fix: restore body background to transparent so 3D canvas shows through

The canvas is at z-index:-2 (behind body). Setting body to #000
made it opaque and hid the canvas. Keep html black as fallback,
body transparent so the fixed canvas behind it remains visible.

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via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

Author: 3 people

docs/projects/nthpartyfinder/index.html

@@ -54,7 +54,7 @@
   font-size: 16px;
   line-height: 1.65;
   color: var(--text);
-  background: #000;
+  background: transparent;
   -webkit-font-smoothing: antialiased;
   padding-top: 68px;
 }