feat: flowing gold side lines + pure glass header

- DecorativeLines: SVG flowing bezier curves on both sides, gold
  gradient with fade at top/bottom, desktop only (xl+), starts
  after hero section
- Header: pure backdrop-blur-xl glass with no bg color overlay,
  subtle border-white/8% bottom line
- Removed old straight CSS lines from body

src/app/globals.css

@@ -26,36 +26,6 @@ body {
   overflow-x: hidden;
 }
 
-/* ===== Decorative side lines (desktop only) ===== */
-
-@media (min-width: 1280px) {
-  body::before,
-  body::after {
-    content: "";
-    position: fixed;
-    top: 0;
-    bottom: 0;
-    width: 1px;
-    z-index: 40;
-    pointer-events: none;
-    background: linear-gradient(
-      180deg,
-      transparent 0%,
-      rgba(201, 169, 110, 0.15) 15%,
-      rgba(201, 169, 110, 0.25) 50%,
-      rgba(201, 169, 110, 0.15) 85%,
-      transparent 100%
-    );
-  }
-
-  body::before {
-    left: clamp(16px, 3vw, 48px);
-  }
-
-  body::after {
-    right: clamp(16px, 3vw, 48px);
-  }
-}
 
 /* ===== Selection ===== */