Index: gc_lang/fr/webext/content_scripts/menu.css
==================================================================
--- gc_lang/fr/webext/content_scripts/menu.css
+++ gc_lang/fr/webext/content_scripts/menu.css
@@ -22,11 +22,11 @@
     margin-left: -10px;
     border-radius: 5px;
     border: 3px solid hsl(210, 50%, 30%);
     box-shadow: 0px 0px 2px hsla(210, 10%, 10%, .5);
     background-color: hsl(210, 50%, 30%);
-    font-family: "Trebuchet MS", "Liberation Sans", sans-serif;
+    font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
 }
 
 .grammalecte_menu_item {
     padding: 3px 10px;
     background-color: hsl(210, 50%, 40%);
@@ -66,16 +66,16 @@
 .grammalecte_menu_header {
     padding: 2px 10px;
     background-color: hsl(210, 50%, 30%);
     background-image:  url('data:image/png;base64,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');
     background-repeat: no-repeat;
-    background-position: 20% 50%;
+    background-position: 10% 50%;
     font-size: 16px;
-    font-family: 'Yanone Kaffeesatz', "Liberation Sans Narrow", sans-serif;
+    font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
     color: hsl(210, 50%, 90%);
     text-shadow: 0px 0px 2px hsla(210, 10%, 10%, .9);
     text-align: center;
 }
 .grammalecte_menu_footer {
     padding: 2px 10px;
     background-color: hsl(210, 50%, 30%);
 }

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
@@ -11,11 +11,11 @@
     z-index: 2147483640; /* maximum is 2147483647: https://stackoverflow.com/questions/491052/minimum-and-maximum-value-of-z-index */
     border: 2px solid hsl(210, 10%, 50%);
     border-radius: 10px 10px 10px 10px;
     background-color: hsl(210, 0%, 100%);
     color: hsl(0, 0%, 0%);
-    font-family: "Trebuchet MS", "Liberation Sans", sans-serif;
+    font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
     box-shadow: 0 0 2px 1px hsla(210, 50%, 50%, .5);
     line-height: normal;
     text-shadow: none;
     text-decoration: none;
 }

Index: gc_lang/fr/webext/panel/main.css
==================================================================
--- gc_lang/fr/webext/panel/main.css
+++ gc_lang/fr/webext/panel/main.css
@@ -68,11 +68,11 @@
 
 html {
     box-sizing: border-box;
     width: 400px;
     height: 500px;
-    font-family: "Trebuchet MS", "Liberation Sans", sans-serif;
+    font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
 }
 body {
     width: 400px;
     height: 500px;
 }
@@ -187,11 +187,11 @@
 }
 .opt_subsection h2 {
     color: hsl(210, 30%, 50%);
     margin-bottom: 3px;
     font-size: 16px;
-    font-family: "Trebuchet MS", sans-serif;
+    font-family: "Trebuchet MS", "Fira Sans", "Liberation Sans", sans-serif;
 }
 .opt_subsection p {
     padding: 2px 3px;
     display: flex;
     align-items: center;