style: minor improvements to submit item styling

Author: kyrers

web/src/pages/SubmitItem/Policy/Info.tsx

@@ -12,7 +12,7 @@ const alertMessage =
 const Info: React.FC = () => {
   return (
     <div className={cn("flex justify-center w-[84vw] mb-8", landscapeWitdhCalc)}>
-      <AlertMessage variant="info" title="Important" msg={alertMessage} />
+      <AlertMessage className="[&_h2]:m-0" variant="info" title="Important" msg={alertMessage} />
     </div>
   );
 };

web/src/pages/SubmitItem/Preview/index.tsx

@@ -4,13 +4,17 @@ import { Card } from "@kleros/ui-components-library";
 import NavigationButtons from "../NavigationButtons";
 import ListDisplay from "./ListDisplay";
 import ItemDisplay from "./ItemDisplay";
+import clsx from "clsx";
 
 const Preview: React.FC = () => {
   return (
     <div className="flex flex-col items-center w-full py-0" style={{ paddingInline: responsiveSize(10, 130) }}>
       <h2 className="text-center font-semibold mb-8 w-[84vw] lg:w-auto">Preview</h2>
       <Card
-        className="relative flex flex-col gap-8 w-full h-auto min-h-[100px]"
+        className={clsx(
+          "relative flex flex-col gap-8 w-full h-auto min-h-[100px]",
+          "border-dashed border-klerosUIComponentsPrimaryBlue bg-klerosUIComponentsMediumBlue"
+        )}
         style={{
           marginBottom: responsiveSize(0, 16),
           paddingBlock: responsiveSize(24, 48),