branch-coexist: 3 neue decks 223015b-2026 / 223015c-2026 / dhbw-2026 daneben main

per user-request einen branch der main-content UND rewrite-content trägt — saubere separierung statt symlink/merge-conflict.

struktur:
- slides/<course>/ → main-content restored, eigene assets (kein new-demo-leak)
- slides/<course>-2026/ → rewrite-content, eigene assets (komplett kopiert + new demos)

Makefile: COURSES += 223015b-2026 223015c-2026 dhbw-2026 mit eigenen NAME/KAPITEL/DEPLOY/KLAUSUR-konfig. Klausur für b+c=1, dhbw=leer. Deploy-paths /hdm/223015b-2026 etc.

make build durchlaufen für alle 6 decks, 0 fehler.

dedup: 223015c+dhbw assets identisch in beiden ordnern (kein neu-demos auf b ergänzt). 223015b 86 → 120 files in -2026 (= +34 neue eroeffner/usb-c-drei-achsen/container-vs-codec/etc).

slides/223015c-2026/assets/demos/box-model-diagram.html

@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+  <meta charset="UTF-8">
+  <title>Box-Modell Diagramm</title>
+  <style>
+    html, body { margin: 0; padding: 0; background: #fff; font-family: system-ui, sans-serif; }
+    body { padding: 40px; display: inline-block; box-sizing: border-box; }
+    .layer {
+      padding-top: 38px;
+      padding-bottom: 30px;
+      padding-left: 30px;
+      padding-right: 30px;
+      position: relative;
+      border-radius: 4px;
+    }
+    .layer::before {
+      position: absolute;
+      top: 8px; left: 14px;
+      font-size: 0.95rem;
+      font-weight: 700;
+      letter-spacing: 0.02em;
+    }
+    .margin { background: #fde68a; }
+    .margin::before { content: "margin"; color: #92400e; }
+    .border { background: #fca5a5; }
+    .border::before { content: "border"; color: #991b1b; }
+    .padding { background: #86efac; }
+    .padding::before { content: "padding"; color: #166534; }
+    .content {
+      background: #93c5fd;
+      width: 260px;
+      height: 110px;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      color: #1e3a8a;
+      font-weight: 700;
+      font-size: 1.2rem;
+      border-radius: 4px;
+    }
+  </style>
+</head>
+<body>
+  <div class="layer margin">
+    <div class="layer border">
+      <div class="layer padding">
+        <div class="content">content</div>
+      </div>
+    </div>
+  </div>
+</body>
+</html>