Fix highlight alignment by removing problematic CSS transforms

Co-authored-by: jessephus <[email protected]>

Author: Copilot

styles.css

@@ -207,9 +207,7 @@ header h1 {
 }
 
 .flute-key-svg .key-highlight {
-    transition: opacity 0.2s ease-in-out, transform 0.2s ease-in-out;
-    transform-origin: center;
-    will-change: transform;
+    transition: opacity 0.2s ease-in-out;
 }
 
 .flute-key-svg .key-highlight.hit-pulse {
@@ -218,15 +216,12 @@ header h1 {
 
 @keyframes hit-pulse-animation {
     0% {
-        transform: scale(1);
         opacity: 1;
     }
     50% {
-        transform: scale(1.3);
         opacity: 1;
     }
     100% {
-        transform: scale(1);
         opacity: 0.9;
     }
 }