diff --git a/docs/cmms-bridge.js b/docs/cmms-bridge.js
index a527bfe..e569c5c 100644
--- a/docs/cmms-bridge.js
+++ b/docs/cmms-bridge.js
@@ -350,10 +350,45 @@
 		trace('ensureBoard: created a starter board');
 	}
 
+	// Working-data stores restoreDevice() / processImportData() write into. The
+	// KiCad symbol-library stores (kicadSymbols, symbolTypes, componentTypes*,
+	// pinDirections) are reference data and expensive to rebuild — leave them.
+	const CMMS_PROJECT_STORES = ['devices', 'boards', 'components', 'images',
+		'overlappedImages', 'nets', 'schemas', 'schemaComponents'];
+
+	// The .pcbretrace.zip attachment is the single source of truth for a CMMS
+	// board — there is no local working copy to preserve between sessions. Clear
+	// the project stores before importing so restoreDevice() starts from empty
+	// and can't accrete duplicate image / net rows across repeated opens in the
+	// same browser (its merge path only de-dupes when timestamps say the import
+	// is newer, and CMMS-created boards carry no lastModified).
+	async function wipeProjectData() {
+		if (!db || !db.db) return;
+		const stores = CMMS_PROJECT_STORES.filter(s => db.db.objectStoreNames.contains(s));
+		if (stores.length) {
+			await new Promise((res, rej) => {
+				const tx = db.db.transaction(stores, 'readwrite');
+				stores.forEach(s => tx.objectStore(s).clear());
+				tx.oncomplete = () => res();
+				tx.onerror = () => rej(tx.error);
+				tx.onabort = () => rej(tx.error || new Error('wipe aborted'));
+			});
+		}
+		// studio.js caches these in shared globals — reset so a fresh import (or
+		// ensureBoard) doesn't reuse a now-deleted device/board.
+		deviceList = []; bomList = []; bomData = []; bomImages = [];
+		currentDeviceId = null; currentBomId = null; currentImgId = null;
+		trace('wipeProjectData: cleared', stores.join(', ') || '(none)');
+	}
+
 	async function init() {
-		if (CFG.dark) document.documentElement.setAttribute('data-theme', 'dark');
+		// Set light explicitly too (not just dark) so studio.js can tell a CMMS
+		// embed from standalone use and pass the theme to the schema.html iframe.
+		document.documentElement.setAttribute('data-theme', CFG.dark ? 'dark' : 'light');
 		injectControls();
 
+		try { await wipeProjectData(); } catch (e) { trace('wipeProjectData threw:', e && e.message); }
+
 		if (CFG.loadUrl) {
 			status('Loading board…');
 			try {
diff --git a/docs/cmms-schema-light.css b/docs/cmms-schema-light.css
new file mode 100644
index 0000000..09e1ee4
--- /dev/null
+++ b/docs/cmms-schema-light.css
@@ -0,0 +1,40 @@
+/*
+ * CMMS light theme for pcb-retrace schema.html (the "Schema ReTrace" iframe).
+ *
+ * NOT part of the fork. schema.html is dark-only upstream, which clashes when
+ * the CMMS is in light mode. studio.js appends ?theme=light|dark to the iframe
+ * src (from the CMMS-set data-theme on the parent document); an inline script
+ * in schema.html mirrors it onto <html data-theme>. Every rule here is gated on
+ * [data-theme="light"] so standalone use and CMMS dark mode are untouched.
+ *
+ * The schematic canvas (#sch-canvas, painted by schema/draw.js with hardcoded
+ * colours) deliberately stays dark — it reads as a drawing surface, like an EDA
+ * canvas, not UI chrome. Only the surrounding panels/header/modals are themed.
+ */
+:root[data-theme="light"] {
+	--bg: #ffffff;
+	--surface: #f6f8fa;
+	--surface2: #eaeef2;
+	--border: #d0d7de;
+	--accent: #0a7d5f;
+	--accent2: #0969da;
+	--accent3: #cf400b;
+	--warn: #9a6700;
+	--text: #1f2328;
+	--text2: #656d76;
+}
+
+/* Canvas overlays hardcode the dark page bg — flip to a light scrim. */
+[data-theme="light"] #coord-readout,
+[data-theme="light"] #zoom-ind { background: rgba(255,255,255,.82); }
+[data-theme="light"] #hint-bar { background: rgba(255,255,255,.9); color: var(--text2); }
+
+/* Mobile drawer / toolbar shadows are tuned for a dark bg. */
+[data-theme="light"] #left-panel { box-shadow: 4px 0 15px rgba(140,149,159,.35); }
+[data-theme="light"] #right-panel { box-shadow: -4px 0 15px rgba(140,149,159,.35); }
+[data-theme="light"] #canvas-toolbar .btn { box-shadow: 0 2px 8px rgba(140,149,159,.35); }
+
+/* Selection tints read as near-invisible on white — lift them slightly. */
+[data-theme="light"] .net-item.selected,
+[data-theme="light"] .db-item.selected { background: rgba(10,125,95,.12); }
+[data-theme="light"] .comp-item.selected { background: rgba(9,105,218,.12); }
diff --git a/docs/schema.html b/docs/schema.html
index c5906fb..2a70a08 100644
--- a/docs/schema.html
+++ b/docs/schema.html
@@ -9,6 +9,10 @@
 <head>
 <!-- CMMS fork: Google Tag / analytics removed (no external requests) -->
 <meta charset="UTF-8">
+<!-- CMMS fork: mirror the parent's ?theme= onto <html> before paint and, for
+     light, pull in the CMMS override sheet. Fully no-op standalone (no ?theme=),
+     so vanilla schema.html keeps its dark-only look with no dangling asset. -->
+<script>try{var t=new URLSearchParams(location.search).get('theme');if(t==='light'||t==='dark'){document.documentElement.setAttribute('data-theme',t);if(t==='light'){var l=document.createElement('link');l.rel='stylesheet';l.href='cmms-schema-light.css';document.head.appendChild(l);}}}catch(e){}</script>
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>Schematic ReTrace</title>
 <script src="vendor/zip.min.js"></script>
diff --git a/docs/studio.js b/docs/studio.js
index 0198839..1ec2310 100644
--- a/docs/studio.js
+++ b/docs/studio.js
@@ -1528,7 +1528,10 @@ function switchView(v) {
 				//	'contentWindow.location:', frame.contentWindow?.location?.href);
 				frame.contentWindow.postMessage(msg, '*');
 			};
-			frame.src = 'schema.html';
+			// CMMS fork: hand the schema iframe the active theme so its
+			// light-mode override sheet can match the CMMS (no-op standalone).
+			const _t = document.documentElement.getAttribute('data-theme');
+			frame.src = 'schema.html' + (_t ? '?theme=' + encodeURIComponent(_t) : '');
 			// console.log('[studio] frame clientWidth:', frame.clientWidth,
 			//	'clientHeight:', frame.clientHeight,
 			//	'offsetWidth:', frame.offsetWidth,