Get rid of grey background when content doesn't fill the screen

docsite/_themes/srtd/static/css/theme.css

@@ -2971,7 +2971,7 @@ li.wy-form-gallery-edit .arrow {
     float: left;
     margin-right: 2.35765%;
     width: 100%;
-    background: #fcfcfc;
+    background: #fff;
     padding: 1.618em;
     margin-right: 0;
 }
@@ -2987,7 +2987,7 @@ li.wy-form-gallery-edit .arrow {
     margin-right: auto;
     max-width: 460px;
     margin-top: 1.618em;
-    background: #fcfcfc;
+    background: #fff;
     padding: 1.618em;
 }
 
@@ -4000,7 +4000,7 @@ pre.literal-block {
 }
 
 .wy-body-for-nav {
-    background: left repeat-y #fcfcfc;
+    background: left repeat-y #fff;
     background-image: url(data:image/png;
     base64, iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAyRpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADw/eHBhY2tldCBiZWdpbj0i77u/IiBpZD0iVzVNME1wQ2VoaUh6cmVTek5UY3prYzlkIj8+IDx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IkFkb2JlIFhNUCBDb3JlIDUuMy1jMDExIDY2LjE0NTY2MSwgMjAxMi8wMi8wNi0xNDo1NjoyNyAgICAgICAgIj4gPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4gPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIgeG1sbnM6eG1wPSJodHRwOi8vbnMuYWRvYmUuY29tL3hhcC8xLjAvIiB4bWxuczp4bXBNTT0iaHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wL21tLyIgeG1sbnM6c3RSZWY9Imh0dHA6Ly9ucy5hZG9iZS5jb20veGFwLzEuMC9zVHlwZS9SZXNvdXJjZVJlZiMiIHhtcDpDcmVhdG9yVG9vbD0iQWRvYmUgUGhvdG9zaG9wIENTNiAoTWFjaW50b3NoKSIgeG1wTU06SW5zdGFuY2VJRD0ieG1wLmlpZDoxOERBMTRGRDBFMUUxMUUzODUwMkJCOThDMEVFNURFMCIgeG1wTU06RG9jdW1lbnRJRD0ieG1wLmRpZDoxOERBMTRGRTBFMUUxMUUzODUwMkJCOThDMEVFNURFMCI+IDx4bXBNTTpEZXJpdmVkRnJvbSBzdFJlZjppbnN0YW5jZUlEPSJ4bXAuaWlkOjE4REExNEZCMEUxRTExRTM4NTAyQkI5OEMwRUU1REUwIiBzdFJlZjpkb2N1bWVudElEPSJ4bXAuZGlkOjE4REExNEZDMEUxRTExRTM4NTAyQkI5OEMwRUU1REUwIi8+IDwvcmRmOkRlc2NyaXB0aW9uPiA8L3JkZjpSREY+IDwveDp4bXBtZXRhPiA8P3hwYWNrZXQgZW5kPSJyIj8+EwrlwAAAAA5JREFUeNpiMDU0BAgwAAE2AJgB9BnaAAAAAElFTkSuQmCC);
     background-size: 300px 1px;
@@ -4066,7 +4066,7 @@ pre.literal-block {
 
 .wy-nav-content-wrap {
     margin-left: 300px;
-    background: #fcfcfc;
+    background: #fff;
     min-height: 100%;
 }
 
@@ -4135,7 +4135,7 @@ footer p {
 
 @media screen and (max-width: 768px) {
     .wy-body-for-nav {
-        background: #fcfcfc;
+        background: #fff;
     }
 
     .wy-nav-top {
@@ -4171,12 +4171,12 @@ footer p {
 
 @media screen and (min-width: 1400px) {
     .wy-nav-content-wrap {
-        background: rgba(0, 0, 0, 0.05);
+        background: #fff;
     }
 
     .wy-nav-content {
         margin: 0;
-        background: #fcfcfc;
+        background: #fff;
     }
 }