homepage png - ratio 2

docs/_static/css/custom.css

@@ -176,7 +176,7 @@ span#overview {
 	display: none;
 }
 
-#welcome-to-the-open-source-nebulas-wiki {
+#welcome-to-the-open-source-nebulas-wiki.section {
 	background: #000 url(https://raw.githubusercontent.com/nebulasio/nebdocs/master/docs/resources/overview/bg.png) no-repeat 50% 0;
 	color: #9b9b9b;
 	max-width: 1920px;
@@ -252,7 +252,7 @@ span#overview {
 
 #use-wiki.section #get-involved.section {
     clear: left;
-    background: #f7f7f7 url(https://github.com/nebulasio/nebdocs/blob/master/docs/resources/overview/icon-contribute.png) no-repeat 100% 0;
+    background: #f7f7f7 url(https://github.com/nebulasio/nebdocs/blob/master/docs/resources/overview/icon-contribute.png?raw=ture) no-repeat 100% 0;
     padding: 2em 1.618em;
     margin: 2em -1.618em 0 -1.618em;
 }
@@ -261,7 +261,7 @@ span#overview {
 	box-shadow: none;
 }
 
-#use-wiki.section #get-involved.section a {
+#use-wiki.section #get-involved.section a.reference {
 	display: inline-block;
 	padding: 0 3rem;
 }
@@ -296,3 +296,22 @@ span#overview {
 		float: none;
 	}
 }
+
+
+
+/* ratio 2 */
+
+@media (-webkit-min-device-pixel-ratio: 2) {
+	#use-wiki.section #mainnet.section {
+		background-image: url(https://raw.githubusercontent.com/nebulasio/nebdocs/master/docs/resources/overview/icon-mainnet@2x.png);
+	}
+	#use-wiki.section #dapps.section {
+		background-image: url(https://raw.githubusercontent.com/nebulasio/nebdocs/master/docs/resources/overview/icon-dapps@2x.png);
+	}
+	#use-wiki.section #ecosystem.section {
+		background-image: url(https://raw.githubusercontent.com/nebulasio/nebdocs/master/docs/resources/overview/icon-eco@2x.png);
+	}
+	#use-wiki.section #get-involved.section {
+		background-image: url(https://raw.githubusercontent.com/nebulasio/nebdocs/master/docs/resources/overview/icon-contribute@2x.png?raw=ture);
+	}
+}