src/components/App.tsx

@@ -49,7 +49,7 @@ function SignedInHome({ person, onSignedOut }: { person: Person; onSignedOut: ()
     <AppShell
       person={person}
       search={<ExpertSearch />}
-      feed={<Feed feedUserId={person.feedUserId} person={person} onSignedOut={onSignedOut} featuredExperts={discover?.featuredExperts} />}
+      feed={<Feed feedUserId={person.feedUserId} person={person} onSignedOut={onSignedOut} featuredExperts={discover?.featuredExperts} trendingMinnects={discover?.trendingMinnects} searchPanel={<ExpertSearch />} />}
       discover={<DiscoverRailsView data={discover} />}
     />
   );

src/components/AppShell.tsx

@@ -96,11 +96,11 @@ export function AppShell({ person, search, feed, discover }: AppShellProps) {
       <main className="bento">
         <div className="bento-col bento-left">
           <AccountPanel person={person} />
-          {search}
+          {compact ? null : search}
         </div>
         <div className="bento-col bento-center">{feed}</div>
         <aside className="bento-col bento-right" aria-label="Discover">
-          {discover}
+          {compact ? null : discover}
         </aside>
       </main>
     </div>

src/components/Buttons.tsx

@@ -147,14 +147,17 @@ export interface DepthButtonProps extends NativeButton {
   label: string;
   sublabel?: string;
   icon?: ReactNode;
+  /** Raw leading content in place of the icon tile, for example a stack of avatars. */
+  leading?: ReactNode;
   /** Trailing content, for example a chevron or the current theme name. */
   trailing?: ReactNode;
 }
 
-export function DepthButton({ label, sublabel, icon, trailing, className, type = "button", ...rest }: DepthButtonProps) {
+export function DepthButton({ label, sublabel, icon, leading, trailing, className, type = "button", ...rest }: DepthButtonProps) {
   return (
     <button {...rest} type={type} className={cx("btn-depth", className)}>
-      {icon ? (
+      {leading ?? null}
+      {!leading && icon ? (
         <span className="btn-depth-icon" aria-hidden="true">
           {icon}
         </span>

src/components/DiscoverSheet.tsx

@@ -0,0 +1,148 @@
+"use client";
+
+// Mobile Discover sheet (spec "Sheets"): three soft depth rows that open the
+// Featured experts, Trending minnects and Find experts panels as 80% height
+// sheets, then the Dark/Light appearance switch. Styles: src/styles/sheet.css.
+import type { ReactNode } from "react";
+import type { DiscoverExpert, DiscoverMinnect } from "@/lib/discover";
+import { useTheme } from "@/lib/use-theme";
+import type { Theme } from "@/lib/theme";
+import { BottomSheet } from "./BottomSheet";
+import { DepthButton } from "./Buttons";
+import { FeaturedCarousel } from "./FeaturedCarousel";
+import { HexAvatar } from "./HexAvatar";
+import { TrendingMinnectsRail } from "./TrendingMinnectsRail";
+
+export type DiscoverPanel = "featured" | "trending" | "search";
+
+/** Width of the center photo in the featured panel sheet. */
+export const PANEL_CAROUSEL_SIZE = 150;
+
+/** "Name1, Name2 and N more" for the Featured experts row; shorter lists read plainly. */
+export function featuredSubtitle(experts: Pick<DiscoverExpert, "displayName">[]): string {
+  const names = experts.map((e) => e.displayName || "Expert");
+  if (names.length === 0) return "";
+  if (names.length === 1) return names[0];
+  if (names.length === 2) return `${names[0]} and ${names[1]}`;
+  return `${names[0]}, ${names[1]} and ${names.length - 2} more`;
+}
+
+function Chevron() {
+  return (
+    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true" className="btn-depth-chev">
+      <path d="m9 6 6 6-6 6" />
+    </svg>
+  );
+}
+
+const icon = { viewBox: "0 0 24 24", fill: "none", stroke: "currentColor", strokeWidth: 1.7, strokeLinecap: "round", strokeLinejoin: "round" } as const;
+
+function FlameIcon() {
+  return (
+    <svg {...icon}>
+      <path d="M12 21c4 0 7-2.8 7-6.8 0-4.5-4-6.7-5-11.2-2.3 1.7-3.5 4-3.2 6.5C9.5 9 8.6 8 8.3 6.6 6.3 8.5 5 10.9 5 14.2 5 18.2 8 21 12 21z" />
+    </svg>
+  );
+}
+
+function SearchIcon() {
+  return (
+    <svg {...icon}>
+      <circle cx="11" cy="11" r="7" />
+      <path d="m20 20-3.5-3.5" />
+    </svg>
+  );
+}
+
+function MoonIcon() {
+  return (
+    <svg {...icon} aria-hidden="true">
+      <path d="M20.5 14.5A8.5 8.5 0 0 1 9.5 3.5a8.5 8.5 0 1 0 11 11z" />
+    </svg>
+  );
+}
+
+function SunIcon() {
+  return (
+    <svg {...icon} aria-hidden="true">
+      <circle cx="12" cy="12" r="4" />
+      <path d="M12 2v2M12 20v2M4.9 4.9l1.4 1.4M17.7 17.7l1.4 1.4M2 12h2M20 12h2M4.9 19.1l1.4-1.4M17.7 6.3l1.4-1.4" />
+    </svg>
+  );
+}
+
+/** The Dark/Light switch in the soft depth style; the choice persists through useTheme. */
+export function AppearanceSwitch() {
+  const { theme, setTheme } = useTheme();
+  const options: { value: Theme; label: string; icon: ReactNode }[] = [
+    { value: "dark", label: "Dark", icon: <MoonIcon /> },
+    { value: "light", label: "Light", icon: <SunIcon /> },
+  ];
+  return (
+    <div className="seg-depth" role="group" aria-label="Appearance">
+      {options.map((o) => (
+        <button key={o.value} type="button" className={theme === o.value ? "on" : undefined} aria-pressed={theme === o.value} onClick={() => setTheme(o.value)}>
+          {o.icon}
+          {o.label}
+        </button>
+      ))}
+    </div>
+  );
+}
+
+export interface DiscoverSheetProps {
+  experts: DiscoverExpert[];
+  onOpen: (panel: DiscoverPanel) => void;
+  onClose: () => void;
+}
+
+export function DiscoverSheet({ experts, onOpen, onClose }: DiscoverSheetProps) {
+  return (
+    <BottomSheet title="Discover" onClose={onClose} className="sheet-discover">
+      {experts.length > 0 ? (
+        <DepthButton
+          label="Featured experts"
+          sublabel={featuredSubtitle(experts)}
+          onClick={() => onOpen("featured")}
+          leading={
+            <span className="depth-stack" aria-hidden="true">
+              {experts.slice(0, 3).map((e) => (
+                <HexAvatar key={String(e.id)} name={e.displayName || "Expert"} pictureUrl={e.pictureUrl} size="sm" />
+              ))}
+            </span>
+          }
+          trailing={<Chevron />}
+        />
+      ) : null}
+      <DepthButton label="Trending minnects" sublabel="Answers people are watching" icon={<FlameIcon />} trailing={<Chevron />} onClick={() => onOpen("trending")} />
+      <DepthButton label="Find experts" sublabel="Search by name, topic or category" icon={<SearchIcon />} trailing={<Chevron />} onClick={() => onOpen("search")} />
+      <span className="type-eyebrow sheet-sub">Appearance</span>
+      <AppearanceSwitch />
+    </BottomSheet>
+  );
+}
+
+export interface DiscoverPanelSheetProps {
+  panel: DiscoverPanel;
+  experts: DiscoverExpert[];
+  trending: DiscoverMinnect[];
+  search?: ReactNode;
+  onClose: () => void;
+}
+
+const TITLES: Record<DiscoverPanel, string> = {
+  featured: "Featured experts",
+  trending: "Trending minnects",
+  search: "Find experts",
+};
+
+/** One Discover panel as an 80% height sheet with a close button; reuses the desktop components. */
+export function DiscoverPanelSheet({ panel, experts, trending, search, onClose }: DiscoverPanelSheetProps) {
+  return (
+    <BottomSheet title={TITLES[panel]} onClose={onClose} className={`sheet-panel sheet-panel-${panel}`}>
+      {panel === "featured" ? <FeaturedCarousel experts={experts} size={PANEL_CAROUSEL_SIZE} variant="slide" /> : null}
+      {panel === "trending" ? <TrendingMinnectsRail minnects={trending} /> : null}
+      {panel === "search" ? search : null}
+    </BottomSheet>
+  );
+}

src/components/Feed.tsx

@@ -6,7 +6,8 @@ import { applyLikeOutcome, LikeError, sendLike } from "@/lib/like-client";
 import { firstLoadFailure, mergePosts, toCardPosts, upgradeVideos, type CardPost } from "@/lib/feed-model";
 import { PostError, publishAndConfirm } from "@/lib/post-client";
 import { DeleteError, sendDelete } from "@/lib/delete-client";
-import type { DiscoverExpert } from "@/lib/discover";
+import type { ReactNode } from "react";
+import type { DiscoverExpert, DiscoverMinnect } from "@/lib/discover";
 import type { ComposerProps } from "./Composer";
 import { FeedView, type FeedStatus } from "./FeedView";
 import { useCompactLayout } from "./layout-context";
@@ -18,6 +19,8 @@ export function Feed({
   feedUserId,
   person,
   featuredExperts,
+  trendingMinnects,
+  searchPanel,
 }: {
   onSignedOut: () => void;
   feedUserId?: string | null;
@@ -25,6 +28,9 @@ export function Feed({
   person?: ComposerProps["person"];
   /** Shown as a slide after the second post on phones. */
   featuredExperts?: DiscoverExpert[];
+  /** Phone Discover sheet: trending minnects and the Find experts panel. */
+  trendingMinnects?: DiscoverMinnect[];
+  searchPanel?: ReactNode;
 }) {
   const [posts, setPosts] = useState<CardPost[]>([]);
   const [status, setStatus] = useState<FeedStatus>("loading");
@@ -285,6 +291,8 @@ export function Feed({
       onSignedOut={onSignedOut}
       composer={{ value: draft, busy: posting, error: postFailed, file, onChange: changeDraft, onFile: changeFile, onSubmit: () => void publish(), person }}
       featuredExperts={featuredExperts}
+      trendingMinnects={trendingMinnects}
+      searchPanel={searchPanel}
       hasMore={!!nextCursor}
       sentinelRef={sentinel}
       listRef={list}

src/components/FeedView.tsx

@@ -2,7 +2,7 @@
 
 import type { ReactNode, Ref } from "react";
 import { canDelete, type CardPost } from "@/lib/feed-model";
-import type { DiscoverExpert } from "@/lib/discover";
+import type { DiscoverExpert, DiscoverMinnect } from "@/lib/discover";
 import { Composer, type ComposerProps } from "./Composer";
 import { GrowButton, IconButton } from "./Buttons";
 import { PostCard } from "./PostCard";
@@ -42,6 +42,10 @@ export interface FeedViewProps {
   hasMore?: boolean;
   /** Phone layout only: experts for the featured slide after the second post. */
   featuredExperts?: DiscoverExpert[];
+  /** Phone layout only: trending minnects for the Discover sheet. */
+  trendingMinnects?: DiscoverMinnect[];
+  /** Phone layout only: the Find experts panel shown in the Discover sheet. */
+  searchPanel?: ReactNode;
   /** Phone layout only: the slide on screen changed (for the dock). */
   onCurrentChange?: (slide: CurrentSlide) => void;
   /** Phone layout only: the dock's comments button, for the post on screen. */

src/components/MobileFeed.tsx

@@ -11,6 +11,7 @@ import { MobileDock } from "./MobileDock";
 import { BottomSheet } from "./BottomSheet";
 import { CommentsSection } from "./CommentsSection";
 import { Composer } from "./Composer";
+import { DiscoverPanelSheet, DiscoverSheet, type DiscoverPanel } from "./DiscoverSheet";
 import type { DiscoverExpert } from "@/lib/discover";
 import type { FeedViewProps } from "./FeedView";
 
@@ -281,8 +282,8 @@ function LoadSlide({ index, current, sentinelRef }: { index: number; current: bo
 export function MobileFeed(p: FeedViewProps) {
   const reel = useRef<HTMLDivElement | null>(null);
   const [current, setCurrent] = useState(0);
-  // The open sheet: the comments of one post, the composer, or none.
-  const [sheet, setSheet] = useState<{ kind: "comments"; postId: string } | { kind: "composer" } | null>(null);
+  // The open sheet: the comments of one post, the composer, Discover (more), one of its panels, or none.
+  const [sheet, setSheet] = useState<{ kind: "comments"; postId: string } | { kind: "composer" } | { kind: "more" } | { kind: "panel"; panel: DiscoverPanel } | null>(null);
   const closeSheet = useCallback(() => setSheet(null), []);
   // A successful post closes the composer: publishing ends with no error and an emptied draft.
   const wasBusy = useRef(false);
@@ -443,7 +444,10 @@ export function MobileFeed(p: FeedViewProps) {
             setSheet({ kind: "composer" });
             p.onOpenComposer?.();
           }}
-          onOpenMore={p.onOpenMore}
+          onOpenMore={() => {
+            setSheet({ kind: "more" });
+            p.onOpenMore?.();
+          }}
         />
       ) : null}
       {sheet?.kind === "comments" ? (
@@ -456,6 +460,12 @@ export function MobileFeed(p: FeedViewProps) {
           <Composer {...p.composer} />
         </BottomSheet>
       ) : null}
+      {sheet?.kind === "more" ? (
+        <DiscoverSheet experts={experts} onOpen={(panel) => setSheet({ kind: "panel", panel })} onClose={closeSheet} />
+      ) : null}
+      {sheet?.kind === "panel" ? (
+        <DiscoverPanelSheet panel={sheet.panel} experts={experts} trending={p.trendingMinnects ?? []} search={p.searchPanel} onClose={closeSheet} />
+      ) : null}
     </section>
   );
 }

src/dev/FeedPreview.tsx

@@ -126,6 +126,18 @@ export function FeedPreview() {
           loadingMore={loadingMore || paging}
           hasMore={hasMore}
           featuredExperts={FIXTURE_DISCOVER.featuredExperts}
+          trendingMinnects={FIXTURE_DISCOVER.trendingMinnects}
+          searchPanel={
+            <ExpertSearchView
+              query={query}
+              onQuery={setQuery}
+              categories={FIXTURE_CATEGORIES}
+              activeCategory={category}
+              onCategory={setCategory}
+              status="ready"
+              results={results}
+            />
+          }
           sentinelRef={sentinel}
           listRef={listRef}
           loadMoreFailed={false}

src/styles/sheet.css

@@ -88,6 +88,68 @@
 .sheet-composer .composer-emoji { left: 0; right: 0; width: auto; top: auto; bottom: 64px; }
 .sheet-composer .composer-att.composer-att-indent { margin-left: 0; }
 
+/* Discover sheet (More): soft depth rows, then the Appearance switch. */
+.sheet-discover { gap: 14px; }
+.sheet-discover .sheet-body { gap: 16px; padding: 4px 4px 4px; overflow-y: auto; }
+.sheet-discover .btn-depth { position: relative; overflow: hidden; isolation: isolate; min-height: 72px; }
+.sheet-discover .btn-depth-chev { width: 18px; height: 18px; flex: none; color: var(--ink-3); transition: color .3s; }
+.sheet-discover .btn-depth:hover .btn-depth-chev,
+.sheet-discover .btn-depth:focus-visible .btn-depth-chev { color: var(--on-accent); }
+.depth-stack { display: flex; flex: none; }
+.depth-stack .hex-avatar { margin-left: -10px; }
+.depth-stack .hex-avatar:first-child { margin-left: 0; }
+.sheet-sub { margin: 4px 0 -6px 4px; color: var(--ink-3); }
+.seg-depth {
+  display: flex;
+  gap: 4px;
+  padding: 4px;
+  border-radius: var(--r-card);
+  background: var(--bg);
+  box-shadow: inset 4px 4px 10px var(--neu-d), inset -4px -4px 10px var(--neu-l);
+}
+.seg-depth button {
+  appearance: none;
+  border: 0;
+  cursor: pointer;
+  flex: 1;
+  height: 44px;
+  border-radius: var(--r-ctl);
+  background: transparent;
+  color: var(--ink-3);
+  font-size: 14px;
+  font-weight: 700;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+  transition: background-color .25s, color .25s, box-shadow .25s;
+}
+.seg-depth button svg { width: 18px; height: 18px; }
+.seg-depth button.on {
+  background: var(--bg);
+  color: var(--ink);
+  box-shadow: 4px 4px 10px var(--neu-d), -4px -4px 10px var(--neu-l);
+}
+.seg-depth button:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
+
+/* Panel sheets: 80% height, the desktop panels without their tile chrome or repeated heading. */
+.sheet-panel { height: 80%; max-height: 80%; }
+.sheet-panel .sheet-body { flex: 1; overflow: hidden; }
+.sheet-panel .sheet-body > .tile {
+  flex: 1;
+  min-height: 0;
+  margin: 0;
+  padding: 0;
+  background: transparent;
+  box-shadow: none;
+  border-radius: 0;
+}
+.sheet-panel .sheet-body > .tile > .panel-head { display: none; }
+.sheet-panel .search-results,
+.sheet-panel .trend-list { flex: 1 1 0; min-height: 0; overflow-y: auto; }
+.sheet-panel .search-field input { font-size: 16px; }
+.sheet-panel-featured .sheet-body { overflow-y: auto; align-items: center; justify-content: center; }
+
 @media (prefers-reduced-motion: reduce) {
   .sheet, .sheet-bg { animation: none !important; }
 }

tests/discover-sheet.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+import { createElement } from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { readFileSync } from "node:fs";
+import { DiscoverPanelSheet, DiscoverSheet, featuredSubtitle, PANEL_CAROUSEL_SIZE } from "@/components/DiscoverSheet";
+import { FIXTURE_DISCOVER } from "@/dev/fixtures";
+
+const experts = FIXTURE_DISCOVER.featuredExperts;
+const html = (el: ReturnType<typeof createElement>) => renderToStaticMarkup(el);
+
+describe("featuredSubtitle", () => {
+  it("names two experts and counts the rest", () => {
+    const list = [{ displayName: "A" }, { displayName: "B" }, { displayName: "C" }, { displayName: "D" }];
+    expect(featuredSubtitle(list)).toBe("A, B and 2 more");
+    expect(featuredSubtitle(list.slice(0, 3))).toBe("A, B and 1 more");
+  });
+  it("reads plainly for short lists", () => {
+    expect(featuredSubtitle([])).toBe("");
+    expect(featuredSubtitle([{ displayName: "A" }])).toBe("A");
+    expect(featuredSubtitle([{ displayName: "A" }, { displayName: "B" }])).toBe("A and B");
+  });
+});
+
+describe("Discover sheet", () => {
+  const out = html(createElement(DiscoverSheet, { experts, onOpen: () => {}, onClose: () => {} }));
+  it("has three depth rows and the appearance switch", () => {
+    expect(out).toContain("Discover");
+    expect((out.match(/btn-depth"/g) ?? []).length).toBe(3);
+    expect(out).toContain("Featured experts");
+    expect(out).toContain("Trending minnects");
+    expect(out).toContain("Find experts");
+    expect(out).toContain('aria-label="Appearance"');
+    expect(out).toContain("Dark");
+    expect(out).toContain("Light");
+    expect(out).toContain(featuredSubtitle(experts));
+  });
+});
+
+describe("Discover panel sheets", () => {
+  it("shows the featured carousel at 150px", () => {
+    expect(PANEL_CAROUSEL_SIZE).toBe(150);
+    const out = html(createElement(DiscoverPanelSheet, { panel: "featured", experts, trending: [], onClose: () => {} }));
+    expect(out).toContain("--cfw:150px");
+    expect(out).toContain('aria-label="Close"');
+  });
+  it("is 80% high", () => {
+    const css = readFileSync("src/styles/sheet.css", "utf8");
+    expect(css).toMatch(/\.sheet-panel\s*\{[^}]*height:\s*80%/);
+  });
+});