Gateway submit-as-link loses the underline

A no-requirements gateway alternative renders .alt-submit as an <a>
for plain navigation; strip the link underline so it reads as the
button it's styled to be.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y42TyF8Zu7NGRR2893vNcZ

style/main.css

@@ -861,6 +861,10 @@ textarea:focus {
   padding: 0.75rem 1.4rem;
   cursor: pointer;
   transition: filter 120ms, transform 120ms;
+  /* A gateway alternative renders this as an <a> (navigation, no POST);
+     kill the link chrome so it reads as the button it looks like. */
+  text-decoration: none;
+  display: inline-block;
 }
 
 .alt-submit:hover {