Fix relationship manager on narrow screens (#10293)

At the cost of functionality

app/javascript/styles/mastodon/tables.scss

@@ -149,6 +149,10 @@ a.table-action-link {
           margin-top: 0;
         }
       }
+
+      @media screen and (max-width: $no-gap-breakpoint) {
+        display: none;
+      }
     }
 
     &__actions,
@@ -170,6 +174,10 @@ a.table-action-link {
       text-align: right;
       padding-right: 16px - 5px;
     }
+
+    @media screen and (max-width: $no-gap-breakpoint) {
+      display: none;
+    }
   }
 
   &__row {
@@ -177,6 +185,12 @@ a.table-action-link {
     border-top: 0;
     background: darken($ui-base-color, 4%);
 
+    @media screen and (max-width: $no-gap-breakpoint) {
+      &:first-child {
+        border-top: 1px solid darken($ui-base-color, 8%);
+      }
+    }
+
     &:hover {
       background: darken($ui-base-color, 2%);
     }
@@ -215,5 +229,15 @@ a.table-action-link {
     border: 1px solid darken($ui-base-color, 8%);
     border-top: 0;
     box-shadow: none;
+
+    @media screen and (max-width: $no-gap-breakpoint) {
+      border-top: 1px solid darken($ui-base-color, 8%);
+    }
+  }
+
+  @media screen and (max-width: 870px) {
+    .accounts-table tbody td.optional {
+      display: none;
+    }
   }
 }