refactor app grid

- make content container scrollable, more flexible

src/assets/css/global.scss

@@ -67,7 +67,7 @@ a {
 .l-container {
   display: grid;
   grid-template-columns: min-content 1fr min-content;
-  grid-template-rows: 3rem 1fr 1fr;
+  grid-template-rows: 3.5rem 1fr 1fr;
   grid-auto-flow: row;
   grid-template-areas:
     "l-sidebar nav search-input"
@@ -129,10 +129,11 @@ a {
   display: flex;
 }
 
-.content {
+#acontent {
   grid-area: content;
-  padding: 0;
   max-width: 1504px;
+  padding: $small;
+  overflow: auto;
 
   .nav {
     margin: $small;