Fix page body not being scrollable in admin layout (#11893)

Hide navigation behind hamburger icon on small screens in admin layout

app/javascript/styles/mastodon/admin.scss

@@ -5,21 +5,66 @@ $content-width: 840px;
 .admin-wrapper {
   display: flex;
   justify-content: center;
-  height: 100%;
+  width: 100%;
+  min-height: 100vh;
 
   .sidebar-wrapper {
-    flex: 1 1 $sidebar-width;
-    height: 100%;
-    background: $ui-base-color;
-    display: flex;
-    justify-content: flex-end;
+    min-height: 100vh;
+    overflow: hidden;
+    pointer-events: none;
+    flex: 1 1 auto;
+
+    &__inner {
+      display: flex;
+      justify-content: flex-end;
+      background: $ui-base-color;
+      height: 100%;
+    }
   }
 
   .sidebar {
     width: $sidebar-width;
-    height: 100%;
     padding: 0;
-    overflow-y: auto;
+    pointer-events: auto;
+
+    &__toggle {
+      display: none;
+      background: lighten($ui-base-color, 8%);
+      height: 48px;
+
+      &__logo {
+        flex: 1 1 auto;
+
+        a {
+          display: inline-block;
+          padding: 15px;
+        }
+
+        svg {
+          fill: $primary-text-color;
+          height: 20px;
+          position: relative;
+          bottom: -2px;
+        }
+      }
+
+      &__icon {
+        display: block;
+        color: $darker-text-color;
+        text-decoration: none;
+        flex: 0 0 auto;
+        font-size: 20px;
+        padding: 15px;
+      }
+
+      a {
+        &:hover,
+        &:focus,
+        &:active {
+          background: lighten($ui-base-color, 12%);
+        }
+      }
+    }
 
     .logo {
       display: block;
@@ -52,6 +97,9 @@ $content-width: 840px;
         transition: all 200ms linear;
         transition-property: color, background-color;
         border-radius: 4px 0 0 4px;
+        white-space: nowrap;
+        overflow: hidden;
+        text-overflow: ellipsis;
 
         i.fa {
           margin-right: 5px;
@@ -99,12 +147,30 @@ $content-width: 840px;
   }
 
   .content-wrapper {
-    flex: 2 1 $content-width;
-    overflow: auto;
+    box-sizing: border-box;
+    width: 100%;
+    max-width: $content-width;
+    flex: 1 1 auto;
+  }
+
+  @media screen and (max-width: $content-width + $sidebar-width) {
+    .sidebar-wrapper--empty {
+      display: none;
+    }
+
+    .sidebar-wrapper {
+      width: $sidebar-width;
+      flex: 0 0 auto;
+    }
+  }
+
+  @media screen and (max-width: $no-columns-breakpoint) {
+    .sidebar-wrapper {
+      width: 100%;
+    }
   }
 
   .content {
-    max-width: $content-width;
     padding: 20px 15px;
     padding-top: 60px;
     padding-left: 25px;
@@ -123,6 +189,12 @@ $content-width: 840px;
       padding-bottom: 40px;
       border-bottom: 1px solid lighten($ui-base-color, 8%);
       margin-bottom: 40px;
+
+      @media screen and (max-width: $no-columns-breakpoint) {
+        border-bottom: 0;
+        padding-bottom: 0;
+        font-weight: 700;
+      }
     }
 
     h3 {
@@ -147,7 +219,7 @@ $content-width: 840px;
       font-size: 16px;
       color: $secondary-text-color;
       line-height: 28px;
-      font-weight: 400;
+      font-weight: 500;
     }
 
     .fields-group h6 {
@@ -176,7 +248,7 @@ $content-width: 840px;
 
     & > p {
       font-size: 14px;
-      line-height: 18px;
+      line-height: 21px;
       color: $secondary-text-color;
       margin-bottom: 20px;
 
@@ -208,20 +280,42 @@ $content-width: 840px;
 
   @media screen and (max-width: $no-columns-breakpoint) {
     display: block;
-    overflow-y: auto;
-    -webkit-overflow-scrolling: touch;
 
-    .sidebar-wrapper,
-    .content-wrapper {
-      flex: 0 0 auto;
-      height: auto;
-      overflow: initial;
+    .sidebar-wrapper {
+      min-height: 0;
     }
 
     .sidebar {
       width: 100%;
       padding: 0;
       height: auto;
+
+      &__toggle {
+        display: flex;
+      }
+
+      & > ul {
+        display: none;
+      }
+
+      ul a,
+      ul ul a {
+        border-radius: 0;
+        border-bottom: 1px solid lighten($ui-base-color, 4%);
+        transition: none;
+
+        &:hover {
+          transition: none;
+        }
+      }
+
+      ul ul {
+        border-radius: 0;
+      }
+
+      ul .simple-navigation-active-leaf a {
+        border-bottom-color: $ui-highlight-color;
+      }
     }
   }
 }
@@ -270,10 +364,10 @@ body,
 
   .filter-subset {
     flex: 0 0 auto;
-    margin: 0 40px 10px 0;
+    margin: 0 40px 20px 0;
 
     &:last-child {
-      margin-bottom: 20px;
+      margin-bottom: 30px;
     }
 
     ul {