Remove unecessary position relative rules

packages/website/ts/components/portal/portal.tsx

@@ -226,7 +226,7 @@ export class Portal extends React.Component<PortalProps, PortalState> {
                 ? TokenVisibility.UNTRACKED
                 : TokenVisibility.TRACKED;
         return (
-            <Container position="relative">
+            <Container>
                 <DocumentTitle title="0x Portal DApp" />
                 <TopBar
                     userAddress={this.props.userAddress}
@@ -327,7 +327,7 @@ export class Portal extends React.Component<PortalProps, PortalState> {
         const marginBottom = isMobile ? '200px' : '15px';
         return (
             <div>
-                <Container position="relative">
+                <Container>
                     {isMobile && <Container marginBottom="15px">{startOnboarding}</Container>}
                     <Container marginBottom={marginBottom}>
                         <Wallet

packages/website/ts/components/relayer_index/relayer_grid_tile.tsx

@@ -21,6 +21,8 @@ export interface RelayerGridTileProps {
 const styles: Styles = {
     root: {
         boxSizing: 'border-box',
+        // All material UI components have position: relative
+        // which creates a new stacking context and makes z-index stuff impossible. So reset.
         position: 'static',
     },
     innerDiv: {