fix: Shared documents with system in dark mode display partially on light background

closes #1300

shared/components/Branding.js

@@ -10,7 +10,7 @@ type Props = {
 function Branding({ href = process.env.URL }: Props) {
   return (
     <Link href={href}>
-      <OutlineLogo size={16} fill="#000" />&nbsp;Outline
+      <OutlineLogo size={16} />&nbsp;Outline
     </Link>
   );
 }
@@ -24,15 +24,17 @@ const Link = styled.a`
   font-size: 14px;
   text-decoration: none;
   border-top-right-radius: 2px;
-  color: ${props => props.theme.black};
+  color: ${props => props.theme.text};
   display: flex;
   align-items: center;
-  padding: 12px;
-  opacity: 0.8;
+  padding: 16px;
+
+  svg {
+    fill: ${props => props.theme.text};
+  }
 
   &:hover {
-    opacity: 1;
-    background: ${props => props.theme.smoke};
+    background: ${props => props.theme.sidebarBackground};
   }
 `;