[DESIGN-003] Add layered hero section with floating elements (feat)

- Added animated background gradient layers (3 floating blobs)
- Created floating stats cards around main illustration
- Implemented smooth animations (floatSlow, scaleFloat)
- Added depth and parallax effects
- Improved visual hierarchy with z-index layering
- Enhanced dark theme compatibility
- All animations are smooth and GPU-accelerated

Inspired by modern cloud hosting landing pages

assets/custom.css

@@ -29,3 +29,20 @@ body {
     50% { transform: translateY(-20px); }
 }
 
+@keyframes floatSlow {
+    0%, 100% { transform: translateY(0px) translateX(0px); }
+    25% { transform: translateY(-15px) translateX(10px); }
+    50% { transform: translateY(-30px) translateX(0px); }
+    75% { transform: translateY(-15px) translateX(-10px); }
+}
+
+@keyframes rotate {
+    0% { transform: rotate(0deg); }
+    100% { transform: rotate(360deg); }
+}
+
+@keyframes scaleFloat {
+    0%, 100% { transform: scale(1) translateY(0px); }
+    50% { transform: scale(1.05) translateY(-15px); }
+}
+