better menu on mobile

theme/static/css/main.css

@@ -157,7 +157,7 @@ body > header img {
 	width: 100%;
 	height: 100%;
 	display: none;
-	background-color: rgba(120,120, 120, 0.5);
+	background-color: rgba(120,120, 120, 0.7);
 	-webkit-user-select: none; /* Safari */
 	-moz-user-select: none; /* Firefox */
 	-ms-user-select: none; /* IE10+/Edge */
@@ -190,6 +190,8 @@ body > header img {
 	}
 	#sitemenu-container nav > ul {
 		flex-direction: column;
+		max-height: calc(100vh - 3.2rem);
+		overflow: scroll;
 	}
 	#sitemenu-container nav > ul > li {
 		width: 100%;