diff --git a/AGENT.md b/AGENT.md
index 6f33123..bc6dbbd 100644
--- a/AGENT.md
+++ b/AGENT.md
@@ -24,7 +24,7 @@ Minimal PHP for modern conveniences. Decade-scale maintainability. No volatile d
 
 ## Code Style
 **PHP:** Arrow functions, null coalescing, match. Type hints where practical. Single-purpose functions.
-**CSS:** Variables, native nesting, grid. `clamp()` over `@media`. Relative units.
+**CSS:** Variables, native nesting, grid. `clamp()` over `@media`. Relative units. Margin-top only (reset: `* { margin-bottom: 0 }`).
 **Templates:** `<?= htmlspecialchars($var) ?>` for UGC. `<?= $content ?>` for pre-rendered HTML.
 
 ## Project Structure