Index: gc_lang/fr/webext/content_scripts/panel.js
==================================================================
--- gc_lang/fr/webext/content_scripts/panel.js
+++ gc_lang/fr/webext/content_scripts/panel.js
@@ -128,10 +128,14 @@
 
     adjustHeight () {
         this.xPanelContent.style.height = this.xPanelContent.firstChild.offsetHeight + "px"; // xPanelContent has only one child
         this.xPanel.style.height = this.xPanelBar.offsetHeight + this.xPanelContent.offsetHeight + 10 + "px";
     }
+
+    getWidth () {
+        return this.xPanelContent.offsetWidth;
+    }
 
     logInnerHTML () {
         // for debugging
         console.log(this.xPanel.innerHTML);
     }

Index: gc_lang/fr/webext/content_scripts/panel_gc.js
==================================================================
--- gc_lang/fr/webext/content_scripts/panel_gc.js
+++ gc_lang/fr/webext/content_scripts/panel_gc.js
@@ -306,11 +306,11 @@
 
     show (sNodeErrorId) {  // err
         try {
             let xNodeErr = document.getElementById(sNodeErrorId);
             this.sErrorId = xNodeErr.dataset.error_id; // we store error_id here to know if spell_suggestions are given to the right word.
-            let nLimit = 500 - 330; // paragraph width - tooltip width
+            let nLimit = oGrammalecte.oGCPanel.getWidth() - 330; // paragraph width - tooltip width
             this.xTooltipArrow.style.top = (xNodeErr.offsetTop + 16) + "px";
             this.xTooltipArrow.style.left = (xNodeErr.offsetLeft + Math.floor((xNodeErr.offsetWidth / 2))-4) + "px"; // 4 is half the width of the arrow.
             this.xTooltip.style.top = (xNodeErr.offsetTop + 20) + "px";
             this.xTooltip.style.left = (xNodeErr.offsetLeft > nLimit) ? nLimit + "px" : xNodeErr.offsetLeft + "px";
             if (xNodeErr.dataset.error_type === "grammar") {