Fix horizontal scroll overflow due to header animation

The header is now moved up and outside of the body container, now allowing the header to take up a max of 100% of the viewport width. With overflow set to hidden, the animation will go outside the viewport but won't create a scrollbar anymore.

_sass/main.scss

@@ -34,7 +34,7 @@ html {
 }
 
 body {
-  padding: 0 1em;
+  padding: 0;
   font-family: CMU Serif, serif;
   line-height: 1.5;
   background: #0e0e0e;