Index: gc_lang/fr/webext/content_scripts/panel.css
==================================================================
--- gc_lang/fr/webext/content_scripts/panel.css
+++ gc_lang/fr/webext/content_scripts/panel.css
@@ -5,17 +5,19 @@
 
 .grammalecte_panel {
     padding: 0;
     margin: 0;
     position: fixed;
-    z-index: 100;
+    box-sizing: content-box;
+    z-index: 2147483640; /* maximum is 2147483647: https://stackoverflow.com/questions/491052/minimum-and-maximum-value-of-z-index */
     border: 2px solid hsl(210, 0%, 50%);
     border-radius: 10px 10px 10px 10px;
     background-color: hsl(210, 20%, 100%);
     color: hsl(210, 10%, 4%);
     font-family: "Trebuchet MS", "Liberation Sans", sans-serif;
     box-shadow: 0 0 4px 2px hsl(210, 0%, 50%);
+    line-height: normal;
 }
 
 .grammalecte_panel_bar {
     position: sticky;
     width: 100%;