diff --git a/src/lib/components/UnitFilter.svelte b/src/lib/components/UnitFilter.svelte
index 7fc2d09..89e5768 100644
--- a/src/lib/components/UnitFilter.svelte
+++ b/src/lib/components/UnitFilter.svelte
@@ -9,10 +9,10 @@
 
 	let {
 		units,
-		selectedUnitId = $bindable(""),
+		selectedUnitIds = $bindable([]),
 	}: {
 		units: UnitDoc[];
-		selectedUnitId?: string;
+		selectedUnitIds?: string[];
 	} = $props();
 
 	let pinnedIds = $state<string[]>([]);
@@ -41,6 +41,12 @@
 
 	const canPinMore = $derived(pinnedIds.length < MAX_PINS);
 
+	function toggleUnit(unitId: string) {
+		selectedUnitIds = selectedUnitIds.includes(unitId)
+			? selectedUnitIds.filter((id) => id !== unitId)
+			: [...selectedUnitIds, unitId];
+	}
+
 	async function togglePin(unit: UnitDoc) {
 		const token = getToken();
 		if (!token) {
@@ -84,20 +90,13 @@
 {/snippet}
 
 <div class="flex scrollbar-thin items-center gap-x-1 gap-y-2 overflow-x-scroll pb-2">
-	<button
-		type="button"
-		class="chip {selectedUnitId === '' ? 'chip-active' : ''}"
-		onclick={() => (selectedUnitId = "")}
-	>
-		All units
-	</button>
-
 	{#each pinnedUnits as unit (unit._id)}
 		<span class="inline-flex items-center">
 			<button
 				type="button"
-				class="chip {selectedUnitId === unit._id ? 'chip-active' : ''}"
-				onclick={() => (selectedUnitId = unit._id)}
+				class="chip {selectedUnitIds.includes(unit._id) ? 'chip-active' : ''}"
+				aria-pressed={selectedUnitIds.includes(unit._id)}
+				onclick={() => toggleUnit(unit._id)}
 			>
 				{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}
 			</button>
@@ -118,8 +117,9 @@
 		<span class="inline-flex items-center">
 			<button
 				type="button"
-				class="chip {selectedUnitId === unit._id ? 'chip-active' : ''}"
-				onclick={() => (selectedUnitId = unit._id)}
+				class="chip {selectedUnitIds.includes(unit._id) ? 'chip-active' : ''}"
+				aria-pressed={selectedUnitIds.includes(unit._id)}
+				onclick={() => toggleUnit(unit._id)}
 			>
 				{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}
 			</button>
diff --git a/src/lib/components/UnitRail.svelte b/src/lib/components/UnitRail.svelte
deleted file mode 100644
index af640a7..0000000
--- a/src/lib/components/UnitRail.svelte
+++ /dev/null
@@ -1,157 +0,0 @@
-<script lang="ts">
-	import { onMount } from "svelte";
-	import { query, mutation } from "$lib/api";
-	import { getToken, isAuthenticated, initAuth } from "$lib/stores/auth";
-	import { get } from "svelte/store";
-	import type { UnitDoc } from "$lib/types";
-
-	const MAX_PINS = 10;
-
-	let {
-		units,
-		selectedUnitId = $bindable(""),
-	}: {
-		units: UnitDoc[];
-		selectedUnitId?: string;
-	} = $props();
-
-	let pinnedIds = $state<string[]>([]);
-	let authed = $state(false);
-	let busy = $state(false);
-	let error = $state("");
-
-	onMount(async () => {
-		await initAuth();
-		if (!get(isAuthenticated)) return;
-		authed = true;
-		const token = getToken();
-		if (!token) return;
-		try {
-			pinnedIds = (await query("units:getPinned", { token })) as string[];
-			selectedUnitId =
-				units.find((unit) => pinnedIds.includes(unit._id))?._id ?? units[0]?._id ?? "";
-		} catch {
-			// ignore
-		}
-	});
-
-	const isPinned = (id: string) => pinnedIds.includes(id);
-	const canPinMore = $derived(pinnedIds.length < MAX_PINS);
-	const pinnedUnits = $derived(units.filter((u) => pinnedIds.includes(u._id)));
-	const unpinnedUnits = $derived(units.filter((u) => !pinnedIds.includes(u._id)));
-
-	async function togglePin(unit: UnitDoc) {
-		const token = getToken();
-		if (!token) {
-			error = "Sign in to pin units";
-			return;
-		}
-
-		busy = true;
-		error = "";
-		try {
-			const pinned = pinnedIds.includes(unit._id);
-			pinnedIds = (await mutation(pinned ? "units:unpin" : "units:pin", {
-				token,
-				unitId: unit._id,
-			})) as string[];
-		} catch (err: any) {
-			error = err?.message ?? "Failed to update pin";
-		} finally {
-			busy = false;
-		}
-	}
-</script>
-
-{#snippet pinIcon()}
-	<svg
-		width="14"
-		height="14"
-		viewBox="0 0 24 24"
-		fill="none"
-		stroke="currentColor"
-		stroke-width="2"
-		stroke-linecap="round"
-		stroke-linejoin="round"
-		aria-hidden="true"
-	>
-		<path d="M12 17v5"></path>
-		<path
-			d="M9 10.76a2 2 0 0 1-1.11 1.79l-1.78.9A2 2 0 0 0 5 15.24V16h14v-.76a2 2 0 0 0-1.11-1.79l-1.78-.9A2 2 0 0 1 15 10.76V6h1a2 2 0 0 0 0-4H8a2 2 0 0 0 0 4h1z"
-		></path>
-	</svg>
-{/snippet}
-
-<div class="unit-rail">
-	{#each pinnedUnits as unit (unit._id)}
-		<div class="unit-card {selectedUnitId === unit._id ? 'unit-card-active' : ''}">
-			<button
-				type="button"
-				class="flex h-full w-full flex-col items-start gap-1 text-left"
-				onclick={() => (selectedUnitId = unit._id)}
-				aria-label="Select {unit.code}"
-			>
-				<span class="text-ink font-serif text-base leading-tight"
-					>{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}</span
-				>
-				<span class="text-muted line-clamp-2 text-xs leading-snug">{unit.name}</span>
-			</button>
-			{#if authed}
-				<button
-					type="button"
-					class="pin-btn {isPinned(unit._id)
-						? 'pin-btn-active'
-						: ''} absolute top-1.5 right-1.5 z-10"
-					onclick={() => togglePin(unit)}
-					disabled={busy || (!isPinned(unit._id) && !canPinMore)}
-					title={isPinned(unit._id)
-						? "Unpin unit"
-						: canPinMore
-							? "Pin unit"
-							: "You can pin up to 10 units"}
-					aria-label={isPinned(unit._id) ? "Unpin unit" : "Pin unit"}
-				>
-					{@render pinIcon()}
-				</button>
-			{/if}
-		</div>
-	{/each}
-
-	{#each unpinnedUnits as unit (unit._id)}
-		<div class="unit-card {selectedUnitId === unit._id ? 'unit-card-active' : ''}">
-			<button
-				type="button"
-				class="flex h-full w-full flex-col items-start gap-1 text-left"
-				onclick={() => (selectedUnitId = unit._id)}
-				aria-label="Select {unit.code}"
-			>
-				<span class="text-ink font-serif text-base leading-tight"
-					>{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}</span
-				>
-				<span class="text-muted line-clamp-2 text-xs leading-snug">{unit.name}</span>
-			</button>
-			{#if authed}
-				<button
-					type="button"
-					class="pin-btn {isPinned(unit._id)
-						? 'pin-btn-active'
-						: ''} absolute top-1.5 right-1.5 z-10"
-					onclick={() => togglePin(unit)}
-					disabled={busy || (!isPinned(unit._id) && !canPinMore)}
-					title={isPinned(unit._id)
-						? "Unpin unit"
-						: canPinMore
-							? "Pin unit"
-							: "You can pin up to 10 units"}
-					aria-label={isPinned(unit._id) ? "Unpin unit" : "Pin unit"}
-				>
-					{@render pinIcon()}
-				</button>
-			{/if}
-		</div>
-	{/each}
-</div>
-
-{#if error}
-	<p class="text-primary mt-2 text-xs">{error}</p>
-{/if}
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index b791d17..beacf3b 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -1,22 +1,41 @@
 <script lang="ts">
 	import { query } from "$lib/api";
 	import { unitPath } from "$lib/paths";
+	import { getToken, initAuth, isAuthenticated } from "$lib/stores/auth";
 	import { onMount } from "svelte";
+	import { get } from "svelte/store";
 	import type { UnitDoc } from "$lib/types";
 
 	let units: UnitDoc[] = $state([]);
+	let pinnedUnits: UnitDoc[] = $state([]);
+	let authed = $state(false);
 	let loading = $state(true);
 	let error = $state("");
 
 	onMount(async () => {
 		try {
-			units = (await query("units:getAll")) as UnitDoc[];
+			await initAuth();
+			authed = get(isAuthenticated);
+			const token = getToken();
+			const [all, pinIds] = await Promise.all([
+				query("units:getAll") as Promise<UnitDoc[]>,
+				token
+					? (query("units:getPinned", { token }) as Promise<UnitDoc["_id"][]>)
+					: Promise.resolve([] as UnitDoc["_id"][]),
+			]);
+			units = all;
+			const unitMap = new Map(all.map((unit) => [unit._id, unit]));
+			pinnedUnits = pinIds
+				.map((id) => unitMap.get(id))
+				.filter((unit): unit is UnitDoc => !!unit);
 		} catch (err: any) {
 			error = err.message ?? "Failed to load units";
 		} finally {
 			loading = false;
 		}
 	});
+
+	const shownUnits = $derived(authed ? pinnedUnits : units);
 </script>
 
 <svelte:head>
@@ -42,14 +61,23 @@
 	</section>
 
 	<section class="border-rule border-t pt-10">
-		<p class="kicker mb-6">Units</p>
+		<div class="mb-6 flex items-end justify-between gap-4">
+			<p class="kicker">{authed ? "Pinned units" : "Units"}</p>
+			<a href="/units" class="nav-link">All units</a>
+		</div>
 		{#if loading}
 			<p class="kicker">Loading</p>
 		{:else if error}
 			<p class="kicker">{error}</p>
+		{:else if authed && pinnedUnits.length === 0}
+			<p class="text-muted text-sm">
+				Pin units from the
+				<a href="/units" class="text-secondary hover:text-secondary-dark">Units</a>
+				page to keep them here.
+			</p>
 		{:else}
 			<div class="unit-rail">
-				{#each units as unit}
+				{#each shownUnits as unit}
 					<a href={unitPath(unit.code)} class="unit-card group flex flex-col gap-1">
 						<span
 							class="text-ink group-hover:text-primary font-serif text-base leading-tight"
diff --git a/src/routes/layout.css b/src/routes/layout.css
index c9d3cfb..522cf3e 100644
--- a/src/routes/layout.css
+++ b/src/routes/layout.css
@@ -135,7 +135,7 @@ button {
 }
 
 .unit-rail {
-	@apply flex scrollbar-thin gap-3 overflow-x-scroll py-1 pb-2;
+	@apply flex scrollbar-thin gap-3 overflow-x-auto py-1 pb-2;
 }
 
 .unit-rail::-webkit-scrollbar {
@@ -143,7 +143,11 @@ button {
 }
 
 .unit-card {
-	@apply border-rule bg-surface hover:border-ink relative w-44 shrink-0 rounded-sm border p-3 transition-colors;
+	@apply border-rule bg-surface hover:border-ink relative min-w-0 rounded-sm border p-3 transition-colors;
+}
+
+.unit-rail .unit-card {
+	@apply w-44 shrink-0;
 }
 
 .unit-card-active {
diff --git a/src/routes/notes/+page.svelte b/src/routes/notes/+page.svelte
index 6eb70f8..97a53ff 100644
--- a/src/routes/notes/+page.svelte
+++ b/src/routes/notes/+page.svelte
@@ -10,7 +10,7 @@
 	let notes: (NoteDoc & { unit?: UnitDoc })[] = $state([]);
 	let units: UnitDoc[] = $state([]);
 	let loading = $state(true);
-	let selectedUnitId = $state("");
+	let selectedUnitIds: string[] = $state([]);
 	let sort = $state<"newest" | "top">("newest");
 	let searchQuery = $state("");
 
@@ -24,7 +24,10 @@
 
 	const visible = $derived.by(() => {
 		const q = searchQuery.trim().toLowerCase();
-		let list = selectedUnitId ? notes.filter((n) => n.unitId === selectedUnitId) : notes;
+		let list =
+			selectedUnitIds.length > 0
+				? notes.filter((n) => selectedUnitIds.includes(n.unitId))
+				: notes;
 		if (q) {
 			list = list.filter(
 				(n) => n.title.toLowerCase().includes(q) || n.content.toLowerCase().includes(q),
@@ -56,7 +59,7 @@
 	</div>
 
 	<div class="border-rule flex flex-wrap items-center justify-between gap-4 border-b py-4">
-		<UnitFilter bind:selectedUnitId {units} />
+		<UnitFilter bind:selectedUnitIds {units} />
 		<div class="flex gap-4">
 			<button
 				type="button"
diff --git a/src/routes/questions/+page.svelte b/src/routes/questions/+page.svelte
index 6ff1f80..cd7785b 100644
--- a/src/routes/questions/+page.svelte
+++ b/src/routes/questions/+page.svelte
@@ -10,7 +10,7 @@
 	let questions: (QuestionDoc & { unit?: UnitDoc })[] = $state([]);
 	let units: UnitDoc[] = $state([]);
 	let loading = $state(true);
-	let selectedUnitId = $state("");
+	let selectedUnitIds: string[] = $state([]);
 	let sort = $state<"newest" | "top">("newest");
 	let searchQuery = $state("");
 
@@ -27,8 +27,8 @@
 
 	const visible = $derived.by(() => {
 		const q = searchQuery.trim().toLowerCase();
-		let list = selectedUnitId
-			? questions.filter((q) => q.unitId === selectedUnitId)
+		let list = selectedUnitIds.length
+			? questions.filter((question) => selectedUnitIds.includes(question.unitId))
 			: questions;
 		if (q) {
 			list = list.filter(
@@ -63,7 +63,7 @@
 	</div>
 
 	<div class="border-rule flex flex-wrap items-center justify-between gap-4 border-b py-4">
-		<UnitFilter bind:selectedUnitId {units} />
+		<UnitFilter bind:selectedUnitIds {units} />
 		<div class="flex gap-4">
 			<button
 				type="button"
diff --git a/src/routes/units/+page.svelte b/src/routes/units/+page.svelte
index ed1bf99..d67b999 100644
--- a/src/routes/units/+page.svelte
+++ b/src/routes/units/+page.svelte
@@ -1,52 +1,19 @@
 <script lang="ts">
 	import { query } from "$lib/api";
+	import { unitPath } from "$lib/paths";
 	import { onMount } from "svelte";
-	import FeedRow from "$lib/components/FeedRow.svelte";
-	import UnitRail from "$lib/components/UnitRail.svelte";
-	import { postPath } from "$lib/paths";
-	import { timeAgo } from "$lib/time";
-	import type { NoteDoc, QuestionDoc, UnitDoc } from "$lib/types";
+	import type { UnitDoc } from "$lib/types";
 
 	let units: UnitDoc[] = $state([]);
-	let notes: NoteDoc[] = $state([]);
-	let questions: QuestionDoc[] = $state([]);
 	let loading = $state(true);
-	let contentLoading = $state(false);
-	let selectedUnitId = $state("");
-
-	const selectedUnit = $derived(units.find((u) => u._id === selectedUnitId) ?? null);
 
 	onMount(async () => {
 		try {
 			units = (await query("units:getAll")) as UnitDoc[];
-			selectedUnitId = units[0]?._id ?? "";
 		} finally {
 			loading = false;
 		}
 	});
-
-	$effect(() => {
-		loadContent(selectedUnitId);
-	});
-
-	async function loadContent(id: string) {
-		if (!id) {
-			notes = [];
-			questions = [];
-			return;
-		}
-		contentLoading = true;
-		try {
-			const [n, q] = await Promise.all([
-				query("notes:list", { unitId: id }),
-				query("questions:list", { unitId: id }),
-			]);
-			notes = n as NoteDoc[];
-			questions = q as QuestionDoc[];
-		} finally {
-			contentLoading = false;
-		}
-	}
 </script>
 
 <svelte:head>
@@ -63,92 +30,23 @@
 
 	{#if loading}
 		<p class="kicker py-16">Loading</p>
+	{:else if units.length === 0}
+		<p class="text-muted py-16 text-sm">No units yet.</p>
 	{:else}
-		<div class="border-rule border-b py-5">
-			<UnitRail {units} bind:selectedUnitId />
-		</div>
-
-		{#if selectedUnit}
-			<div class="pt-6">
-				<div class="flex flex-wrap items-baseline justify-between gap-x-4 gap-y-1">
-					<a
-						href={`/${selectedUnit.code}`}
-						class="text-ink hover:text-primary font-serif text-2xl font-medium"
+		<div class="grid grid-cols-1 gap-3 pt-6 sm:grid-cols-2 lg:grid-cols-3">
+			{#each units as unit (unit._id)}
+				<a href={unitPath(unit.code)} class="unit-card flex h-full w-full flex-col gap-2">
+					<span class="text-ink font-serif text-base leading-tight"
+						>{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}</span
 					>
-						{selectedUnit.code}{selectedUnit.code2 ? ` / ${selectedUnit.code2}` : ""}
-					</a>
-					<p class="text-muted text-sm">{selectedUnit.name}</p>
-				</div>
-				{#if selectedUnit.description}
-					<p class="text-muted mt-1 text-sm">
-						{selectedUnit.description}
-					</p>
-				{/if}
-
-				{#if contentLoading}
-					<p class="kicker py-16">Loading</p>
-				{:else}
-					{#if notes.length > 0}
-						<p class="kicker border-rule mt-8 border-t pt-8">Notes</p>
-						{#each notes as note}
-							<FeedRow
-								href={postPath(selectedUnit.code, note._id)}
-								title={note.title}
-								content={note.content}
-								unitCode={selectedUnit.code +
-									(selectedUnit.code2 ? ` / ${selectedUnit.code2}` : "")}
-								meta="{note.authorName} · {timeAgo(
-									note.createdAt,
-								)} · {note.commentCount} comment{note.commentCount === 1
-									? ''
-									: 's'}"
-								voteCount={note.voteCount}
-								targetType="note"
-								targetId={note._id}
-							/>
-						{/each}
+					<span class="text-ink text-sm leading-snug">{unit.name}</span>
+					{#if unit.description}
+						<p class="text-muted line-clamp-3 text-xs leading-snug">
+							{unit.description}
+						</p>
 					{/if}
-
-					{#if questions.length > 0}
-						<p class="kicker border-rule mt-8 border-t pt-8">Questions</p>
-						{#each questions as question}
-							<FeedRow
-								href={postPath(selectedUnit.code, question._id)}
-								title={question.title}
-								content={question.content}
-								unitCode={selectedUnit.code +
-									(selectedUnit.code2 ? ` / ${selectedUnit.code2}` : "")}
-								meta="{question.authorName} · {timeAgo(
-									question.createdAt,
-								)} · {question.answerCount} answer{question.answerCount === 1
-									? ''
-									: 's'}"
-								voteCount={question.voteCount}
-								targetType="question"
-								targetId={question._id}
-							/>
-						{/each}
-					{/if}
-
-					{#if notes.length === 0 && questions.length === 0}
-						<p class="text-muted mt-8 text-sm">No content for this unit yet.</p>
-						<div class="mt-4 flex gap-4">
-							<a
-								href="/post/note"
-								class="text-secondary hover:text-secondary-dark text-sm"
-								>Post a note</a
-							>
-							<a
-								href="/post/question"
-								class="text-secondary hover:text-secondary-dark text-sm"
-								>Ask a question</a
-							>
-						</div>
-					{/if}
-				{/if}
-			</div>
-		{:else}
-			<p class="text-muted py-16 text-sm">Select a unit to see its notes and questions.</p>
-		{/if}
+				</a>
+			{/each}
+		</div>
 	{/if}
 </div>