Fix anatomy diagram display - white background + preserve aspect ratio

workout/template-with-anatomy.html

@@ -77,7 +77,7 @@
       align-items: start;
     }
     .diagram-container {
-      background: rgba(0,0,0,0.3);
+      background: #ffffff;
       border-radius: 8px;
       padding: 12px;
       text-align: center;
@@ -93,20 +93,23 @@
       letter-spacing: 0.5px;
     }
     .diagram-container img {
-      width: 100%;
+      width: auto;
+      max-width: 100%;
       height: auto;
       max-height: 550px;
-      filter: drop-shadow(0 2px 8px rgba(0,0,0,0.3));
+      object-fit: contain;
+      filter: none;
       transition: filter 0.3s, transform 0.3s;
-      border-radius: 4px;
+      display: block;
+      margin: 0 auto;
     }
     .diagram-container.highlighted {
-      box-shadow: 0 0 25px rgba(249, 115, 22, 0.5);
+      box-shadow: 0 0 25px rgba(249, 115, 22, 0.6);
       border-color: rgba(249, 115, 22, 0.8);
       transform: scale(1.02);
     }
     .diagram-container.highlighted img {
-      filter: drop-shadow(0 0 15px rgba(249, 115, 22, 0.7)) brightness(1.15) contrast(1.1);
+      filter: brightness(1.05) contrast(1.05);
     }
     .muscle-label {
       font-size: 0.75rem;