symmetric root margin

Author: mbostock

docs/observable.tmpl

@@ -54,7 +54,7 @@
     <script type="module">
       document.querySelector("#edit-page").href += `/edit/main/docs${location.pathname + (location.pathname.endsWith("/") ? "index" : "")}.html`;
     </script>
-    <footer style="width: 100vw; margin: 2rem calc((100% - 100vw) / 2) -16px; padding-bottom: 16px; background-color: var(--theme-foreground); color: var(--theme-background); font: 12px/normal var(--sans-serif);">
+    <footer style="width: 100vw; margin: 2rem calc((100% - 100vw) / 2) -32px; padding-bottom: 16px; background-color: var(--theme-foreground); color: var(--theme-background); font: 12px/normal var(--sans-serif);">
       <div style="display: flex; flex-wrap: wrap; max-width: var(--max-width); padding: 2rem 1rem; margin: auto; gap: 2rem;">
         <div>
           <a title="Observable" target="_blank" href="https://observablehq.com/" style="color: inherit;">

src/styles/global.css

@@ -17,7 +17,7 @@ html {
   -moz-osx-font-smoothing: grayscale;
   background: var(--theme-background);
   color: var(--theme-foreground);
-  margin-top: 16px;
+  margin: 16px 0;
   padding: 16px 24px;
 }