Merge pull request #199 from Johann150/main

fix (missing) margin collapses for sections

simple.css

@@ -341,7 +341,9 @@ article, fieldset, dialog {
 }
 
 article h2:first-child,
-section h2:first-child {
+section h2:first-child,
+article h3:first-child,
+section h3:first-child {
   margin-top: 1rem;
 }
 
@@ -359,6 +361,10 @@ section:first-child {
   padding-top: 0;
 }
 
+section + section {
+  margin-top: 0;
+}
+
 section:last-child {
   border-bottom: 0;
   padding-bottom: 0;