diff --git a/src/ui.js b/src/ui.js
index 183eeaf..9c23d64 100644
--- a/src/ui.js
+++ b/src/ui.js
@@ -65,6 +65,16 @@ function fmtDate(d) {
   return d.toLocaleDateString('en-US', { weekday: 'short', day: '2-digit', month: 'short', year: 'numeric' });
 }
 
+function esc(s) {
+  if (s == null) return '';
+  return String(s)
+    .replace(/&/g, '&')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#39;');
+}
+
 export class Dialog {
   constructor({ onTargetChange, onModeChange, onPosChange, onClose } = {}) {
     this.onTargetChange = onTargetChange;
@@ -74,7 +84,6 @@ export class Dialog {
     this.root = null;
     this.dragState = null;
     this.mode = 'free';
-    this.warn = null;
   }
 
   mount({ initialMode = 'free', initialPos = { x: 0, y: 0 } } = {}) {
@@ -136,31 +145,34 @@ export class Dialog {
   }
 
   _wireHeaderDrag() {
-    const onDown = (e) => {
-      if (this.mode !== 'free') return;
+    const self = this;
+    this.root.addEventListener('mousedown', (e) => {
+      if (self.mode !== 'free') return;
       if (e.target.classList.contains('tat-close')) return;
-      const rect = this.root.getBoundingClientRect();
-      this.dragState = { dx: e.clientX - rect.left, dy: e.clientY - rect.top };
+      const rect = self.root.getBoundingClientRect();
+      self.dragState = { dx: e.clientX - rect.left, dy: e.clientY - rect.top };
       e.preventDefault();
-    };
-    const onMove = (e) => {
-      if (!this.dragState) return;
-      const x = e.clientX - this.dragState.dx;
-      const y = e.clientY - this.dragState.dy;
-      this.root.style.left = `${x}px`;
-      this.root.style.top = `${y}px`;
-      this.root.style.right = 'auto';
-      this.root.style.bottom = 'auto';
-    };
-    const onUp = () => {
-      if (!this.dragState) return;
-      const rect = this.root.getBoundingClientRect();
-      this.dragState = null;
-      this.onPosChange && this.onPosChange({ x: rect.left, y: rect.top });
-    };
-    this.root.addEventListener('mousedown', onDown);
-    document.addEventListener('mousemove', onMove);
-    document.addEventListener('mouseup', onUp);
+
+      const onMove = (ev) => {
+        if (!self.dragState) return;
+        const x = ev.clientX - self.dragState.dx;
+        const y = ev.clientY - self.dragState.dy;
+        self.root.style.left = x + 'px';
+        self.root.style.top = y + 'px';
+        self.root.style.right = 'auto';
+        self.root.style.bottom = 'auto';
+      };
+      const onUp = () => {
+        if (!self.dragState) return;
+        const r = self.root.getBoundingClientRect();
+        self.dragState = null;
+        self.onPosChange && self.onPosChange({ x: r.left, y: r.top });
+        document.removeEventListener('mousemove', onMove);
+        document.removeEventListener('mouseup', onUp);
+      };
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    });
   }
 
   render(state) {
@@ -169,7 +181,7 @@ export class Dialog {
     if (error) {
       this.root.innerHTML = `
         <div class="tat-header"><strong>⚙ Attribute Tracker</strong><span class="tat-close">✕</span></div>
-        <div class="tat-error">${error}<button data-action="reload">Reload</button></div>
+        <div class="tat-error">${esc(error)}<button data-action="reload">Reload</button></div>
       `;
       this.root.querySelector('[data-action="reload"]').onclick = () => location.reload();
       this.root.querySelector('.tat-close').onclick = () => this.onClose && this.onClose();
@@ -192,7 +204,7 @@ export class Dialog {
         <strong>⚙ Attribute Tracker</strong>
         <span class="tat-close" title="Hide for this session">✕</span>
       </div>
-      <div class="tat-row"><span>Attribute</span><span><strong>${attr || '—'}</strong> · <em>${gym || '—'}</em></span></div>
+      <div class="tat-row"><span>Attribute</span><span><strong>${esc(attr)}</strong> · <em>${esc(gym)}</em></span></div>
       <div class="tat-row"><span>Current</span><span>${fmtFull(current)}</span></div>
       <div class="tat-row tat-target">
         <span>Target</span>
@@ -211,7 +223,7 @@ export class Dialog {
       <div class="tat-row"><span>Trains to go</span><span>≈ ${fmtFull(est.trainsToGo)}</span></div>
       <div class="tat-row"><span>ETA</span><span>${est.days > 0 ? `~ ${fmtFull(est.days)} days (${fmtDate(est.eta)})` : '—'}</span></div>
       <div class="tat-modes">${modes}</div>
-      ${warn ? `<div class="tat-warn">⚠ ${warn}</div>` : ''}
+      ${warn ? `<div class="tat-warn">⚠ ${esc(warn)}</div>` : ''}
     `;
 
     this.root.querySelector('.tat-close').onclick = () => this.onClose && this.onClose();