Update nav CTA, VPN pricing, form layout, and power connectors

- Header nav: 'Yhteystiedot' → 'Jätä tarjouspyyntö' with primary color and bold
- VPN: Replace 100M/1G tiers with 1G (alk. €95/kk) and 10G (alk. €129/kk)
- Quote form: Stack unit selects vertically instead of side-by-side
- Replace C19 power connector references with C13 throughout

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

style.css

@@ -166,6 +166,21 @@ a:hover {
     width: 100%;
 }
 
+.nav-cta {
+    color: var(--color-primary) !important;
+    font-weight: 700 !important;
+}
+
+.nav-cta::after {
+    background: var(--color-primary);
+    width: 100% !important;
+    opacity: 0.4;
+}
+
+.header.scrolled .nav-cta {
+    color: var(--color-primary) !important;
+}
+
 .nav-toggle {
     display: none;
     flex-direction: column;