diff --git a/css/_base.scss b/css/_base.scss
index 773d533b3..0cc035f11 100644
--- a/css/_base.scss
+++ b/css/_base.scss
@@ -80,8 +80,8 @@ form {
     display: block;
     position: absolute;
     top: 15;
-    width: 186px;
-    height: 74px;
+    width: $watermarkWidth;
+    height: $watermarkHeight;
     background-size: contain;
     background-repeat: no-repeat;
     z-index: $zindex2;
diff --git a/css/_variables.scss b/css/_variables.scss
index 76cbb8a6d..8a3c6359b 100644
--- a/css/_variables.scss
+++ b/css/_variables.scss
@@ -145,3 +145,9 @@ $unsupportedBrowserTitleColor: #fff;
 $unsupportedBrowserTitleFontSize: 24px;
 $unsupportedDesktopBrowserTextColor: rgba(255, 255, 255, 0.7);
 $unsupportedDesktopBrowserTextFontSize: 21px;
+
+/**
+ * The size of the default watermark.
+ */
+$watermarkWidth: 186px;
+$watermarkHeight: 74px;
\ No newline at end of file