Use own SVG icons instead of text glyphs on the website

Phones turn glyphs such as arrows and crosses into emoji. The viewer, scroll button, video toggle, menus, breadcrumbs, pagers and quote stars now draw SVG.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/assets/lightbox.js

@@ -1,3 +1,6 @@
+/* Symbole als SVG: Schriftzeichen macht ein Telefon zu Emoji. */
+const symbol = (p) => `<svg viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="${p}"/></svg>`;
+
 /*
  * Der Bildbetrachter.
  *
@@ -23,9 +26,9 @@
             <img class="zoom-image" alt="">
             <figcaption class="zoom-caption"></figcaption>
         </figure>
-        <button class="zoom-close" type="button" aria-label="Schließen">×</button>
-        <button class="zoom-prev" type="button" aria-label="Vorheriges Bild">‹</button>
-        <button class="zoom-next" type="button" aria-label="Nächstes Bild">›</button>
+        <button class="zoom-close" type="button" aria-label="Schließen">${symbol('M6 6l12 12M18 6 6 18')}</button>
+        <button class="zoom-prev" type="button" aria-label="Vorheriges Bild">${symbol('M15 5.5 8.5 12l6.5 6.5')}</button>
+        <button class="zoom-next" type="button" aria-label="Nächstes Bild">${symbol('m9 5.5 6.5 6.5L9 18.5')}</button>
         <p class="zoom-counter" aria-live="polite"></p>
     `;
     document.body.append(dialog);
@@ -138,7 +141,7 @@
                 <p class="pdf-title" id="pdf-dialog-title"></p>
                 <a class="pdf-action pdf-download" download>Herunterladen</a>
                 <a class="pdf-action pdf-open" target="_blank" rel="noopener">Im neuen Tab</a>
-                <button class="pdf-close" type="button" aria-label="Schließen">×</button>
+                <button class="pdf-close" type="button" aria-label="Schließen">${symbol('M6 6l12 12M18 6 6 18')}</button>
             </div>
             <iframe class="pdf-frame" title="PDF-Dokument"></iframe>
         `;