Improve presentation of supporting links on the terms page

public/stylesheets/common.css

@@ -734,7 +734,7 @@ div#contributorTerms {
   border: 1px solid black;
   padding: 4px;
   overflow: auto;
-  width: 80%;
+  width: 95%;
   height: 400px;
 }
 
@@ -762,7 +762,7 @@ div#contributorTerms img {
 }
 
 form#termsForm {
-  width: 80%;
+  width: 95%;
   margin-bottom: 3em;
 }
 
@@ -778,6 +778,14 @@ form#termsForm input#agree {
   margin-left: 50px;
 }
 
+p#contributorGuidance {
+  background-color: #f5f5ff;
+  border: 1px solid #f3f3ff;
+  border-radius: 15px;
+  -moz-border-radius: 15px;
+  padding: 10px;
+}
+
 /* Rules for the account settings page */
 
 #accountForm td {