Unify section spacing rhythm

app/portfolio.css

@@ -234,6 +234,22 @@
     line-height: 1.75;
   }
 
+  .content-stack-default > * + * {
+    margin-top: 1rem;
+  }
+
+  .content-stack-relaxed > * + * {
+    margin-top: 1.5rem;
+  }
+
+  .section-heading-stack > * + * {
+    margin-top: 1rem;
+  }
+
+  .hero-copy-stack > * + * {
+    margin-top: 1rem;
+  }
+
   .type-brand {
     font-size: var(--text-brand);
     line-height: 1;
@@ -544,6 +560,14 @@
     border-color: var(--meta-border-color);
   }
 
+  .project-card-copy > * + * {
+    margin-top: 1.5rem;
+  }
+
+  .project-meta-item > * + * {
+    margin-top: 0.5rem;
+  }
+
   .surface-chip {
     @apply rounded-full border;
     border-color: var(--color-line);
@@ -616,6 +640,10 @@
     line-height: 1.55;
   }
 
+  .contact-card-copy > * + * {
+    margin-top: 0.75rem;
+  }
+
   .contact-value-ltr {
     direction: ltr;
     unicode-bidi: isolate;