fix klausur slide pdf rendering with @media print fallback

courses/223015b/slides/01-grundlagen.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/02-bild-audio-video.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 </style>
 
 <!-- _class: invert -->

courses/223015b/slides/2025-12-19-termin-0-intro.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/2025-12-19-termin-1-grundlagen-text-audio.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/2026-01-09-termin-2-bild-audio-video.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/2026-01-23-termin-3-speichermedien-schnittstellen.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/2026-01-30-termin-4-distribution-apis-zukunft.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015b/slides/2026-xx-xx-termin-5-vertiefung-offene-fragen.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #e3f2fd !important;
+  }
+}
 section.aufgabe {
   background: #e3f2fd !important;
 }

courses/223015c/slides/2025-12-20-termin-1-geschichte-grundlagen-html.md

@@ -55,7 +55,12 @@ section.klausur {
     #fce4ec 40px,
     #fff 40px,
     #fff 80px
-  );
+  ) !important;
+}
+@media print {
+  section.klausur {
+    background: #fce4ec !important;
+  }
 }
 section.aufgabe {
   background: #fce4ec !important;

courses/223015c/slides/2026-01-10-termin-2-netzwerke-protokolle-css.md

@@ -57,6 +57,11 @@ section.klausur {
     #fff 80px
   ) !important;
 }
+@media print {
+  section.klausur {
+    background: #fce4ec !important;
+  }
+}
 section.aufgabe {
   background: #fce4ec !important;
 }

courses/223015c/slides/2026-01-24-termin-3-interaktivitaet-javascript.md

@@ -55,7 +55,12 @@ section.klausur {
     #fce4ec 40px,
     #fff 40px,
     #fff 80px
-  );
+  ) !important;
+}
+@media print {
+  section.klausur {
+    background: #fce4ec !important;
+  }
 }
 section.aufgabe {
   background: #fce4ec !important;