Using consistent margins for tips and code blocks.

docs/extra.less

@@ -322,6 +322,7 @@ dl.note,dl.pre,dl.post,dl.invariant,dl.warning,dl.attention,dl.deprecated,dl.bug
 	border-radius:4px;
 	padding:1em;
 	text-shadow:0 1px 1px hsl(0,0%,100%);
+	margin:1em 0;
 }
 
 .note a,.pre a,.post a,.invariant a,.warning a,.attention a,.deprecated a,.bug a,.todo a,.test a,.note a:visited,.pre a:visited,.post a:visited,.invariant a:visited,.warning a:visited,.attention a:visited,.deprecated a:visited,.bug a:visited,.todo a:visited,.test a:visited {
@@ -339,6 +340,7 @@ div.fragment,pre.fragment {
 	padding:1em;
 	overflow:auto;
 	border-left:4px solid hsl(0,0%,80%);
+	margin:1em 0;
 }
 
 .lineno a,.lineno a:visited,.line,pre.fragment {