diff --git a/slides/223015c/01-geschichte-grundlagen-html.md b/slides/223015c/01-geschichte-grundlagen-html.md
index b7ff8d0..6b7cd39 100644
--- a/slides/223015c/01-geschichte-grundlagen-html.md
+++ b/slides/223015c/01-geschichte-grundlagen-html.md
@@ -1388,7 +1388,7 @@ Accessibility ist eingebaut
 </details>
 ```
 
-https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details
+<small>→ [MDN: `<details>`](https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details)</small>
 
 ---
 
@@ -1403,7 +1403,7 @@ https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details
 </details>
 ```
 
-https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details#erstellen_einer_offenen_disclosure-box
+<small>→ [MDN: `<details open>`](https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details#erstellen_einer_offenen_disclosure-box)</small>
 
 ---
 
@@ -1416,7 +1416,7 @@ https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/details#erstel
 <button>Add to favorites</button>
 ```
 
-https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/button
+<small>→ [MDN: `<button>`](https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/button)</small>
 
 ---
 
@@ -1431,7 +1431,7 @@ https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/button
   size="10" />
 ```
 
-https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/input
+<small>→ [MDN: `<input>`](https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/input)</small>
 
 ---
 
@@ -1448,7 +1448,7 @@ https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/input
 </dialog>
 ```
 
-https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/dialog
+<small>→ [MDN: `<dialog>`](https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/dialog)</small>
 
 
 ---
@@ -1456,7 +1456,7 @@ https://developer.mozilla.org/de/docs/Web/HTML/Reference/Elements/dialog
 <!-- _class: lead -->
 
 # "Barrierefreiheit"
-## a11y – Accessibility
+## Accessibility (a11y)
 
 ---
 
@@ -1622,7 +1622,7 @@ Gesetzlich meist Level AA gefordert
 
 # Perceivable: Wahrnehmbar
 
-![bg right:38%](./assets/demos/contrast-levels.png)
+![bg right:35% fit](./assets/demos/contrast-levels.png)
 
 **Textalternativen für Nicht-Text:**
 ```html
diff --git a/slides/223015c/assets/demos/contrast-levels.png b/slides/223015c/assets/demos/contrast-levels.png
index 86c9293..e45fe2c 100644
Binary files a/slides/223015c/assets/demos/contrast-levels.png and b/slides/223015c/assets/demos/contrast-levels.png differ