diff --git a/manifest.json b/manifest.json
index 047f699..b1232e0 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,7 +1,7 @@
 {
 	"id": "hexmaker",
 	"name": "Hexmap World Creator",
-	"version": "1.2.2",
+	"version": "1.2.3",
 	"minAppVersion": "1.12.0",
 	"description": "Create a hex map and a guidebook level wiki for your setting with minimal fuss. Hex crawl worldbuilding toolbox. System agnostic, ready for any TRPG you care to run in it.",
 	"author": "morkdev",
diff --git a/package-lock.json b/package-lock.json
index f4679d3..a8fb124 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "hexmaker-plugin",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "hexmaker-plugin",
-      "version": "1.2.2",
+      "version": "1.2.3",
       "license": "MIT",
       "dependencies": {
         "minisearch": "^7.2.0"
diff --git a/package.json b/package.json
index 5d9c0e7..8740c9b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hexmaker-plugin",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "description": "A plugin to power hex crawl worldbuilding and running.",
   "main": "main.js",
   "scripts": {
diff --git a/src/HexmakerModal.ts b/src/HexmakerModal.ts
index ca02a58..30ae3c8 100644
--- a/src/HexmakerModal.ts
+++ b/src/HexmakerModal.ts
@@ -12,13 +12,30 @@ export class HexmakerModal extends Modal {
 		if (modalEl.dataset.draggable) return;
 		modalEl.dataset.draggable = "1";
 		modalEl.addClass("duckmage-editor-modal-drag");
-		modalEl.setCssProps({
-			position: 'absolute',
-			left: '50%',
-			top: '50%',
-			transform: 'translate(-50%, -50%)',
-			margin: '0',
-		});
+
+		// position: fixed so the containing block is the viewport rather than
+		// the nearest transform/filter/will-change ancestor. Other plugins or
+		// themes can establish a containing block on a `.modal-container` ancestor
+		// (issue #26 — a third-party plugin re-rooted position:absolute away from
+		// the viewport, landing the modal partway off-screen).
+		modalEl.setCssProps({ position: 'fixed', margin: '0' });
+
+		const doc = modalEl.ownerDocument;
+		const win = doc.defaultView ?? window;
+
+		// Clamp the centered position so the modal can never open off-screen,
+		// even if a transformed ancestor still establishes a containing block
+		// for fixed positioning.
+		const PADDING = 8;
+		const centerInViewport = () => {
+			const r = modalEl.getBoundingClientRect();
+			const maxLeft = Math.max(PADDING, win.innerWidth - r.width - PADDING);
+			const maxTop = Math.max(PADDING, win.innerHeight - r.height - PADDING);
+			const left = Math.min(Math.max((win.innerWidth - r.width) / 2, PADDING), maxLeft);
+			const top = Math.min(Math.max((win.innerHeight - r.height) / 2, PADDING), maxTop);
+			modalEl.setCssProps({ left: `${left}px`, top: `${top}px` });
+		};
+		win.requestAnimationFrame(centerInViewport);
 
 		modalEl.addEventListener("mousedown", (e: MouseEvent) => {
 			const modalContent = modalEl.querySelector<HTMLElement>(".modal-content");
@@ -27,18 +44,18 @@ export class HexmakerModal extends Modal {
 
 			e.preventDefault();
 			const r = modalEl.getBoundingClientRect();
-			modalEl.setCssProps({ transform: 'none', left: `${r.left}px`, top: `${r.top}px` });
+			modalEl.setCssProps({ left: `${r.left}px`, top: `${r.top}px` });
 			const sx = e.clientX, sy = e.clientY;
 			const ox = r.left, oy = r.top;
 			const onMove = (ev: MouseEvent) => {
 				modalEl.setCssProps({ left: `${ox + ev.clientX - sx}px`, top: `${oy + ev.clientY - sy}px` });
 			};
 			const onUp = () => {
-				activeDocument.removeEventListener("mousemove", onMove);
-				activeDocument.removeEventListener("mouseup", onUp);
+				doc.removeEventListener("mousemove", onMove);
+				doc.removeEventListener("mouseup", onUp);
 			};
-			activeDocument.addEventListener("mousemove", onMove);
-			activeDocument.addEventListener("mouseup", onUp);
+			doc.addEventListener("mousemove", onMove);
+			doc.addEventListener("mouseup", onUp);
 		});
 	}
 }
diff --git a/versions.json b/versions.json
index 7474ff4..12c0fd2 100644
--- a/versions.json
+++ b/versions.json
@@ -37,5 +37,6 @@
 	"1.1.15": "1.12.0",
 	"1.2.0": "1.12.0",
 	"1.2.1": "1.12.0",
-	"1.2.2": "1.12.0"
+	"1.2.2": "1.12.0",
+	"1.2.3": "1.12.0"
 }
\ No newline at end of file