Reduce CLS and optimize portrait image

index.html

@@ -55,7 +55,7 @@
 <div class="slide-text">
 <!-- === PORTRET === -->
 <figure class="slide-portrait">
-<img alt="Portret mag. Hermine Merc" decoding="async" height="400" loading="lazy" src="/assets/images/portret-small.webp" width="400"/>
+<img alt="Portret mag. Hermine Merc" decoding="async" height="250" loading="lazy" sizes="(max-width: 768px) 200px, 250px" src="/assets/images/portret-small.webp" srcset="/assets/images/portret-small.webp 250w, /assets/images/portret-small@2x.webp 500w" width="250"/>
 </figure>
 <h2>PSIHOTERAPEVT, VRHUNSKI STROKOVNJAK</h2>
 <!-- === SPREMEMBA: Dodan razred za stil besedila === -->