Fixes #3316 - Make Live TV Guide scrollbar visible.

Copied some missing elements from dark theme.css and made a couple tweaks. Not sure if everyone will love the look. But the scrollbar is now visible.

src/themes/light/theme.css

@@ -1,3 +1,8 @@
+* {
+    scrollbar-width: thin;
+    scrollbar-color: #999 #303030;
+}
+
 .skinHeader,
 html {
     color: #222;
@@ -465,6 +470,29 @@ html {
     border-color: #00a4dc !important;
 }
 
+::-webkit-scrollbar-track {
+    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
+    box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
+}
+
+
+.layout-desktop ::-webkit-scrollbar,
+.layout-tv ::-webkit-scrollbar {
+    width: 0.4em;
+    height: 0.4em;
+}
+
+::-webkit-scrollbar-thumb:horizontal,
+::-webkit-scrollbar-thumb:vertical {
+    border-radius: 2px;
+    -webkit-border-radius: 2px;
+    background: center no-repeat #999;
+}
+
+.timeslotHeaders-desktop::-webkit-scrollbar {
+    height: 0.7em;
+}
+
 .metadataSidebarIcon {
     color: #00a4dc;
 }