Reduce padding on mobile

Signed-off-by: Marcus Noble <github@marcusnoble.co.uk>

src/index.html

@@ -207,7 +207,7 @@
         background-size: contain
       }
       main {
-        padding: .5em 4em;
+        padding: .5em 1.5em;
 
         overflow-y: unset;
       }