Let page background shine through the footer

By visually separating it from other page content with an additional gradient background only when necessary.

src/room/InCallView.module.css

@@ -14,6 +14,23 @@ Please see LICENSE in the repository root for full details.
   overflow-y: auto;
 }
 
+/* Normally the footer uses a transparent background to allow our expressive
+page gradients to shine through. However, we sometimes need to visually separate
+it from the content underneath. If the call layout is overflowing, or if the
+spotlight tile is maximised and displaying video, apply a gradient background. */
+.overflowing > .footer,
+.fixedGrid:has(
+    > .tile[data-maximised="true"]
+      .spotlightItem[data-bg-style="transparent"][data-video-enabled="true"][aria-hidden="false"]
+  )
+  ~ .footer {
+  background: linear-gradient(
+    180deg,
+    rgba(0, 0, 0, 0) 0%,
+    var(--cpd-color-bg-canvas-default) 100%
+  );
+}
+
 .header {
   position: sticky;
   flex-shrink: 0;
@@ -82,19 +99,18 @@ Please see LICENSE in the repository root for full details.
   /* Disable pointer events so the overlay doesn't block interaction with
   elements behind it */
   pointer-events: none;
-}
 
-.fixedGrid > :not(:first-child),
-.scrollingGrid > :not(:first-child) {
-  pointer-events: initial;
+  > :not(:first-child) {
+    pointer-events: initial;
+  }
+
+  .tile {
+    position: absolute;
+    inset-block-start: 0;
+  }
 }
 
 .tile {
-  position: absolute;
-  inset-block-start: 0;
-}
-
-.tile.maximised {
   position: relative;
   flex-grow: 1;
 }

src/room/InCallView.tsx

@@ -259,6 +259,7 @@ export const InCallView: FC<InCallViewProps> = ({
   const reconnecting = useBehavior(vm.reconnecting$);
   const layout = useBehavior(vm.layout$);
   const edgeToEdge = useBehavior(vm.edgeToEdge$);
+  const overflowing = useBehavior(vm.overflowing$);
   const showNameTags = useBehavior(vm.showNameTags$);
   const showHeader = useBehavior(vm.showHeader$);
   const settingsOpen = useBehavior(vm.settingsOpen$);
@@ -468,6 +469,7 @@ export const InCallView: FC<InCallViewProps> = ({
             showRingingStatus={showRingingStatus}
             focusable={!contentObscured}
             className={classNames(className, styles.tile)}
+            itemClassName={styles.spotlightItem}
             style={style}
           />
         );
@@ -492,7 +494,9 @@ export const InCallView: FC<InCallViewProps> = ({
     if (layout.type === "pip") {
       return (
         <SpotlightTile
-          className={classNames(styles.tile, styles.maximised)}
+          className={styles.tile}
+          itemClassName={styles.spotlightItem}
+          data-maximised
           vm={layout.spotlight}
           expanded
           onToggleExpanded={null}
@@ -584,7 +588,7 @@ export const InCallView: FC<InCallViewProps> = ({
 
   // Only hide the settings button if we have an AppBar header and we are showing the header
   const footer = footerVm !== null && (
-    <CallFooter ref={footerRef} vm={footerVm} />
+    <CallFooter className={styles.footer} ref={footerRef} vm={footerVm} />
   );
   const allConnections = useBehavior(vm.allConnections$);
 
@@ -593,7 +597,9 @@ export const InCallView: FC<InCallViewProps> = ({
     // and the footer is also viewable by moving focus into it, so this is fine.
     // eslint-disable-next-line jsx-a11y/no-static-element-interactions
     <div
-      className={styles.inRoom}
+      className={classNames(styles.inRoom, {
+        [styles.overflowing]: overflowing,
+      })}
       ref={containerRef}
       onPointerUp={onViewPointerUp}
       onPointerMove={onPointerMove}

src/room/__snapshots__/InCallView.test.tsx.snap

@@ -164,7 +164,7 @@ exports[`InCallView > rendering > renders 1`] = `
       class="container"
     />
     <div
-      class="footer"
+      class="footer footer"
       data-testid="footer-container"
     >
       <div