[Glitch] Change single-column mode to scroll the whole page

Port aa22b38fdb to glitch-soc

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/styles/components/columns.scss

@@ -17,6 +17,7 @@
     justify-content: center;
     width: 100%;
     height: 100%;
+    min-height: 100vh;
 
     &__pane {
       height: 100%;
@@ -30,6 +31,7 @@
       }
 
       &__inner {
+        position: fixed;
         width: 285px;
         pointer-events: auto;
         height: 100%;
@@ -83,7 +85,6 @@
   flex-direction: column;
   width: 100%;
   height: 100%;
-  background: darken($ui-base-color, 7%);
 }
 
 .column {

app/javascript/flavours/glitch/styles/components/single_column.scss

@@ -127,6 +127,10 @@
     top: 15px;
   }
 
+  .scrollable {
+    overflow: visible;
+  }
+
   @media screen and (min-width: $no-gap-breakpoint) {
     padding: 10px 0;
   }