fix: tighten create page spacing

apps/ui/src/styles.css

@@ -316,7 +316,10 @@ button {
 }
 
 .main-content {
+  width: 100%;
+  max-width: 1480px;
   padding: 28px;
+  margin: 0 auto;
   flex: 1;
 }
 
@@ -400,6 +403,11 @@ button {
   gap: 16px;
 }
 
+.builder-stack {
+  width: 100%;
+  max-width: 1320px;
+}
+
 .page-section,
 .builder-card,
 .operation-card,
@@ -425,9 +433,16 @@ button {
   align-items: flex-start;
   justify-content: space-between;
   gap: 12px;
+}
+
+.section-header {
   margin-bottom: 16px;
 }
 
+.builder-card-header {
+  padding: 20px 24px 0;
+}
+
 .section-header h2,
 .builder-card-header h2 {
   margin: 0 0 2px;
@@ -452,6 +467,7 @@ button {
 .builder-card-body {
   display: grid;
   gap: 16px;
+  padding: 0 24px 24px;
 }
 
 .proto-grid {
@@ -920,6 +936,7 @@ button {
 }
 
 .field-inline {
+  width: 100%;
   max-width: 420px;
 }
 
@@ -1096,6 +1113,10 @@ pre {
   .main-content {
     padding: 20px;
   }
+
+  .builder-stack {
+    max-width: none;
+  }
 }
 
 @media (max-width: 820px) {
@@ -1116,4 +1137,11 @@ pre {
   .hero-metrics {
     grid-template-columns: 1fr;
   }
+
+  .builder-card-header,
+  .builder-card-body,
+  .page-section {
+    padding-left: 16px;
+    padding-right: 16px;
+  }
 }