fix: improve pagination styling for active page and next button

Match padding and sizing for active page number and next button
to match inactive page buttons.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/views/static/css/kafka.css

@@ -465,9 +465,17 @@ main {
 }
 
 .page-current {
+  min-width: 40px;
+  height: 40px;
+  padding: 0 0.75rem;
+  border: 1px solid var(--accent) !important;
+  border-radius: var(--radius-sm);
   background: var(--accent) !important;
-  border-color: var(--accent) !important;
   color: #fff !important;
+  font-size: 0.9rem;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
 }
 
 /* ============================================================