diff --git a/doc/stylesheet.css b/doc/stylesheet.css
index 7e827eeba7..20b8bc329d 100644
--- a/doc/stylesheet.css
+++ b/doc/stylesheet.css
@@ -1,33 +1,33 @@
 /* The standard CSS for doxygen 1.8.6 */
 
 body, table, div, p, dl {
-	font: 400 14px/22px Helvetica, 'Segoe UI', Arial, freesans, sans-serif;
-	word-wrap: break-word;
+    font: 400 14px/22px Helvetica, 'Segoe UI', Arial, freesans, sans-serif;
+    word-wrap: break-word;
 }
 
 code {
-	font: 12px Consolas, "Liberation Mono", Courier, monospace;
-	font-size: 85%;
-	white-space: pre-wrap;
-	padding: 1px 5px;
-	padding: 0;
-	background-color: #ddd;
-	vertical-align: baseline;
+    font: 12px Consolas, "Liberation Mono", Courier, monospace;
+    font-size: 85%;
+    white-space: pre-wrap;
+    padding: 1px 5px;
+    padding: 0;
+    background-color: #ddd;
+    vertical-align: baseline;
 }
 
 body {
-	background-image: url(bodybg.png);
-	margin: 0 auto;
+    background-image: url(bodybg.png);
+    margin: 0 auto;
 }
 
 div.contents {
-	width: 980px;
-	margin: 0 auto;
-	padding: 15px 15px;
-	border: 1px solid rgb(10, 80, 122);
-	background-color: #fff;
+    width: 980px;
+    margin: 0 auto;
+    padding: 15px 15px;
+    border: 1px solid rgb(10, 80, 122);
+    background-color: #fff;
 }
 
 span.arrow {
-	height: 13px;
+    height: 13px;
 }