fix: make axolotl visible — invert colors + increase opacity

- Added invert(1) filter to make black axolotl white on dark background
- Increased opacity from 0.12 to 0.15
- Image was invisible because black-on-black, now white-on-black

Author: Pakrohk

index.html

@@ -35,10 +35,10 @@
       position: fixed;
       top: 0; left: 0; right: 0; bottom: 0;
       background: url('axolotl.png') center/cover no-repeat;
-      opacity: 0.12;
+      opacity: 0.15;
       pointer-events: none;
       z-index: 0;
-      filter: grayscale(1);
+      filter: invert(1) grayscale(1);
     }
 
     /* ── Nav ── */