diff -r 000000000000 -r 6474c204b198 browser/themes/windows/devtools/font-inspector.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/themes/windows/devtools/font-inspector.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,78 @@
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  padding-bottom: 20px;
+}
+
+#all-fonts {
+  padding: 0;
+  margin: 0;
+}
+
+#showall {
+  border-radius: 0;
+  border: 1px solid black;
+  margin: 3px;
+  cursor: pointer;
+  position: fixed;
+  bottom: 0;
+  right: 0;
+}
+
+.font {
+  padding: 10px 10px;
+}
+
+.theme-dark .font {
+  border-bottom: 1px solid #444;
+}
+
+.theme-light .font {
+  border-bottom: 1px solid #DDD;
+}
+
+.font:last-of-type {
+  border-bottom: 0;
+}
+
+.theme-light .font:nth-child(even) {
+  background: #F4F4F4;
+}
+
+.font-preview {
+  height: 60px;
+  width: 100%;
+  border: 0;
+  display: block;
+}
+
+.font-info {
+  display: block;
+}
+
+.font-name {
+  display: inline;
+}
+
+.font-css-code {
+  max-width: 100%;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  padding: 5px;
+}
+
+.theme-light .font-css-code,
+.theme-light .font-url {
+  border: 1px solid #CCC;
+  background: white;
+}
+
+.theme-dark .font-css-code,
+.theme-dark .font-url {
+  border: 1px solid #333;
+  background: black;
+  color: white;
+}