FONT_* ladder when the QSS is built, so
+# one re-apply of the stylesheet rescales every rule. Floats, so _palette()'s
+# str filter never picks them up as colors.
+FONT_SCALE_MIN = 0.8
+FONT_SCALE_MAX = 1.6
+FONT_SCALE_STEP = 0.1
+_font_scale = 1.0
+
+
+def font_scale() -> float:
+    return _font_scale
+
+
+def set_font_scale(scale: float) -> None:
+    # Clamped: below 0.8 the fine-print sizes fall under 9px (unreadable),
+    # above 1.6 the fixed-height banner rows start clipping their text.
+    global _font_scale
+    _font_scale = max(FONT_SCALE_MIN, min(FONT_SCALE_MAX, scale))
+
+
 # -- Hover tooltips (the QToolTip popup; styled borderless) -----------------
 TOOLTIP_BG = "#f7f9fc"
 TOOLTIP_FG = "#263043"
@@ -577,11 +651,12 @@ def admin_tip_qss(theme: str) -> str:
 SLIDER_FILL = "#8ba3c7"
 
 # -- Scrollbars (rounded, no arrows) ----------------------------------------
-# Flipped on request: the track is now the darker grey and the draggable
-# handle the light one; hover therefore lightens further instead of darkening.
+# Accessibility re-flip (WCAG 1.4.11): the light-on-light pairing measured
+# 1.17:1 handle-vs-track — the handle was not findable. Dark handle on the
+# light track gives 3.38:1 (5.02:1 on hover); hover darkens again.
 SCROLLBAR_TRACK = "#E4E4E4"
-SCROLLBAR_HANDLE = "#D4D4D4"
-SCROLLBAR_HANDLE_HOVER = "#C4C4C4"
+SCROLLBAR_HANDLE = "#7a7a7a"
+SCROLLBAR_HANDLE_HOVER = "#5f5f5f"
 
 # Disabled-input fill and the slider colors used to borrow the scrollbar
 # knobs; own knobs so the scrollbar flip above doesn't drag them along.
@@ -598,7 +673,15 @@ FLAT_CARD_RADIUS = "0px"  # recovery + console-log cards stay square
 def _palette() -> dict[str, str]:
     # Why: one substitution mapping instead of ~40 kwargs per stylesheet, and
     # a renamed/missing constant fails loudly (KeyError) instead of silently.
-    return {k.lower(): v for k, v in globals().items() if k.isupper() and isinstance(v, str)}
+    mapping = {k.lower(): v for k, v in globals().items() if k.isupper() and isinstance(v, str)}
+    if _font_scale != 1.0:
+        # ponytail: only the app-sheet FONT_* ladder scales; widgets that
+        # import FONT_* into local f-string QSS keep 1.0 — port them to the
+        # app sheet if zoom must reach them.
+        for k, v in mapping.items():
+            if k.startswith("font_") and v.endswith("px"):
+                mapping[k] = f"{round(int(v[:-2]) * _font_scale)}px"
+    return mapping
 
 
 def qcolor(color: str, alpha: int | None = None):
@@ -1026,7 +1109,10 @@ def _sunrise_stylesheet(overrides: dict[str, str] | None = None) -> str:
         border-top-right-radius: 4px;
         padding: 4px 14px;
         margin-top: 3px;
-        color: $muted_text;
+        /* tab_idle_text, not muted_text: camera tabs sit on the sky
+           gradient where muted grey measured 2.07:1 (WCAG text floor is
+           4.5:1); the darker slate is 4.71:1 there, 11.2:1 on panels. */
+        color: $tab_idle_text;
     }
 
     QTabBar::tab:selected {
@@ -1082,24 +1168,42 @@ def _sunrise_stylesheet(overrides: dict[str, str] | None = None) -> str:
         font-weight: 700;
     }
 
-    /* Idle resize lines: faint fill (10% of the hover alpha) so the drag
-       target is findable without hunting. This base fill replaces the
-       native dotted grip — traded away on purpose for discoverability. */
-    QMainWindow::separator, QSplitter::handle {
-        background: $separator_idle;
+    /* Resize gutters: the mouse keeps the full $separator_region, but only
+       a 2px line + 1px shadow paints (gradients in _separator_gradient).
+       An upright line needs the x-gradient: that is a :vertical main-window
+       separator but a :horizontal splitter handle (handle orientation
+       follows the splitter, not the bar). */
+    QMainWindow::separator {
+        width: $separator_region;
+        height: $separator_region;
+        background: transparent;
     }
+    QMainWindow::separator:vertical, QSplitter::handle:horizontal {
+        background: $sep_idle_x;
+    }
+    QMainWindow::separator:horizontal, QSplitter::handle:vertical {
+        background: $sep_idle_y;
+    }
+    QSplitter::handle:horizontal { width: $separator_region; }
+    QSplitter::handle:vertical { height: $separator_region; }
 
     /* Resize-line hint — the separatorHint property is flipped by
        MainWindow.event() after a 1s hover rest or on press; :hover limits
        the fill to the exact separator being dragged. */
-    QMainWindow[separatorHint="true"]::separator:hover {
-        background: $separator_hint;
+    QMainWindow[separatorHint="true"]::separator:vertical:hover {
+        background: $sep_hint_x;
+    }
+    QMainWindow[separatorHint="true"]::separator:horizontal:hover {
+        background: $sep_hint_y;
     }
 
     /* Splitter handles (prediction metrics) are plain child widgets the
        property gate above doesn't reach — immediate hover/press hint. */
-    QSplitter::handle:hover, QSplitter::handle:pressed {
-        background: $separator_hint;
+    QSplitter::handle:horizontal:hover, QSplitter::handle:horizontal:pressed {
+        background: $sep_hint_x;
+    }
+    QSplitter::handle:vertical:hover, QSplitter::handle:vertical:pressed {
+        background: $sep_hint_y;
     }
 
     QFrame#beamlineControls,
@@ -1743,16 +1847,32 @@ def _sunset_stylesheet() -> str:
     }
 
     /* Idle + hover resize lines, dark flavor — see the light-theme note. */
-    QMainWindow::separator, QSplitter::handle {
-        background: $dark_separator_idle;
+    QMainWindow::separator {
+        width: $separator_region;
+        height: $separator_region;
+        background: transparent;
+    }
+    QMainWindow::separator:vertical, QSplitter::handle:horizontal {
+        background: $dark_sep_idle_x;
+    }
+    QMainWindow::separator:horizontal, QSplitter::handle:vertical {
+        background: $dark_sep_idle_y;
+    }
+    QSplitter::handle:horizontal { width: $separator_region; }
+    QSplitter::handle:vertical { height: $separator_region; }
+
+    QMainWindow[separatorHint="true"]::separator:vertical:hover {
+        background: $dark_sep_hint_x;
+    }
+    QMainWindow[separatorHint="true"]::separator:horizontal:hover {
+        background: $dark_sep_hint_y;
     }
 
-    QMainWindow[separatorHint="true"]::separator:hover {
-        background: $dark_accent;
+    QSplitter::handle:horizontal:hover, QSplitter::handle:horizontal:pressed {
+        background: $dark_sep_hint_x;
     }
-
-    QSplitter::handle:hover, QSplitter::handle:pressed {
-        background: $dark_accent;
+    QSplitter::handle:vertical:hover, QSplitter::handle:vertical:pressed {
+        background: $dark_sep_hint_y;
     }
 
     /* Plain scroll containers stay frameless. */
@@ -1925,5 +2045,15 @@ if __name__ == "__main__":
     for _theme in (THEME_SUNRISE, THEME_SUNSET, THEME_BLUEBIRD):
         assert "$" not in build_app_stylesheet(_theme)
     assert APP_BACKGROUND not in build_app_stylesheet(THEME_BLUEBIRD)
+    # Font zoom: the FONT_* ladder must follow the scale, and the scale must
+    # clamp to its documented bounds.
+    set_font_scale(1.3)
+    assert "font-size: 21px" in build_app_stylesheet(THEME_SUNRISE)  # title 16->21
+    set_font_scale(99.0)
+    assert font_scale() == FONT_SCALE_MAX
+    set_font_scale(0.0)
+    assert font_scale() == FONT_SCALE_MIN
+    set_font_scale(1.0)
+    assert "font-size: 16px" in build_app_stylesheet(THEME_SUNRISE)
     # This line was added by Claude. But I would do the same. So all gude.
     print("gude")

tests/unit/gui/test_main_window.py

@@ -2,8 +2,9 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 from PySide6.QtCore import QSettings, Qt
-from PySide6.QtWidgets import QDockWidget
+from PySide6.QtWidgets import QApplication, QDockWidget
 
+from aare.gui import styles
 from aare.gui.main_window import MainWindow
 from aare.gui.styles import THEME_BLUEBIRD, THEME_SUNRISE, THEME_SUNSET
 
@@ -502,6 +503,50 @@ def test_theme_settings_migrate_and_slots_switch(qtbot, mock_ui_state):
         assert win._theme_mode == THEME_SUNRISE
 
 
+def test_font_zoom_steps_clamps_and_resets(qtbot, mock_ui_state):
+    with (
+        patch("requests.get"),
+        patch("aare.gui.main_window.DAQWorker"),
+        patch("aare.gui.main_window.PredictionSubscriber"),
+        patch("aare.gui.main_window.VideoThread"),
+        patch("aare.gui.main_window.JFJochDBusClient"),
+        patch("aare.gui.main_window.jwt.decode") as mock_jwt,
+    ):
+        mock_jwt.return_value = {
+            "sub": "testuser",
+            "staff": True,
+            "pgroups": ["p123"],
+            "session": 15,
+        }
+        win = _make_window(qtbot)
+
+        settings = QSettings("PSI", "AareGUI")
+        saved = settings.value("appearance/font_scale")
+        try:
+            base_pt = win._default_app_font.pointSizeF()
+            win._change_font_zoom(1)
+            assert styles.font_scale() == pytest.approx(1.1)
+            # Part 2 of the zoom: the app default font scales with the ladder.
+            app = QApplication.instance()
+            assert isinstance(app, QApplication)  # narrow from QCoreApplication|None
+            assert app.font().pointSizeF() == pytest.approx(base_pt * 1.1)
+            for _ in range(20):
+                win._change_font_zoom(1)
+            assert styles.font_scale() == styles.FONT_SCALE_MAX
+            win._change_font_zoom(0)
+            assert styles.font_scale() == 1.0
+            assert app.font().pointSizeF() == pytest.approx(base_pt)
+            for _ in range(20):
+                win._change_font_zoom(-1)
+            assert styles.font_scale() == styles.FONT_SCALE_MIN
+        finally:
+            styles.set_font_scale(1.0)
+            if saved is None:
+                settings.remove("appearance/font_scale")
+            else:
+                settings.setValue("appearance/font_scale", saved)
+
+
 def test_restore_window_state_heals_all_hidden_docks(qtbot, mock_ui_state):
     with (
         patch("requests.get"),