style(site): slower button lift transition

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

site/assets/css/style.css

@@ -457,6 +457,12 @@ section[id] {
 }
 .site-btn.sb-line, .site-btn.sb-ghost { --elb: 2px; }
 
+/* Slower, softer lift (the face colour fades with it). */
+.site-btn.site-btn,
+.gym-switch-btn {
+  transition: transform .5s cubic-bezier(.22, .8, .3, 1), background-color .4s ease, color .4s ease, border-color .4s ease;
+}
+
 .site-btn::before, .site-btn::after,
 .gym-switch-btn::before, .gym-switch-btn::after {
   content: '';
@@ -464,7 +470,7 @@ section[id] {
   pointer-events: none;
   border-radius: calc(var(--fitme-radius) + var(--ring) + var(--elb));
   opacity: 0;
-  transition: opacity .3s ease;
+  transition: opacity .45s ease;
 }
 .site-btn::before, .gym-switch-btn::before {
   inset: calc(-1 * (var(--ring) + var(--elb)));