diff --git a/src/app.css b/src/app.css
index a7f6844..89f75e8 100644
--- a/src/app.css
+++ b/src/app.css
@@ -7,20 +7,12 @@
     src: url('/fonts/inter-v18-latin-regular.woff2') format('woff2'); /* Chrome 36+, Opera 23+, Firefox 39+, Safari 12+, iOS 10+ */
 }
 
-* {
-    --color-primary-a0: #ffffff;
-    --color-primary-a10: #e1e6fe;
-    --color-primary-a20: #c2cdfd;
-    --color-primary-a30: #a1b5fb;
-    --color-primary-a40: #7d9df9;
-    --color-primary-a50: #5087f6;
-    --color-primary-a60: #436bc0;
-    --color-primary-a70: #364f8c;
-    --color-primary-a80: #28365c;
-    --color-primary-a90: #191e2f;
-    --color-primary-a100: #000000;
-    --text-color: black;
+pre {
+    max-width: 100%;
+    overflow: scroll;
+}
 
+* {
     box-sizing: border-box;
     font-size: inherit;
 }
@@ -29,13 +21,13 @@ html, body {
     position: relative;
     margin: 0;
     padding: 0;
-    background-color: white;
     font-size: 1rem;
+    background-color: var(--tg-theme-bg-color);
 }
 
 p, a, h1, h2, h3, h4, h5, h6 {
     font-family: Inter, Arial, sans-serif;
-    color: var(--text-color);
+    color: var(--tg-theme-text-color);
 }
 
 h1, h2, h3, h4, h5, h6 {
@@ -58,3 +50,29 @@ svg {
     max-width: 100%;
     height: auto;
 }
+
+a {
+    color: var(--tg-theme-link-color);
+}
+
+button {
+    padding: 0.45rem 0.65rem;
+
+    background-color: var(--tg-theme-button-color);
+    color: var(--tg-theme-button-text-color);
+    font-size: 1.35rem;
+    border: none;
+
+    &:disabled {
+        filter: grayscale(1.0);
+    }
+}
+
+label {
+    color: var(--tg-theme-text-color);
+}
+
+input {
+    color: var(--tg-theme-text-color);
+    background-color: var(--tg-theme-secondary-bg-color);
+}
\ No newline at end of file
diff --git a/src/hooks.client.js b/src/hooks.client.js
index 51625bf..d91fbfc 100644
--- a/src/hooks.client.js
+++ b/src/hooks.client.js
@@ -1,4 +1,4 @@
-import {initializePocketBase} from "$lib/pocketbase.js";
+import { initializePocketBase } from "$lib/pocketbase.js";
 
 export const init = async () => {
    initializePocketBase()
diff --git a/src/lib/components/ContainerGridSingle.svelte b/src/lib/components/ContainerGridSingle.svelte
index d8dc5db..3cce760 100644
--- a/src/lib/components/ContainerGridSingle.svelte
+++ b/src/lib/components/ContainerGridSingle.svelte
@@ -13,6 +13,8 @@
 
 <style>
     .container-grid {
+        max-width: 800px;
+        margin: 0 auto;
         display: grid;
         height: 100vh;
         grid-template-columns: [content-full-start] 2rem [content-start] 1fr [content-end] 2rem [content-full-end];
@@ -30,7 +32,5 @@
         position: sticky;
         grid-column: content;
         grid-row: content-footer;
-
-        background-color: white;
     }
 </style>
diff --git a/src/lib/components/EventList.svelte b/src/lib/components/EventList.svelte
index 1cf288e..18e1381 100644
--- a/src/lib/components/EventList.svelte
+++ b/src/lib/components/EventList.svelte
@@ -20,8 +20,6 @@
 <style>
     .event {
         padding: 0.5rem 1rem;
-
-        border: 2px solid #00000055;
-        border-radius: 3%;
+        background-color: var(--tg-theme-secondary-bg-color);
     }
 </style>
diff --git a/src/lib/components/EventRegisterButton.svelte b/src/lib/components/EventRegisterButton.svelte
index e69de29..762d1a8 100644
--- a/src/lib/components/EventRegisterButton.svelte
+++ b/src/lib/components/EventRegisterButton.svelte
@@ -0,0 +1,39 @@
+<script>
+    import {useTelegram} from "$lib/telegram.svelte.js";
+
+    const { eventId = null } = $props();
+    const telegram = useTelegram();
+    let dataPrivacyConsent = $state(false);
+    let ageConsent = $state(false)
+    let buttonEnabled = $derived(() => dataPrivacyConsent && ageConsent && telegram?.initData);
+</script>
+
+{#if eventId}
+    {#if telegram?.initData}
+        <form method="POST" action="?/register">
+            <input name="init-data" type="hidden" value={telegram?.initData} />
+            <input name="event-id" type="hidden" value={eventId} />
+            <div class="form-row">
+                <label><input type="checkbox" bind:checked={dataPrivacyConsent}> Ich stimme zu das meine Daten bis zu 14 Tagen nach der Veranstaltung beibehalten werden</label>
+            </div>
+            <div class="form-row">
+                <label><input type="checkbox" bind:checked={ageConsent}> Ich bin mindestens 16 Jahre alt oder komme in Begleitung eines Erwachsenen</label>
+            </div>
+            <div class="form-row">
+                <button disabled={!buttonEnabled()}>Anmelden</button>
+            </div>
+        </form>
+    {:else}
+        <p>Bitte öffne diese Mini App im Telegram Bot um dich anzumelden! <a target="_blank" href="https://t.me/doggoatbot?startapp">Öffnen</a></p>
+    {/if}
+{:else}
+    <p>Invalide Event-ID</p>
+{/if}
+
+<style>
+    form {
+        display: flex;
+        flex-flow: column wrap;
+        gap: 1rem;
+    }
+</style>
\ No newline at end of file
diff --git a/src/lib/components/FooterNavigation.svelte b/src/lib/components/FooterNavigation.svelte
index b578873..4320b33 100644
--- a/src/lib/components/FooterNavigation.svelte
+++ b/src/lib/components/FooterNavigation.svelte
@@ -7,12 +7,15 @@
         <li class:selected={page.url.pathname === "/"}>
             <a href="/" >Start</a>
         </li>
-        <li class:selected={page.url.pathname === "/events"}>
+        <li class:selected={page.url.pathname.startsWith("/events")}>
             <a href="/events">Events</a>
         </li>
         <li class:selected={page.url.pathname === "/rules"}>
             <a href="/rules">Regeln</a>
         </li>
+        <!--<li class:selected={page.url.pathname === "/debug"}>
+            <a href="/debug">Debug</a>
+        </li>-->
     </ul>
 </nav>
 
@@ -29,15 +32,17 @@
     li {
         transition: border-bottom-color linear 0.2s;
         padding: 0.6rem 0.45rem;
-        border-bottom: 3px var(--color-primary-a80) solid;
+        border-bottom: 3px var(--tg-theme-button-color) solid;
+        filter: grayscale(0.8);
 
         &.selected {
-            border-bottom: 3px var(--color-primary-a40) solid;
+            filter: none;
+            border-bottom: 3px var(--tg-theme-button-color) solid;
         }
     }
 
     a {
-        font-size: 1.5rem;
+        font-size: 1.35rem;
         text-decoration: none;
     }
 </style>
\ No newline at end of file
diff --git a/src/lib/telegram.svelte.js b/src/lib/telegram.svelte.js
index e69de29..d44c383 100644
--- a/src/lib/telegram.svelte.js
+++ b/src/lib/telegram.svelte.js
@@ -0,0 +1,34 @@
+const telegram = $state({user: null, initData: null})
+let checkCount = $state(0);
+
+export function useTelegram() {
+    const checkTelegramUser = () => {
+        checkCount = checkCount+1;
+        if (typeof window === 'undefined') {
+            setTimeout(checkTelegramUser, 100);
+            return;
+        }
+        telegram.initData = Telegram?.WebApp?.initData;
+        console.log(Telegram?.WebApp);
+        if (!telegram.initData) {
+            setTimeout(checkTelegramUser, 100);
+            console.warn("initData could not be loaded");
+            return;
+        }
+        const searchParams = new URLSearchParams(telegram.initData);
+        const tempUser = searchParams.get('user');
+        if (!tempUser) {
+            console.warn("User could not be loaded");
+            return;
+        }
+        telegram.user = JSON.parse(tempUser);
+    }
+
+    $effect(() => {
+        setTimeout(checkTelegramUser, 100);
+    });
+
+    return telegram
+}
+
+
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 728b816..f95c60d 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -3,12 +3,6 @@
     import FooterNavigation from "$lib/components/FooterNavigation.svelte";
     import ContainerGridSingle from "$lib/components/ContainerGridSingle.svelte";
     const { children } = $props();
-
-    $effect(() => {
-        Telegram?.WebApp?.ready();
-        Telegram?.WebApp?.setBackgroundColor('FFFFFF');
-    });
-
 </script>
 
 <ContainerGridSingle>
@@ -23,5 +17,6 @@
 <style>
     .footer-inner {
         margin-top: 1rem;
+        background-color: var(--tg-theme-bg-color);
     }
 </style>
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 4d6d804..e792fc2 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -1,25 +1,19 @@
 <script>
     import RoundedAvatar from "$lib/components/RoundedAvatar.svelte";
-    let user = $state(null);
+    import { useTelegram } from "$lib/telegram.svelte.js";
+
+    const telegram = useTelegram();
 
-    $effect(() => {
-        const searchParams = new URLSearchParams(Telegram?.WebApp?.initData);
-        const tempUser = searchParams.get('user');
-        if (!tempUser) {
-            console.warn("User could not be loaded");
-            return;
-        }
-        user = JSON.parse(tempUser);
-    })
 </script>
 
 <section id="intro">
-    {#if user}
+    {#if telegram && telegram?.user}
+        {@const user = telegram.user}
         <RoundedAvatar src={user?.photo_url}></RoundedAvatar>
-        <h2>Hallo {user.first_name}!</h2>
+        <h2>Hallo {user?.first_name}!</h2>
     {:else}
         <RoundedAvatar src={null}></RoundedAvatar>
         <h2>Hallo Besucher!</h2>
     {/if}
-    <p>Du befinest dich auf der Anmeldeseite des Kölner Stammtischs. Schau dir die unteren Menüpunkte an, falls du mehr erfahren möchtest.</p>
+    <p>Du befindest dich auf der Mini App des Kölner Stammtischs. Schau dir die unteren Menüpunkte an, falls du mehr erfahren möchtest.</p>
 </section>
diff --git a/src/routes/debug/+page.svelte b/src/routes/debug/+page.svelte
index e69de29..cfc1bcf 100644
--- a/src/routes/debug/+page.svelte
+++ b/src/routes/debug/+page.svelte
@@ -0,0 +1,8 @@
+<script>
+    import { useTelegram } from "$lib/telegram.svelte.js";
+    const telegram = useTelegram()
+</script>
+
+<pre>
+    {JSON.stringify(telegram.user, null, 4)}
+</pre>
\ No newline at end of file
diff --git a/src/routes/events/[slug]/+page.server.js b/src/routes/events/[slug]/+page.server.js
index e69de29..30bd42a 100644
--- a/src/routes/events/[slug]/+page.server.js
+++ b/src/routes/events/[slug]/+page.server.js
@@ -0,0 +1,34 @@
+import { subtle } from 'node:crypto';
+import {PRIVATE_TELEGRAM_BOT_ID, PRIVATE_TELEGRAM_PUBLIC_KEY} from "$env/static/private";
+
+export const actions = {
+    register: async ({ request }) => {
+        const formData = await request.formData();
+        if (!formData) return { success: false, error: "No valid form data was provided" };
+
+        const initDataUrlEncoded = formData.get('init-data');
+        if (!initDataUrlEncoded) return { success: false, error: "No valid form data was provided" };
+
+        const eventId = formData.get('event-id');
+        if (!eventId) return { success: false, error: "Missing event-id" };
+
+        const dataArrayParams = new URLSearchParams(initDataUrlEncoded)
+        const initDataArray = [...dataArrayParams];
+        const signature = dataArrayParams.get('signature');
+        if (!signature) return { success: false, error: "No signature was provided" };
+        initDataArray.sort((d1, d2) => d1[0].charCodeAt(0) - d2[0].charCodeAt(0));
+
+        const checkString = initDataArray.reduce((acc, currentValue) => {
+            if (['signature', 'hash'].includes(currentValue[0])) return acc;
+            acc.push(currentValue.join("="))
+            return acc;
+        }, [`${PRIVATE_TELEGRAM_BOT_ID}:WebAppData`]).join("\n")
+
+        const algo = 'Ed25519';
+        const key = await subtle.importKey("raw", Buffer.from(PRIVATE_TELEGRAM_PUBLIC_KEY, 'hex'), algo, false, ['verify']);
+        const validSignature = await subtle.verify(algo, key, Buffer.from(signature, 'base64url'), Buffer.from(checkString));
+        if (!validSignature) return { success: false, error: "Invalid signature" }
+
+        return { success: true, error: null }
+    }
+}
\ No newline at end of file
diff --git a/src/routes/events/[slug]/+page.svelte b/src/routes/events/[slug]/+page.svelte
index 782584f..e17578e 100644
--- a/src/routes/events/[slug]/+page.svelte
+++ b/src/routes/events/[slug]/+page.svelte
@@ -5,9 +5,12 @@
     import {Tile} from 'ol/layer';
     import {useGeographic} from "ol/proj";
     import {onMount} from "svelte";
+    import EventRegisterButton from "$lib/components/EventRegisterButton.svelte";
+    import {useTelegram} from "$lib/telegram.svelte.js";
 
     const { data } = $props();
     const { event } = data;
+    const telegram = useTelegram();
 
     let mapRef;
 
@@ -43,14 +46,36 @@
         <p>{event?.description ?? "No description"}</p>
     {/if}
 
+    {#if event?.start}
+        {@const date = new Date(event.start)}
+        <div class="event-date-time">
+            <h2>Wann?</h2>
+            {#if telegram?.user?.language_code}
+                <p>{date.toLocaleDateString(telegram.user.language_code, {dateStyle: 'long'})}<br />
+                    {date.toLocaleTimeString(telegram.user.language_code, {timeStyle: 'long'})}</p>
+            {:else}
+                <p>{date.toLocaleDateString('en', {dateStyle: 'long'})}<br />
+                    {date.toLocaleTimeString('en', {timeStyle: 'long'})}</p>
+            {/if}
+        </div>
+    {/if}
+
     <div class="event-location-details">
-        <h2>Location</h2>
+        <h2>Wo?</h2>
         <p class="location-address">
             {event?.expand?.location?.name}<br />
-            {event?.expand?.location?.address}
+            {#each event?.expand?.location?.address.split(', ') as part}
+                {part}<br />
+            {/each}
         </p>
         <div class="event-map" bind:this={mapRef}></div>
     </div>
+
+</div>
+
+<div class="event-register">
+    <h2>Anmeldung</h2>
+    <EventRegisterButton eventId={event?.id} />
 </div>
 
 <style>
@@ -59,13 +84,21 @@
         height: 50vh;
     }
 
-    .event-location-details {
-        padding: 0 1rem 1rem 1rem;
-        border: 2px solid #00000055;
-        border-radius: 3%;
+    .event-location-details, .event-register, .event-date-time{
+        padding: 1rem;
+        background-color: var(--tg-theme-secondary-bg-color);
+        border-radius: 5%;
+
+        h2 {
+            margin-top: 0;
+        }
     }
 
     .location-address {
         margin-top: 0;
     }
+
+    .event-register, .event-date-time {
+        margin: 1rem 0;
+    }
 </style>
\ No newline at end of file
diff --git a/src/routes/rules/+page.svelte b/src/routes/rules/+page.svelte
index 197d9ac..d0d47de 100644
--- a/src/routes/rules/+page.svelte
+++ b/src/routes/rules/+page.svelte
@@ -5,6 +5,7 @@
 
 <style>
     iframe {
+        background-color: white;
         height: 100%;
         width: 100%;
     }