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
@@ -32,11 +32,11 @@
         this.center();
     }
 
     _createPanel (sTitle) {
         try {
-            let xPanel = oGrammalecte.createNode("div", {id: this.sId, className: "grammalecte_panel"});
+            let xPanel = oGrammalecte.createNode("div", {id: this.sId, className: "grammalecte_panel" });
             this.xPanelBar.appendChild(oGrammalecte.createNode("div", {className: "grammalecte_panel_invisible_marker", textContent: "__grammalecte_panel__"}));
             this.xPanelBar.appendChild(this._createButtons());
             let xTitle = oGrammalecte.createNode("div", {className: "grammalecte_panel_title"});
             xTitle.appendChild(this._createLogo());
             xTitle.appendChild(oGrammalecte.createNode("div", {className: "grammalecte_panel_label", textContent: sTitle}));
@@ -124,33 +124,49 @@
         oGrammalecte.clearRightClickedNode();
     }
 
     center () {
         let nHeight = (this.bFlexible) ? window.innerHeight-100 : this.nHeight;
-        this.xPanel.style = `top: 50%; left: 50%; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px; margin-left: -${this.nWidth/2}px;`;
+        //this.xPanel.style = `top: 50%; left: 50%; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px; margin-left: -${this.nWidth/2}px;`;
+        this.setSizeAndPosition(`${this.nWidth}px`, `${nHeight}px`, "50%", "", "", "50%", `-${nHeight/2}px`, `-${this.nWidth/2}px`);
     }
 
     stickToLeft () {
         let nHeight = (this.bFlexible) ? window.innerHeight-100 : this.nHeight;
-        this.xPanel.style = `top: 50%; left: -2px; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px;`;
+        //this.xPanel.style = `top: 50%; left: -2px; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px;`;
+        this.setSizeAndPosition(`${this.nWidth}px`, `${nHeight}px`, "50%", "", "", "-2px", `-${nHeight/2}px`, "");
     }
 
     stickToRight () {
         let nHeight = (this.bFlexible) ? window.innerHeight-100 : this.nHeight;
-        this.xPanel.style = `top: 50%; right: -2px; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px;`;
+        //this.xPanel.style = `top: 50%; right: -2px; width: ${this.nWidth}px; height: ${nHeight}px; margin-top: -${nHeight/2}px;`;
+        this.setSizeAndPosition(`${this.nWidth}px`, `${nHeight}px`, "50%", "-2px", "", "", `-${nHeight/2}px`, "");
     }
 
     stickToTop () {
         let nWidth = (this.bFlexible) ? Math.floor(window.innerWidth/2) : this.nWidth;
         let nHeight = (this.bFlexible) ? Math.floor(window.innerHeight*0.45) : this.nHeight;
-        this.xPanel.style = `top: -2px; left: 50%; width: ${nWidth}px; height: ${nHeight}px; margin-left: -${nWidth/2}px;`;
+        //this.xPanel.style = `top: -2px; left: 50%; width: ${nWidth}px; height: ${nHeight}px; margin-left: -${nWidth/2}px;`;
+        this.setSizeAndPosition(`${nWidth}px`, `${nHeight}px`, "-2px", "", "", "50%", "", `-${nWidth/2}px`);
     }
 
     stickToBottom () {
         let nWidth = (this.bFlexible) ? Math.floor(window.innerWidth/2) : this.nWidth;
         let nHeight = (this.bFlexible) ? Math.floor(window.innerHeight*0.45) : this.nHeight;
-        this.xPanel.style = `bottom: -2px; left: 50%; width: ${nWidth}px; height: ${nHeight}px; margin-left: -${nWidth/2}px;`;
+        //this.xPanel.style = `bottom: -2px; left: 50%; width: ${nWidth}px; height: ${nHeight}px; margin-left: -${nWidth/2}px;`;
+        this.setSizeAndPosition(`${nWidth}px`, `${nHeight}px`, "", "", "-2px", "50%", "", `-${nWidth/2}px`);
+    }
+
+    setSizeAndPosition (sWidth, sHeight, sTop, sRight, sBottom, sLeft, sMarginTop, sMarginLeft) {
+        this.xPanel.style.width = sWidth;
+        this.xPanel.style.height = sHeight;
+        this.xPanel.style.top = sTop;
+        this.xPanel.style.right = sRight;
+        this.xPanel.style.bottom = sBottom;
+        this.xPanel.style.left = sLeft;
+        this.xPanel.style.marginTop = sMarginTop;
+        this.xPanel.style.marginLeft = sMarginLeft;
     }
 
     reduce () {
         // todo
     }

Index: gc_lang/fr/webext/content_scripts/panel_tf.js
==================================================================
--- gc_lang/fr/webext/content_scripts/panel_tf.js
+++ gc_lang/fr/webext/content_scripts/panel_tf.js
@@ -13,10 +13,11 @@
     constructor (...args) {
         super(...args);
         this.xTFNode = this._createTextFormatter();
         this.xPanelContent.appendChild(this.xTFNode);
         this.xTextArea = null;
+        this.xPanel.style.zIndex = 2147483647; /* maximum is 2147483647: https://stackoverflow.com/questions/491052/minimum-and-maximum-value-of-z-index */
 
         this.TextFormatter = new TextFormatter();
         this.formatText = this.TextFormatter.formatTextRuleCount;
         this.removeHyphenAtEndOfParagraphs = this.TextFormatter.removeHyphenAtEndOfParagraphsCount;
         this.mergeContiguousParagraphs = this.TextFormatter.mergeContiguousParagraphsCount;