diff --git a/README.txt b/README.txt
index f433e4a..1e1a5e2 100644
--- a/README.txt
+++ b/README.txt
@@ -4,7 +4,7 @@ Tags: woocommerce, discount, email, shipping, coupon
 Requires at least: 5.8
 Tested up to: 7.1
 Requires PHP: 7.4
-Stable tag: 1.5.2
+Stable tag: 1.5.3
 WC requires at least: 6.0
 WC tested up to: 11.1.0
 License: GPLv2 or later
diff --git a/ci/plugin.conf b/ci/plugin.conf
index 3c86062..cf20677 100644
--- a/ci/plugin.conf
+++ b/ci/plugin.conf
@@ -75,7 +75,11 @@ RELEASE_REPO=kw/nolimit-discounts-dist
 # The frozen hash is therefore a family-wide fact, not a local one, and taking
 # a new one is something all six do in the same window.
 #
-# 678f1f03 = contract 1.2.1: the glyph is centred with flex inside an explicit
+# 471b0a2a = contract 1.2.2: the icon box is sized 100%/100% instead of a
+# hardcoded 36x34. WordPress declares that parent three times and they
+# disagree (36x34 open, 35x30 folded, 34x30 under 960px), so a fixed number is
+# right in one state and wrong in the two a laptop is usually in.
+# Withdrawn: 678f1f03 = 1.2.1: the glyph is centred with flex inside an explicit
 # 36x34 box instead of inheriting WordPress's 7px padding, which made the
 # pseudo-element 42px tall inside a 34px parent and pushed the sign above
 # centre. Kristian reported it from the live shop.
@@ -87,4 +91,4 @@ RELEASE_REPO=kw/nolimit-discounts-dist
 # backslashes, hex digits and spaces, so there is nothing left to leave the
 # string with. Verified here against seven hostile inputs.
 # Earlier frozen hashes: 184cebdc = 1.1.0, f4862d5c = 1.0.0.
-WPMGR_MENU_SHA=678f1f0368fcc781ce34c0289f6470a6bb0491bc32c0598e859c7ceba66e5e2a
+WPMGR_MENU_SHA=471b0a2aab47b6b7f8d839ac8b12d60637bbe2c07df86f7e40089c677fbab3cc
diff --git a/includes/shared-menu.php b/includes/shared-menu.php
index 9a87024..b62c271 100644
--- a/includes/shared-menu.php
+++ b/includes/shared-menu.php
@@ -69,7 +69,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 }
 
 if ( ! defined( 'WPMGR_MENU_VERSION' ) ) {
-	define( 'WPMGR_MENU_VERSION', '1.2.1' );
+	define( 'WPMGR_MENU_VERSION', '1.2.2' );
 }
 
 if ( ! defined( 'WPMGR_MENU_SLUG' ) ) {
@@ -164,19 +164,41 @@ if ( ! function_exists( 'wpmgr_ensure_menu' ) ) {
 	 * 🔴 The box is WordPress's own, measured rather than guessed, and the
 	 * glyph is centred in it geometrically rather than nudged.
 	 *
-	 * wp-admin/css/admin-menu.css sets `#adminmenu div.wp-menu-image` to
-	 * 36x34, and `div.wp-menu-image:before` to `padding: 7px 0` — which is
-	 * exactly 7 + 20 + 7 for a 20px dashicon on `line-height: 1`. The first
-	 * version of this rule set `line-height: 1.4` and inherited that padding,
-	 * making the line box 28px and the whole pseudo-element 42px inside a 34px
-	 * parent. Kristian reported the result: the glyph sitting above centre.
+	 * wp-admin/css/admin-menu.css sets `div.wp-menu-image:before` to
+	 * `padding: 7px 0` — exactly 7 + 20 + 7 for a 20px dashicon on
+	 * `line-height: 1` in a 34px box. The first version of this rule set
+	 * `line-height: 1.4` and inherited that padding, making the line box 28px
+	 * and the whole pseudo-element 42px inside a 34px parent. Kristian
+	 * reported the result: the glyph sitting above centre.
 	 *
-	 * So: reproduce the 36x34 box, drop the padding that only existed to
-	 * position a 20px line inside it, and centre with flex. That matters more
-	 * for an arbitrary glyph than for a dashicon — U+221E sits on the maths
-	 * axis rather than filling its em box, so any rule that positions by
-	 * line-height and padding is positioning the box and hoping about the
-	 * glyph. `align-items: center` centres what is actually drawn.
+	 * So: drop the padding that only existed to position a 20px line, and
+	 * centre with flex. That matters more for an arbitrary glyph than for a
+	 * dashicon — U+221E sits on the maths axis rather than filling its em box,
+	 * so any rule that positions by line-height and padding is positioning the
+	 * box and hoping about the glyph. `align-items: center` centres what is
+	 * actually drawn, which is also what keeps working if anyone returns
+	 * something else from `wpmgr_menu_glyph`.
+	 *
+	 * 🔴 `100%%`, not `100%`. This is a printf format string, so a literal
+	 * per-cent sign has to be doubled — and the first version of the
+	 * percentage fix did not, which is a **fatal on every admin page**:
+	 * "Uncaught ValueError: Unknown format specifier". Three sessions agreed
+	 * on that file after reading it, linting it and running PHPCS over it, and
+	 * all three are blind to this: the syntax is valid and the standard has
+	 * nothing to say. Only running the function finds it, and it was the site
+	 * test that did. The fixed-pixel version could not have had this fault,
+	 * so it arrived with the improvement.
+	 *
+	 * 🔴 The size is `100%`, not the 36x34 the desktop menu happens to be.
+	 * That stylesheet declares the parent THREE times and they disagree:
+	 * `#adminmenu div.wp-menu-image` is 36x34, `.folded #adminmenu
+	 * div.wp-menu-image` is 35x30, and under `@media (max-width: 960px)`
+	 * `.auto-fold #adminmenu div.wp-menu-image` is 34x30. A pseudo-element
+	 * fixed at 36x34 is therefore correct on a wide screen with the menu open
+	 * and 4px too tall in both of the other states — which are the states a
+	 * laptop is in. Percentages resolve against whichever parent is in force,
+	 * so there is no number here to be right about. Measured by reading that
+	 * stylesheet, not by eye.
 	 */
 	function wpmgr_menu_glyph_style() {
 		$glyph = apply_filters( 'wpmgr_menu_glyph', '∞' );
@@ -187,7 +209,7 @@ if ( ! function_exists( 'wpmgr_ensure_menu' ) ) {
 
 		// phpcs:disable WordPress.Security.EscapeOutput.OutputNotEscaped -- the slug is reduced to [a-z0-9_-] and the glyph to CSS numeric escapes; both are escaped for the context they are printed in, which is CSS rather than HTML.
 		printf(
-			'<style>#adminmenu .toplevel_page_%1$s .wp-menu-image::before{content:"%2$s";font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:20px;font-weight:400;display:flex;align-items:center;justify-content:center;width:36px;height:34px;padding:0;line-height:1}</style>',
+			'<style>#adminmenu .toplevel_page_%1$s .wp-menu-image::before{content:"%2$s";font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:20px;font-weight:400;display:flex;align-items:center;justify-content:center;width:100%%;height:100%%;padding:0;line-height:1}</style>',
 			preg_replace( '/[^a-z0-9_-]/', '', strtolower( WPMGR_MENU_SLUG ) ),
 			wpmgr_css_escape( $glyph )
 		);
diff --git a/tests/smoke.php b/tests/smoke.php
index 0dc1e8f..49adf63 100644
--- a/tests/smoke.php
+++ b/tests/smoke.php
@@ -317,6 +317,38 @@ wc_edm_is(
 	isset( $wc_edm_mine[0]['colour'] ) ? $wc_edm_mine[0]['colour'] : null
 );
 
+// 🔴 The style function is INVOKED, not read. A version of this file shipped
+// with `width:100%` inside a printf format string, where a literal per-cent
+// must be doubled — an uncaught ValueError on every admin page. Three sessions
+// read it, php -l was clean, PHPCS was clean, and two browsers agreed about
+// the CSS, because all of them were fed the stylesheet by hand rather than
+// through the PHP that produces it. Only running it finds this.
+if ( function_exists( 'wpmgr_menu_glyph_style' ) ) {
+	$wc_edm_threw = '';
+	ob_start();
+	try {
+		wpmgr_menu_glyph_style();
+	} catch ( \Throwable $e ) {
+		$wc_edm_threw = get_class( $e ) . ': ' . $e->getMessage();
+	}
+	$wc_edm_style = ob_get_clean();
+
+	wc_edm_ok(
+		'emitting the menu glyph style throws nothing',
+		'' === $wc_edm_threw,
+		$wc_edm_threw
+	);
+	wc_edm_ok(
+		'and what it emits is a style element carrying the glyph',
+		false !== strpos( $wc_edm_style, '<style>' )
+			&& false !== strpos( $wc_edm_style, '</style>' )
+			&& false !== strpos( $wc_edm_style, '\\221E' ),
+		'emitted: ' . substr( $wc_edm_style, 0, 120 )
+	);
+} else {
+	echo "::warning::wpmgr_menu_glyph_style() is not defined, so the glyph style was not exercised.\n";
+}
+
 // The frozen hash of includes/shared-menu.php is asserted in ci/static.sh
 // against WPMGR_MENU_SHA in ci/plugin.conf, and deliberately NOT repeated
 // here: two copies of the same constant drift, and the one that drifts is the
diff --git a/woocommerce-email-discount-manager.php b/woocommerce-email-discount-manager.php
index 9b2a471..f240c02 100644
--- a/woocommerce-email-discount-manager.php
+++ b/woocommerce-email-discount-manager.php
@@ -4,7 +4,7 @@
  * Plugin URI:  https://gitea.nolimit.dk/kw/woo-discount-manager
  * Update URI:  https://gitea.nolimit.dk/kw/nolimit-discounts-dist
  * Description: Apply discounts and show/hide shipping methods based on the customer's email address (full address, domain or partial match).
- * Version:     1.5.2
+ * Version:     1.5.3
  * Author:      Kristian Wind
  * Author URI:  https://gitea.nolimit.dk/kw
  * License:     GPL-2.0-or-later
@@ -28,7 +28,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 	exit;
 }
 
-define( 'WC_EDM_VERSION', '1.5.2' );
+define( 'WC_EDM_VERSION', '1.5.3' );
 define( 'WC_EDM_PLUGIN_FILE', __FILE__ );
 define( 'WC_EDM_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
 define( 'WC_EDM_PLUGIN_URL', plugin_dir_url( __FILE__ ) );