css: tweak page box model to support scrolling background

Author: towerofnix

src/static/site6.css

@@ -32,7 +32,9 @@
 /* Layout - Common */
 
 body {
-  margin: 10px;
+  position: relative;
+  margin: 0;
+  padding: 10px;
   overflow-y: scroll;
 }
 
@@ -41,8 +43,8 @@ body::before {
   position: fixed;
   top: 0;
   left: 0;
-  width: 100%;
-  height: 100%;
+  width: 100vw;
+  height: 100vh;
   z-index: -1;
 
   /* NB: these are 100 LVW, "largest view width", etc.
@@ -56,7 +58,7 @@ body::before {
 
 #page-container {
   max-width: 1100px;
-  margin: 10px auto 50px;
+  margin: 0 auto 40px;
   padding: 15px 0;
 }