Re work modal scrolling

src/app/components/InfoSignatures.svelte

@@ -1,32 +1,35 @@
 <script lang="ts">
   import Link from "@lib/components/Link.svelte"
   import Button from "@lib/components/Button.svelte"
+  import Modal from "@lib/components/Modal.svelte"
+  import ModalBody from "@lib/components/ModalBody.svelte"
   import ModalHeader from "@lib/components/ModalHeader.svelte"
 
   const back = () => history.back()
 </script>
 
-<div class="column gap-4">
-  <ModalHeader>
-    {#snippet title()}
-      <div>What are digital signatures?</div>
-    {/snippet}
-  </ModalHeader>
-  <p>
-    Most online services ask their users to trust them that they're being honest, and they usually
-    are. However, traditional social media platforms have the ability to <strong
-      >create forged content</strong> that can appear to be genuinely authored, but which are actually
-    counterfeit.
-  </p>
-  <p>
-    On <Link external href="https://nostr.com/">Nostr</Link>, all your content is authenticated
-    using <strong>digital signatures</strong>, which cryptographically tie a particular person to a
-    given post or message.
-  </p>
-  <p>
-    The result is that you don't normally have to trust service providers not to tamper with the
-    information flowing through the network — instead, your client software can prove that a given
-    piece of data is authentic.
-  </p>
-  <Button class="btn btn-primary" onclick={back}>Got it</Button>
-</div>
+<Modal
+  ><ModalBody>
+    <ModalHeader>
+      {#snippet title()}
+        <div>What are digital signatures?</div>
+      {/snippet}
+    </ModalHeader>
+    <p>
+      Most online services ask their users to trust them that they're being honest, and they usually
+      are. However, traditional social media platforms have the ability to <strong
+        >create forged content</strong> that can appear to be genuinely authored, but which are actually
+      counterfeit.
+    </p>
+    <p>
+      On <Link external href="https://nostr.com/">Nostr</Link>, all your content is authenticated
+      using <strong>digital signatures</strong>, which cryptographically tie a particular person to
+      a given post or message.
+    </p>
+    <p>
+      The result is that you don't normally have to trust service providers not to tamper with the
+      information flowing through the network — instead, your client software can prove that a given
+      piece of data is authentic.
+    </p>
+    <Button class="btn btn-primary" onclick={back}>Got it</Button>
+  </ModalBody></Modal>