Close two blind spots in the contrast check

Last change found a folded player's stack sitting at 2.22:1, hidden for twenty rounds
behind an exemption. So I went looking for the other exemptions rather than waiting for
the next one to surface. There were two, and neither is hiding a live fault today --
which is worth saying plainly, because it means this is a fix to the instrument and not
to the tool.

Leaf elements only

    if (el.children.length > 0) return;   // leaf text only

An element's own text stopped being measured the moment a child was added to it. The
undo control went that way two changes ago, the day a <kbd> was appended to it: its
label became invisible to this check with no sign that anything had changed. Now it
measures an element's own text nodes and leaves the descendants to their own turn,
against their own colours.

aria-hidden as a contrast exemption

The bets layer is aria-hidden because the amounts on the chips are already announced by
the seat and the action bar, and repeating them would be noise. That is a good reason
to hide them from a screen reader and no reason at all to stop checking whether a
sighted dealer can read them -- and the chips are exactly what the felt is read for.
Two different questions were being answered by one attribute.

Nothing is exempt now. If something genuinely decorative turns up, it should say so in
its own words rather than borrowing an attribute that means something else. The
watermark that the exemption was written for is gone as of the change before last.

What the widened check finds

Nothing. Zero offenders at six viewports across touch and pointer contexts, and with
the sidebar panels and the rulings sheet open. Measured from rendered pixels, the two
things that had been invisible are comfortable: the bet chip amounts read 12.65 to
13.74:1 and the undo label 8.06:1.

So the fix is proved by injection instead. Colouring the bet chip amounts #3a3a3a now
reports three offenders at 1.80:1, and colouring the undo control #2f2f2f reports it at
1.13:1. Neither was reported before.

269 tests still passing, no console errors.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb

JoshHeaps.Net/Pages/Casino/TexasHoldem.cshtml

@@ -25,7 +25,6 @@
         <section id="tableSection">
             <div id="pokerTableWrap">
                 <div id="pokerTable">
-                    <div id="tableWatermark" aria-hidden="true">Texas Hold'em</div>
                     <div id="potBadge">
                         <span id="potBadgeLabel">Pot</span>
                         <span id="potBadgeAmount">$0</span>

JoshHeaps.Net/wwwroot/css/casino/holdem.css

@@ -357,21 +357,18 @@ button,
     justify-content: center;
 }
 
-#tableWatermark {
+/* The felt used to carry a "TEXAS HOLD'EM" wordmark across its middle. It came out
-    position: absolute;
+   from behind the pot badge in two pieces — measured at every seat count from two to
-    inset: 0;
+   ten, the middle 20% of it was covered, so the felt read "TEXAS  LD'EM" — and no
-    display: flex;
+   placement fixed that everywhere. Thirty per cent down cleared the badge on a desktop
-    align-items: center;
+   and landed on the seats of a phone's square felt (43-70% covered); a smaller mark at
-    justify-content: center;
+   20% or 78% was clean on desktop and tablet and no better on a phone; the bottom one
-    color: rgba(255, 255, 255, 0.06);
+   fell off the oval entirely at 360px. A square felt with six to nine seats has no
-    font-size: 2.4rem;
+   clear band wide enough for a word.
-    font-weight: 700;
+   
-    letter-spacing: 0.15em;
+   So it's gone. A watermark that looks broken is worse than no watermark, and the felt
-    text-transform: uppercase;
+   has a gradient, a rim, an inner gold line and a shadow to be a table with — plus a
-    text-align: center;
+   header saying "Texas Hold'em Dealer" a few inches above it. */
-    pointer-events: none;
-    user-select: none;
-}
 
 #potBadge {
     position: relative;
@@ -513,13 +510,53 @@ button,
 
 /* Sitting out, not gone: still a person the dealer may need to deal back in, so
    the name has to stay readable rather than fading almost to the felt. */
+/* Out of the hand, still readable.
+
+   Both of these used to fade the whole seat — opacity 0.5 folded, 0.58 sitting out —
+   and opacity on a box fades the text you still have to read along with the box you
+   wanted to push back. Measured off the rendered pixels at 11.5px text, where AA asks
+   for 4.5:1:
+
+     live     name 13.28   stack 4.75
+     folded   name  4.75   stack 2.22
+     sat out  name  7.00   stack 3.22
+
+   A folded player's stack is not decoration. It's what they'll have next hand and the
+   answer to "how much has Ben got?", and at 2.22:1 it was barely there.
+
+   So the box recedes and the text doesn't: a flatter, darker background and a muted
+   border say "not in this hand", while the name and the stack keep colours that
+   measure. The folded seat keeps its red border and the line through the name, which
+   is the part that actually names the state. */
+.seat.seatInactive,
+.seat.seatFolded {
+    background: linear-gradient(160deg, #232323, #171717);
+    border-color: rgba(255, 255, 255, 0.06);
+}
+
+/* A folded seat already says so twice — a red border and a line through the name — but
+   a seat that's sitting out said it only by being faint, and taking the faintness away
+   took the whole signal with it. A dashed edge is the same thing an empty chair wears,
+   which is right: neither is in this hand. The name and the stack tell them apart. */
 .seat.seatInactive {
-    opacity: 0.58;
+    border-style: dashed;
+    border-color: rgba(255, 255, 255, 0.22);
+}
+
+.seat.seatInactive .seatPuckName,
+.seat.seatFolded .seatPuckName {
+    color: #b0b0b0;
+}
+
+.seat.seatInactive .seatPuckStack,
+.seat.seatFolded .seatPuckStack,
+.seat.seatInactive .seatPuckTotal,
+.seat.seatFolded .seatPuckTotal {
+    color: #8f8f8f;
 }
 
 .seat.seatFolded {
     border-color: rgba(224, 123, 123, 0.4);
-    opacity: 0.5;
 }
 
 .seat.seatFolded .seatPuckName {
@@ -2172,11 +2209,12 @@ body.hasActionBar #holdemSidebar {
 
 /* The undo pill's key, inline rather than pinned to a corner — see actionBar.js. */
 .actionUndoKey {
+    /* See .actionKey below for why these are not fainter. */
     margin-left: 0.4rem;
     padding: 0 0.25rem;
     border-radius: 4px;
     border: 1px solid currentColor;
-    opacity: 0.55;
+    opacity: 0.75;
     font-family: inherit;
     font-size: 0.6rem;
     line-height: 1.4;
@@ -2184,6 +2222,10 @@ body.hasActionBar #holdemSidebar {
     pointer-events: none;
 }
 
+/* A key hint is small — 9.6px — so AA asks 4.5:1 of it, and at the opacity these used
+   to carry they measured 2.97 to 3.33 against their buttons. That's the same fault as
+   the folded seats above: a fade chosen for looks pushing text a dealer is meant to
+   read under the threshold. They're still quieter than the label they sit beside. */
 .actionKey {
     position: absolute;
     top: 5px;
@@ -2191,7 +2233,7 @@ body.hasActionBar #holdemSidebar {
     padding: 0 0.25rem;
     border-radius: 4px;
     border: 1px solid currentColor;
-    opacity: 0.4;
+    opacity: 0.75;
     font-family: inherit;
     font-size: 0.6rem;
     line-height: 1.4;
@@ -2845,10 +2887,6 @@ body.hasActionBar #toastHost {
         padding: 0.25rem 0.3rem;
     }
 
-    #tableWatermark {
-        font-size: 1.4rem;
-    }
-
     #potBadge {
         padding: 0.5rem 1.1rem;
     }

JoshHeaps.Net/wwwroot/js/casino/holdem/main.js

@@ -461,6 +461,17 @@ document.addEventListener("DOMContentLoaded", () => {
     // The one time the browser refuses to save, say so out loud as well as leaving the
     // standing warning in the Session panel. Set before the first render so a failure
     // during start-up is caught too.
+    // Another tab writing to the same table. Said once, with the way out attached —
+    // reloading here adopts whatever that tab has done, which is the only resolution
+    // that doesn't throw somebody's work away.
+    HoldemState.onOtherTab = () => {
+        Toast.show(
+            "This table is open in another tab. Whichever acts last wins.",
+            { actionLabel: "Reload", onAction: () => window.location.reload(), duration: 20000 });
+        Render.renderStorageWarning();
+    };
+    HoldemState.watchOtherTabs();
+
     HoldemState.onSaveFailed = () => {
         Toast.show(
             "This table isn't being saved — refreshing would lose it. Keep this tab open.",

JoshHeaps.Net/wwwroot/js/casino/holdem/render.js

@@ -761,13 +761,20 @@ const Render = {
     renderStorageWarning() {
         const host = document.getElementById("storageWarning");
         if (!host) return;
-        host.hidden = !HoldemState.saveFailed && !HoldemState.loadFailed;
+        host.hidden = !HoldemState.saveFailed && !HoldemState.loadFailed && !HoldemState.otherTabActive;
         if (host.hidden) return;
 
-        // Both can be true at once — a browser having trouble with storage tends to
+        // Any of these can be true at once — a browser having trouble with storage
-        // have it in both directions — and the one that explains an empty table goes
+        // tends to have it in both directions — and the one that explains an empty
-        // first, because that's the question the dealer is standing there asking.
+        // table goes first, because that's the question the dealer is standing there
+        // asking.
         const lines = [];
+        if (HoldemState.otherTabActive) {
+            lines.push(
+                "This table is open in another tab, and both are writing to it — " +
+                "whichever acts last wins, so work done in the other one can vanish. " +
+                "Close one, then reload this tab to pick up the table as it stands.");
+        }
         if (HoldemState.loadFailed) {
             lines.push(
                 "The saved table couldn't be read, so this one started empty. " +

JoshHeaps.Net/wwwroot/js/casino/holdem/state.js

@@ -84,6 +84,30 @@ const HoldemState = {
     // Where an unreadable save is kept instead of being written over.
     RECOVERY_KEY: "casino.holdem.state.v1.unreadable",
 
+    // True once another tab has written to this table. Two tabs each hold their own
+    // copy in memory and each save writes the whole thing, so the second one to act
+    // silently throws the first one's work away — measured: tab A deals and takes a
+    // call, tab B renames a seat, and the deal, the blinds and the call are gone with
+    // nothing said in either tab.
+    //
+    // Watched rather than merged. Replacing the table under a dealer's hands mid-hand
+    // would be its own hazard; knowing there are two of them is what they need.
+    otherTabActive: false,
+    onOtherTab: null,
+
+    // The browser fires this in every *other* tab, never the one that wrote, so our
+    // own saves can't trip it.
+    watchOtherTabs() {
+        if (typeof window === "undefined" || this.tabWatcher) return;
+        this.tabWatcher = event => {
+            if (event.key !== this.STORAGE_KEY) return;
+            if (this.otherTabActive) return;
+            this.otherTabActive = true;
+            if (typeof this.onOtherTab === "function") this.onOtherTab();
+        };
+        window.addEventListener("storage", this.tabWatcher);
+    },
+
     // True when there was a saved table and it couldn't be read. Same pair as
     // saveFailed above, for the same reason: the UI has to be able to say so.
     loadFailed: false,

tests/holdem/otherTab.test.js

@@ -0,0 +1,100 @@
+// Noticing that the same table is open twice.
+//
+// Two tabs each hold their own copy in memory and each save writes the whole thing,
+// so the second one to act throws the first one's work away. This doesn't merge them
+// — replacing a table under a dealer's hands mid-hand would be its own hazard — it
+// notices, which is what lets them decide.
+const test = require("node:test");
+const assert = require("node:assert");
+const { HoldemState } = require("./load");
+
+function withWindow() {
+    const listeners = [];
+    globalThis.window = {
+        addEventListener(type, fn) { if (type === "storage") listeners.push(fn); },
+        removeEventListener(type, fn) {
+            const i = listeners.indexOf(fn);
+            if (i >= 0) listeners.splice(i, 1);
+        },
+    };
+    return {
+        listeners,
+        fire(key) { listeners.forEach(fn => fn({ key })); },
+    };
+}
+
+test.beforeEach(() => {
+    HoldemState.otherTabActive = false;
+    HoldemState.onOtherTab = null;
+    HoldemState.tabWatcher = null;
+});
+
+test.after(() => {
+    delete globalThis.window;
+    HoldemState.otherTabActive = false;
+    HoldemState.onOtherTab = null;
+    HoldemState.tabWatcher = null;
+});
+
+test("a write to this table from elsewhere is noticed", () => {
+    const win = withWindow();
+    let told = 0;
+    HoldemState.onOtherTab = () => { told++; };
+    HoldemState.watchOtherTabs();
+
+    win.fire(HoldemState.STORAGE_KEY);
+
+    assert.equal(HoldemState.otherTabActive, true);
+    assert.equal(told, 1);
+});
+
+test("somebody else's storage key is not our business", () => {
+    const win = withWindow();
+    let told = 0;
+    HoldemState.onOtherTab = () => { told++; };
+    HoldemState.watchOtherTabs();
+
+    win.fire("some.other.app.state");
+    win.fire(HoldemState.RECOVERY_KEY);
+
+    assert.equal(HoldemState.otherTabActive, false);
+    assert.equal(told, 0);
+});
+
+test("told once, however many times the other tab acts", () => {
+    const win = withWindow();
+    let told = 0;
+    HoldemState.onOtherTab = () => { told++; };
+    HoldemState.watchOtherTabs();
+
+    for (let i = 0; i < 10; i++) win.fire(HoldemState.STORAGE_KEY);
+
+    assert.equal(told, 1);
+});
+
+test("watching twice doesn't listen twice", () => {
+    const win = withWindow();
+    HoldemState.watchOtherTabs();
+    HoldemState.watchOtherTabs();
+    HoldemState.watchOtherTabs();
+
+    assert.equal(win.listeners.length, 1);
+});
+
+test("no listener set is not an error", () => {
+    const win = withWindow();
+    HoldemState.onOtherTab = null;
+    HoldemState.watchOtherTabs();
+
+    assert.doesNotThrow(() => win.fire(HoldemState.STORAGE_KEY));
+    assert.equal(HoldemState.otherTabActive, true);
+});
+
+test("no window at all is not an error", () => {
+    // The same modules are loaded in Node by the test harness.
+    delete globalThis.window;
+    HoldemState.tabWatcher = null;
+
+    assert.doesNotThrow(() => HoldemState.watchOtherTabs());
+    assert.equal(HoldemState.otherTabActive, false);
+});

tests/holdem/uiAudit.js

@@ -349,6 +349,16 @@ const LayoutAudit = {
         });
     },
 
+    // Every element between this one and the document, so an opacity set on a
+    // container can be seen from the text inside it.
+    *ancestors(el) {
+        let node = el.parentElement;
+        while (node) {
+            yield node;
+            node = node.parentElement;
+        }
+    },
+
     contrast({ minimum = 4.5, largeMinimum = 3, selector = null } = {}) {
         const offenders = [];
         const unmeasured = [];
@@ -358,19 +368,50 @@ const LayoutAudit = {
             : [...document.querySelectorAll("*")];
 
         nodes.forEach(el => {
-            if (el.children.length > 0) return;               // leaf text only
+            // An element's *own* text, not its descendants' — they get measured on
-            const text = (el.textContent || "").trim();
+            // their own turn, against their own colour.
+            //
+            // This used to be "leaf elements only", which quietly stopped measuring
+            // anything the moment a child was added to it. The undo control went that
+            // way the day a <kbd> was appended to it: its label became invisible to
+            // this check, with no sign that anything had changed.
+            const text = [...el.childNodes]
+                .filter(node => node.nodeType === 3)
+                .map(node => node.textContent)
+                .join(" ")
+                .trim();
             if (!text) return;
             const rect = el.getBoundingClientRect();
             if (rect.width === 0 || rect.height === 0) return;
             const style = getComputedStyle(el);
             if (style.visibility === "hidden" || style.display === "none") return;
-            if (parseFloat(style.opacity) < 0.99) return;     // faded on purpose
+            // Faded text used to be skipped outright as "faded on purpose", and that
-            // Decoration is exempt by definition: the watermark on the felt is meant
+            // exemption hid a real fault: the folded and sat-out seats dimmed their
-            // to be barely there, and holding it to a reading threshold would mean
+            // whole box with opacity, so a folded player's stack measured 2.22:1 at
-            // making it not a watermark. Marked aria-hidden so screen readers skip it
+            // 11.5px and this check never looked at it. Something invisible is still
-            // too, which is the same claim expressed where it also does some good.
+            // exempt — there's nothing to read at zero — but anything in between is
-            if (el.closest("[aria-hidden='true']")) return;
+            // reported as unmeasured rather than passed over in silence, because a
+            // number nobody checked is not the same as a number that's fine.
+            const opacity = parseFloat(style.opacity);
+            if (opacity <= 0.02) return;
+            const faded = opacity < 0.99 ||
+                [...this.ancestors(el)].some(a => parseFloat(getComputedStyle(a).opacity) < 0.99);
+            if (faded) {
+                unmeasured.push(`${this.describe(el)} :: faded (opacity ${opacity}), contrast not checked`);
+                return;
+            }
+            // aria-hidden used to exempt text here, on the grounds that decoration
+            // marked for screen readers was decoration for everyone. Those are two
+            // different questions and the answer differs: the bet chips on the felt are
+            // aria-hidden because their amounts are already announced by the seat and
+            // the action bar, and repeating them would be noise — but they are exactly
+            // what a sighted dealer reads the felt for, and this check had stopped
+            // looking at them. Hiding something from one audience is not a claim about
+            // whether the other audience can read it.
+            //
+            // Nothing is exempt now. If something genuinely decorative turns up, it
+            // should say so in its own words rather than borrowing an attribute that
+            // means something else.
 
             const fgRaw = this.parseColour(style.color);
             if (!fgRaw) return;