diff --git a/app/(app)/chats/[id]/page.tsx b/app/(app)/chats/[id]/page.tsx
index 9ba2d268..72a13118 100644
--- a/app/(app)/chats/[id]/page.tsx
+++ b/app/(app)/chats/[id]/page.tsx
@@ -35,6 +35,7 @@ import { toast } from "sonner";
 import { channelAuthorizer } from "@/lib/realtime";
 import { cn } from "@/lib/utils";
 import { useVisualViewport } from "@/lib/use-visual-viewport";
+import { ConfirmModal } from "@/components/ui/confirm-modal";
 import { useNotifications } from "@/components/notifications/notifications-provider";
 import {
   chat,
@@ -71,6 +72,9 @@ export default function ChatThreadPage() {
   const [replyTo, setReplyTo] = useState<ChatMessage | null>(null);
   const [menu, setMenu] = useState<{ message: ChatMessage; point: MenuPoint } | null>(null);
   const [forwarding, setForwarding] = useState<ChatMessage | null>(null);
+  // Non-null asks before deleting for everyone. Deleting only for yourself is
+  // reversible by the others still having it, so it goes straight through.
+  const [confirmDelete, setConfirmDelete] = useState<ChatMessage | null>(null);
   const [starredIds, setStarredIds] = useState<Set<string>>(new Set());
   // user id → when they last typed. Kept as timestamps rather than a boolean
   // so the indicator expires on its own: there is no "stopped typing" event,
@@ -295,12 +299,6 @@ export default function ChatThreadPage() {
 
   const deleteMessage = useCallback(
     async (m: ChatMessage, scope: "me" | "everyone") => {
-      if (
-        scope === "everyone" &&
-        !window.confirm("Delete this message for everyone?")
-      ) {
-        return;
-      }
       try {
         await chat.deleteMessage(id, m.id, scope);
         if (scope === "me") {
@@ -695,7 +693,8 @@ export default function ChatThreadPage() {
             // Only the sender may erase a message for everyone.
             onDeleteForEveryone:
               menu.message.sender_id === user.id
-                ? () => void deleteMessage(menu.message, "everyone")
+                ? // Ask first — the modal calls deleteMessage on confirm.
+                  () => setConfirmDelete(menu.message)
                 : undefined,
             // Reporting your own message is meaningless.
             onReport:
@@ -714,6 +713,17 @@ export default function ChatThreadPage() {
         />
       )}
 
+      <ConfirmModal
+        open={confirmDelete !== null}
+        onClose={() => setConfirmDelete(null)}
+        title="Delete for everyone?"
+        message="This removes the message from the conversation for all participants. It can't be undone."
+        confirmLabel="Delete"
+        onConfirm={async () => {
+          if (confirmDelete) await deleteMessage(confirmDelete, "everyone");
+        }}
+      />
+
       {forwarding && (
         <ForwardDialog
           message={forwarding}
diff --git a/components/chat/chat-composer.tsx b/components/chat/chat-composer.tsx
index 4312816c..baf54411 100644
--- a/components/chat/chat-composer.tsx
+++ b/components/chat/chat-composer.tsx
@@ -13,13 +13,16 @@
  */
 
 import { useCallback, useEffect, useRef, useState } from "react";
-import { Paperclip, Smile, SendHorizonal, X } from "lucide-react";
+import { Paperclip, Sticker, SendHorizonal, X } from "lucide-react";
 import { LinkPreviewCard } from "@/components/chat/link-preview-card";
 import {
   ComposerAttachments,
   type StagedAttachment,
 } from "@/components/chat/composer-attachments";
-import { StickerPicker } from "@/components/chat/sticker-picker";
+import {
+  StickerPicker,
+  type StickerAnchor,
+} from "@/components/chat/sticker-picker";
 import { compressImage } from "@/lib/compress-image";
 import { cn } from "@/lib/utils";
 import {
@@ -70,7 +73,9 @@ export function ChatComposer({
   const [staged, setStaged] = useState<StagedAttachment[]>([]);
   const ref = useRef<HTMLTextAreaElement>(null);
   const fileRef = useRef<HTMLInputElement>(null);
-  const [pickingSticker, setPickingSticker] = useState(false);
+  // Non-null opens the sticker picker AND positions it: the popover hangs
+  // off the button's viewport rect, which only exists at click time.
+  const [stickerAnchor, setStickerAnchor] = useState<StickerAnchor | null>(null);
   const lookupSeq = useRef(0);
 
   // Grow with the content, up to a cap.
@@ -248,61 +253,84 @@ export function ChatComposer({
             e.target.value = "";
           }}
         />
-        <button
-          type="button"
-          onClick={() => fileRef.current?.click()}
-          disabled={disabled}
-          aria-label="Attach a file"
-          className="inline-flex size-9 shrink-0 items-center justify-center rounded-full text-muted-foreground hover:text-foreground disabled:opacity-40"
-        >
-          <Paperclip className="size-4" />
-        </button>
-        <button
-          type="button"
-          onClick={() => setPickingSticker(true)}
-          disabled={disabled}
-          aria-label="Send a sticker"
-          className="inline-flex size-9 shrink-0 items-center justify-center rounded-full text-muted-foreground hover:text-foreground disabled:opacity-40"
-        >
-          <Smile className="size-4" />
-        </button>
-
-        <textarea
-          ref={ref}
-          rows={1}
-          value={value}
-          disabled={disabled}
-          placeholder={placeholder}
-          onChange={(e) => {
-            setValue(e.target.value);
-            // Fired on every keystroke; the handler throttles itself, so the
-            // thread hears "still typing" every few seconds rather than per
-            // character.
-            onTyping?.();
-          }}
-          onKeyDown={(e) => {
-            // Enter sends on a physical keyboard; Shift+Enter makes a newline.
-            // On touch keyboards Enter must insert a newline instead — there is
-            // no Shift to reach for — so the send button is the only way there.
-            if (e.key !== "Enter" || e.shiftKey) return;
-            const touch =
-              typeof window !== "undefined" &&
-              window.matchMedia("(pointer: coarse)").matches;
-            if (touch) return;
-            e.preventDefault();
-            submit();
-          }}
+        {/* One field group: attach on the left, sticker on the right, the
+            text between them. The border and background live here rather than
+            on the textarea so all three read as a single control, and
+            focus-within moves the ring to the group. */}
+        <div
           className={cn(
-            // 16px on touch devices: iOS Safari zooms the whole page when a
-            // focused field computes below that, which on a composer means the
-            // thread jumps every time the keyboard opens. Pointer-based devices
-            // keep the app's 14px chrome.
-            "flex-1 resize-none rounded-2xl border border-border bg-muted/40 px-3 py-2",
-            "text-sm pointer-coarse:text-base",
-            "placeholder:text-muted-foreground focus:outline-none focus:ring-1 focus:ring-primary/40",
-            "disabled:opacity-60",
+            // Minimal horizontal padding: the icon buttons keep a full-height
+            // tap target, but sit close to the group's edges and to the text
+            // rather than floating in their own gutters.
+            "flex flex-1 items-end gap-0.5 rounded-2xl border border-border bg-muted/40 px-1 py-1",
+            "focus-within:ring-1 focus-within:ring-primary/40",
+            disabled && "opacity-60",
           )}
-        />
+        >
+          <button
+            type="button"
+            onClick={() => fileRef.current?.click()}
+            disabled={disabled}
+            aria-label="Attach a file"
+            className="inline-flex h-8 w-8 mr-1 shrink-0 items-center justify-center rounded-full text-muted-foreground hover:text-foreground disabled:opacity-40"
+          >
+            <Paperclip className="size-5" />
+          </button>
+
+          <textarea
+            ref={ref}
+            rows={1}
+            value={value}
+            disabled={disabled}
+            placeholder={placeholder}
+            onChange={(e) => {
+              setValue(e.target.value);
+              // Fired on every keystroke; the handler throttles itself, so the
+              // thread hears "still typing" every few seconds rather than per
+              // character.
+              onTyping?.();
+            }}
+            onKeyDown={(e) => {
+              // Enter sends on a physical keyboard; Shift+Enter makes a
+              // newline. On touch keyboards Enter must insert a newline
+              // instead — there is no Shift to reach for — so the send button
+              // is the only way there.
+              if (e.key !== "Enter" || e.shiftKey) return;
+              const touch =
+                typeof window !== "undefined" &&
+                window.matchMedia("(pointer: coarse)").matches;
+              if (touch) return;
+              e.preventDefault();
+              submit();
+            }}
+            className={cn(
+              // Bare: the group above owns the frame. Only the type size and
+              // the growth behaviour belong to the field itself.
+              "min-w-0 flex-1 resize-none bg-transparent py-1.5",
+              // 16px on touch devices: iOS Safari zooms the whole page when a
+              // focused field computes below that, which on a composer means
+              // the thread jumps every time the keyboard opens. Pointer-based
+              // devices keep the app's 14px chrome.
+              "text-sm pointer-coarse:text-base",
+              "placeholder:text-muted-foreground focus:outline-none",
+              "disabled:opacity-60",
+            )}
+          />
+
+          <button
+            type="button"
+            onClick={(e) => {
+              const r = e.currentTarget.getBoundingClientRect();
+              // Top-centre of the button: the popover opens upward from here.
+              setStickerAnchor({ x: r.left + r.width / 2, y: r.top });
+            }}
+            disabled={disabled}
+            aria-label="Send a sticker"
+            className="inline-flex h-8 w-8 shrink-0 items-center justify-center rounded-full text-muted-foreground hover:text-foreground disabled:opacity-40"
+          >
+            <Sticker className="size-5" />
+          </button>
+        </div>
         <button
           type="button"
           onClick={submit}
@@ -317,13 +345,14 @@ export function ChatComposer({
         </button>
       </div>
 
-      {pickingSticker && (
+      {stickerAnchor && (
         <StickerPicker
+          anchor={stickerAnchor}
           // Sent on its own, with no text: a sticker IS the message.
           onPick={(sticker) =>
             onSend("", undefined, undefined, undefined, sticker.key)
           }
-          onClose={() => setPickingSticker(false)}
+          onClose={() => setStickerAnchor(null)}
         />
       )}
     </div>
diff --git a/components/chat/chat-profile-header.tsx b/components/chat/chat-profile-header.tsx
index b7142112..dfc45fee 100644
--- a/components/chat/chat-profile-header.tsx
+++ b/components/chat/chat-profile-header.tsx
@@ -15,6 +15,7 @@ import { useState } from "react";
 import { BellOff, Bell, ShieldBan, ShieldCheck } from "lucide-react";
 import { toast } from "sonner";
 import { Button } from "@/components/ui/button";
+import { ConfirmModal } from "@/components/ui/confirm-modal";
 import { relationships } from "@/lib/social";
 import {
   chat,
@@ -44,6 +45,9 @@ export function ChatProfileHeader({
   onChanged: () => void;
 }) {
   const [busy, setBusy] = useState(false);
+  // Blocking asks first; unblocking is immediate, since it only restores what
+  // was there before.
+  const [confirmBlock, setConfirmBlock] = useState(false);
   const rel = detail.relationship;
   const peer = detail.peer;
   const muted = isMuted(detail);
@@ -64,9 +68,6 @@ export function ChatProfileHeader({
   const toggleBlock = async () => {
     if (!peer) return;
     const blocking = !rel?.blocked;
-    if (blocking && !window.confirm(`Block ${peer.name}? They won't be able to message you.`)) {
-      return;
-    }
     setBusy(true);
     try {
       if (blocking) await relationships.block(peer.handle);
@@ -134,7 +135,9 @@ export function ChatProfileHeader({
             variant={rel?.blocked ? "outline" : "destructive"}
             size="sm"
             disabled={busy}
-            onClick={toggleBlock}
+            onClick={() =>
+              rel?.blocked ? void toggleBlock() : setConfirmBlock(true)
+            }
           >
             {rel?.blocked ? (
               <>
@@ -148,6 +151,14 @@ export function ChatProfileHeader({
           </Button>
         )}
       </div>
+      <ConfirmModal
+        open={confirmBlock}
+        onClose={() => setConfirmBlock(false)}
+        title={`Block ${peer?.name ?? "this person"}?`}
+        message="They won't be able to message you, and you won't see their messages. You can unblock them here later."
+        confirmLabel="Block"
+        onConfirm={toggleBlock}
+      />
     </div>
   );
 }
diff --git a/components/chat/group-members-tab.tsx b/components/chat/group-members-tab.tsx
index 8b9ce9dc..7d740495 100644
--- a/components/chat/group-members-tab.tsx
+++ b/components/chat/group-members-tab.tsx
@@ -14,6 +14,7 @@ import { toast } from "sonner";
 import { UserAvatar } from "@/components/ui/user-avatar";
 import { Button } from "@/components/ui/button";
 import { AddMembersDialog } from "@/components/chat/add-members-dialog";
+import { ConfirmModal } from "@/components/ui/confirm-modal";
 import { chat, isGroupAdmin, type ConversationDetail } from "@/lib/chat";
 
 const ROLE_LABEL: Record<string, string> = {
@@ -34,6 +35,9 @@ export function GroupMembersTab({
   onChanged: () => void;
 }) {
   const [busy, setBusy] = useState<string | null>(null);
+  // The member being removed. Non-null asks first.
+  const [confirmRemove, setConfirmRemove] =
+    useState<ConversationDetail["participants"][number] | null>(null);
   const [adding, setAdding] = useState(false);
   const iAmAdmin = isGroupAdmin(detail.my_role);
   const iAmOwner = detail.my_role === "owner";
@@ -132,14 +136,8 @@ export function GroupMembersTab({
                   type="button"
                   disabled={busy === m.handle}
                   aria-label={`Remove ${m.name}`}
-                  onClick={() => {
-                    if (!window.confirm(`Remove ${m.name} from the group?`)) return;
-                    void act(
-                      m.handle,
-                      () => chat.removeMember(conversationId, m.handle),
-                      `${m.name} was removed`,
-                    );
-                  }}
+                  // Ask first — the modal calls act() on confirm.
+                  onClick={() => setConfirmRemove(m)}
                   className="shrink-0 rounded-md p-1.5 text-destructive hover:opacity-80 disabled:opacity-40"
                 >
                   <UserMinus className="size-4" />
@@ -158,6 +156,21 @@ export function GroupMembersTab({
           onAdded={onChanged}
         />
       )}
+      <ConfirmModal
+        open={confirmRemove !== null}
+        onClose={() => setConfirmRemove(null)}
+        title={`Remove ${confirmRemove?.name ?? "this member"}?`}
+        message="They'll lose access to the conversation and its history from here on."
+        confirmLabel="Remove"
+        onConfirm={async () => {
+          if (!confirmRemove) return;
+          await act(
+            confirmRemove.handle,
+            () => chat.removeMember(conversationId, confirmRemove.handle),
+            `${confirmRemove.name} was removed`,
+          );
+        }}
+      />
     </div>
   );
 }
diff --git a/components/chat/group-settings-tab.tsx b/components/chat/group-settings-tab.tsx
index 92689c5a..874f2525 100644
--- a/components/chat/group-settings-tab.tsx
+++ b/components/chat/group-settings-tab.tsx
@@ -13,6 +13,7 @@ import { toast } from "sonner";
 import { useRouter } from "next/navigation";
 import { Button } from "@/components/ui/button";
 import { UserAvatar } from "@/components/ui/user-avatar";
+import { ConfirmModal } from "@/components/ui/confirm-modal";
 import { compressImage } from "@/lib/compress-image";
 import {
   chat,
@@ -38,6 +39,7 @@ export function GroupSettingsTab({
   const router = useRouter();
   const [title, setTitle] = useState(detail.title ?? "");
   const [busy, setBusy] = useState(false);
+  const [confirmLeave, setConfirmLeave] = useState(false);
   const [uploading, setUploading] = useState(false);
   const fileRef = useRef<HTMLInputElement>(null);
   const iAmAdmin = isGroupAdmin(detail.my_role);
@@ -96,15 +98,6 @@ export function GroupSettingsTab({
   };
 
   const leave = async () => {
-    if (
-      !window.confirm(
-        detail.my_role === "owner"
-          ? "Leave this group? Another admin will become the owner."
-          : "Leave this group?",
-      )
-    ) {
-      return;
-    }
     setBusy(true);
     try {
       await chat.removeMember(conversationId, selfHandle);
@@ -219,7 +212,7 @@ export function GroupSettingsTab({
           variant="destructive"
           size="sm"
           disabled={busy}
-          onClick={leave}
+          onClick={() => setConfirmLeave(true)}
         >
           <LogOut className="size-4" /> Leave group
         </Button>
@@ -230,6 +223,18 @@ export function GroupSettingsTab({
           </p>
         )}
       </section>
+      <ConfirmModal
+        open={confirmLeave}
+        onClose={() => setConfirmLeave(false)}
+        title="Leave this group?"
+        message={
+          detail.my_role === "owner"
+            ? "You own this group. The longest-serving admin becomes the owner in your place."
+            : "You'll stop receiving messages from this conversation."
+        }
+        confirmLabel="Leave"
+        onConfirm={leave}
+      />
     </div>
   );
 }
diff --git a/components/chat/message-group.tsx b/components/chat/message-group.tsx
index bb6a410d..25501fbc 100644
--- a/components/chat/message-group.tsx
+++ b/components/chat/message-group.tsx
@@ -316,43 +316,53 @@ export function MessageGroup({
             </div>
 
             {m.reactions?.length > 0 && (
-              <button
-                type="button"
-                // ONE control, not one per emoji. Two different jobs depending
-                // on whether you are in the reaction list already: if you have
-                // reacted, this retracts it; if you have not, it opens the
-                // list of who reacted. Per-chip toggling would make "see who
-                // reacted" unreachable for anyone who had.
-                onClick={() => onTrailClick(m)}
-                aria-label={
-                  m.reactions.some((r) => r.mine)
-                    ? "Remove your reaction"
-                    : "See who reacted"
-                }
+              // Aligned like the bubble it belongs to. The gesture wrapper is
+              // full-width, so without this the trail sits at the left edge
+              // while your own bubble is over on the right.
+              <div
                 className={cn(
-                  "-mt-1 inline-flex items-center gap-0.5 rounded-full border bg-background px-1.5 py-0.5 text-xs",
-                  mine ? "self-end mr-1" : "self-start ml-1",
-                  m.reactions.some((r) => r.mine)
-                    ? "border-primary/40 bg-primary/10"
-                    : "border-border",
+                  "flex w-full",
+                  mine ? "justify-end" : "justify-start",
                 )}
               >
-                {m.reactions.slice(0, MAX_TRAIL_EMOJI).map((r) => (
-                  <span key={r.emoji}>{r.emoji}</span>
-                ))}
-                {m.reactions.length > MAX_TRAIL_EMOJI && (
-                  <span className="tabular-nums text-muted-foreground">
-                    +{m.reactions.length - MAX_TRAIL_EMOJI}
-                  </span>
-                )}
-                {/* Total people, not distinct emoji — "😂❤️ 5" reads as five
+                <button
+                  type="button"
+                  // ONE control, not one per emoji. Two different jobs depending
+                  // on whether you are in the reaction list already: if you have
+                  // reacted, this retracts it; if you have not, it opens the
+                  // list of who reacted. Per-chip toggling would make "see who
+                  // reacted" unreachable for anyone who had.
+                  onClick={() => onTrailClick(m)}
+                  aria-label={
+                    m.reactions.some((r) => r.mine)
+                      ? "Remove your reaction"
+                      : "See who reacted"
+                  }
+                  className={cn(
+                    "-mt-1 inline-flex items-center gap-0.5 rounded-full border bg-background px-1.5 py-0.5 text-xs",
+                    mine ? "mr-1" : "ml-1",
+                    m.reactions.some((r) => r.mine)
+                      ? "border-primary/40 bg-primary/10"
+                      : "border-border",
+                  )}
+                >
+                  {m.reactions.slice(0, MAX_TRAIL_EMOJI).map((r) => (
+                    <span key={r.emoji}>{r.emoji}</span>
+                  ))}
+                  {m.reactions.length > MAX_TRAIL_EMOJI && (
+                    <span className="tabular-nums text-muted-foreground">
+                      +{m.reactions.length - MAX_TRAIL_EMOJI}
+                    </span>
+                  )}
+                  {/* Total people, not distinct emoji — "😂❤️ 5" reads as five
                     reactions, which is what it is. */}
-                {totalReactions(m) > 1 && (
-                  <span className="ml-0.5 tabular-nums text-muted-foreground">
-                    {totalReactions(m)}
-                  </span>
-                )}
-              </button>
+                  {totalReactions(m) > 1 && (
+                    <span className="ml-0.5 tabular-nums text-muted-foreground">
+                      {totalReactions(m)}
+                    </span>
+                  )}
+                </button>
+              </div>
             )}
           </MessageGestures>
         ))}
diff --git a/components/chat/reaction-row.tsx b/components/chat/reaction-row.tsx
index 8242b24f..8822f255 100644
--- a/components/chat/reaction-row.tsx
+++ b/components/chat/reaction-row.tsx
@@ -4,20 +4,33 @@
  * The emoji row at the top of a message's long-press menu.
  *
  * Five quick reactions plus a "+" that opens the full set — a drawer on
- * mobile, a modal on desktop, reusing ResponsiveDialog so it behaves like
- * every other chat surface.
+ * mobile, a popover anchored to the "+" on desktop. A modal would take over
+ * the screen and hide the message being reacted to, which is the one thing
+ * that needs to stay visible while choosing.
  *
  * It sits inside the context menu rather than being its own popover: long
  * press is one gesture, and two surfaces competing for it would mean neither
  * felt reliable.
  */
 
-import { useState } from "react";
+import { useEffect, useState } from "react";
+import { createPortal } from "react-dom";
 import { Plus } from "lucide-react";
 import { EMOJI_GROUPS } from "@/components/ui/emoji-picker";
-import { ResponsiveDialog } from "@/components/chat/responsive-dialog";
+import { useMediaQuery } from "@/components/selection-toolbar/shared";
+import {
+  Drawer,
+  DrawerContent,
+  DrawerDescription,
+  DrawerHeader,
+  DrawerTitle,
+} from "@/components/ui/drawer";
 import { cn } from "@/lib/utils";
 
+const POPOVER_W = 320;
+const POPOVER_H = 320;
+const EDGE_PAD = 8;
+
 /** What a double-tap sends. Matches the server's own default. */
 export const HEART_EMOJI = "❤️";
 
@@ -33,7 +46,12 @@ export function ReactionRow({
   /** Picking the current emoji again clears it — the caller decides. */
   onPick: (emoji: string) => void;
 }) {
-  const [browsing, setBrowsing] = useState(false);
+  // Non-null both opens the full set and positions it: the popover hangs off
+  // the "+" button's rect, which only exists at click time.
+  const [browsing, setBrowsing] = useState<{ x: number; y: number } | null>(
+    null,
+  );
+  const close = () => setBrowsing(null);
 
   return (
     <>
@@ -55,7 +73,11 @@ export function ReactionRow({
         ))}
         <button
           type="button"
-          onClick={() => setBrowsing(true)}
+          onClick={(e) => {
+            const r = e.currentTarget.getBoundingClientRect();
+            // Top-centre of the "+": the popover opens upward from here.
+            setBrowsing({ x: r.left + r.width / 2, y: r.top });
+          }}
           aria-label="More reactions"
           className="inline-flex size-9 items-center justify-center rounded-full text-muted-foreground hover:bg-muted hover:text-foreground"
         >
@@ -63,39 +85,118 @@ export function ReactionRow({
         </button>
       </div>
 
-      {browsing && (
-        <ResponsiveDialog
-          title="Pick a reaction"
-          description="Choose any emoji to react with."
-          onClose={() => setBrowsing(false)}
-        >
-          <div className="space-y-4 p-4">
-            {EMOJI_GROUPS.map((group) => (
-              <section key={group.label}>
-                <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-muted-foreground">
-                  {group.label}
-                </h3>
-                <div className="grid grid-cols-8 gap-1">
-                  {group.emojis.map((emoji) => (
-                    <button
-                      key={emoji}
-                      type="button"
-                      onClick={() => {
-                        setBrowsing(false);
-                        onPick(emoji);
-                      }}
-                      aria-label={`React ${emoji}`}
-                      className="inline-flex size-9 items-center justify-center rounded-md text-lg hover:bg-muted"
-                    >
-                      {emoji}
-                    </button>
-                  ))}
-                </div>
-              </section>
-            ))}
-          </div>
-        </ResponsiveDialog>
-      )}
+      {browsing && <FullSet anchor={browsing} onPick={onPick} onClose={close} />}
     </>
   );
 }
+
+/** The whole emoji set: popover on desktop, drawer on touch. */
+function FullSet({
+  anchor,
+  onPick,
+  onClose,
+}: {
+  anchor: { x: number; y: number };
+  onPick: (emoji: string) => void;
+  onClose: () => void;
+}) {
+  const isMobile = useMediaQuery("(max-width: 767px)");
+
+  // Desktop only: Escape closes. The drawer handles its own dismissal, and a
+  // popover deliberately doesn't lock scrolling behind it.
+  useEffect(() => {
+    if (isMobile) return;
+    const onKey = (e: KeyboardEvent) => e.key === "Escape" && onClose();
+    document.addEventListener("keydown", onKey);
+    return () => document.removeEventListener("keydown", onKey);
+  }, [isMobile, onClose]);
+
+  const grid = (
+    <div className="space-y-4 p-3">
+      {EMOJI_GROUPS.map((group) => (
+        <section key={group.label}>
+          <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-muted-foreground">
+            {group.label}
+          </h3>
+          <div className="grid grid-cols-8 gap-1">
+            {group.emojis.map((emoji) => (
+              <button
+                key={emoji}
+                type="button"
+                onClick={() => {
+                  onClose();
+                  onPick(emoji);
+                }}
+                aria-label={`React ${emoji}`}
+                className="inline-flex size-9 items-center justify-center rounded-md text-lg hover:bg-muted"
+              >
+                {emoji}
+              </button>
+            ))}
+          </div>
+        </section>
+      ))}
+    </div>
+  );
+
+  if (isMobile) {
+    return (
+      <Drawer open onOpenChange={(o) => !o && onClose()}>
+        <DrawerContent className="bg-card">
+          <DrawerHeader className="text-left">
+            <DrawerTitle>Pick a reaction</DrawerTitle>
+            <DrawerDescription>
+              Choose any emoji to react with.
+            </DrawerDescription>
+          </DrawerHeader>
+          <div className="max-h-[45vh] overflow-y-auto overscroll-contain">
+            {grid}
+          </div>
+        </DrawerContent>
+      </Drawer>
+    );
+  }
+
+  if (typeof document === "undefined") return null;
+
+  // Opens upward: the "+" sits in a menu raised over a message, so there is
+  // usually more room above it than below. Flips down only if that would clip.
+  let left = anchor.x - POPOVER_W / 2;
+  if (left + POPOVER_W > window.innerWidth - EDGE_PAD) {
+    left = window.innerWidth - POPOVER_W - EDGE_PAD;
+  }
+  if (left < EDGE_PAD) left = EDGE_PAD;
+
+  // Room above the button, less a small gap and the viewport edge.
+  const roomAbove = anchor.y - 8 - EDGE_PAD;
+  // Open upward when there is any reasonable room, which by the composer
+  // there almost always is.
+  const openUp = roomAbove > 160;
+  // Anchored by whichever edge faces the button, so the panel hugs it
+  // regardless of how tall its contents actually are. Positioning by top
+  // minus a MAX height floats it away whenever the content is shorter.
+  const vertical = openUp
+    ? { bottom: window.innerHeight - anchor.y + 8 }
+    : { top: anchor.y + 8 };
+  // Never taller than the space it has.
+  const maxH = Math.min(
+    POPOVER_H,
+    openUp ? roomAbove : window.innerHeight - anchor.y - 8 - EDGE_PAD,
+  );
+
+  return createPortal(
+    <>
+      {/* Catches the outside click. Transparent — a popover dims nothing. */}
+      <div className="fixed inset-0 z-[60]" onClick={onClose} aria-hidden />
+      <div
+        role="dialog"
+        aria-label="Pick a reaction"
+        style={{ left, ...vertical, width: POPOVER_W, maxHeight: maxH }}
+        className="fixed z-[61] flex flex-col overflow-hidden rounded-xl border border-border bg-card shadow-lg"
+      >
+        <div className="flex-1 overflow-y-auto">{grid}</div>
+      </div>
+    </>,
+    document.body,
+  );
+}
diff --git a/components/chat/shared-post-card.tsx b/components/chat/shared-post-card.tsx
index afe47a99..1503ebc0 100644
--- a/components/chat/shared-post-card.tsx
+++ b/components/chat/shared-post-card.tsx
@@ -19,7 +19,7 @@ export function SharedPostCard({ attachment }: { attachment: Attachment }) {
 
   if (!post || attachment.entity_unavailable) {
     return (
-      <div className="flex items-center gap-2 rounded-lg border border-border bg-muted/30 px-3 py-2.5">
+      <div className="flex w-full items-center gap-2 rounded-lg border border-border bg-muted/30 px-3 py-2.5 sm:max-w-64">
         <ImageOff className="size-4 shrink-0 text-muted-foreground" aria-hidden />
         <span className="text-sm text-muted-foreground">
           This post is no longer available
@@ -31,7 +31,11 @@ export function SharedPostCard({ attachment }: { attachment: Attachment }) {
   return (
     <Link
       href={`/u/${encodeURIComponent(post.author_handle)}/posts#post-${post.id}`}
-      className="block overflow-hidden rounded-lg border border-border bg-card transition-colors hover:bg-muted/40"
+      // Capped on wide screens. The bubble allows 78% of the column, which on
+      // a phone is a sensible ~265px but on desktop is over 500px — and with
+      // a square image that makes a shared post taller than the viewport.
+      // Mobile keeps the bubble's own width; only sm+ needs the ceiling.
+      className="block w-full overflow-hidden rounded-lg border border-border bg-card transition-colors hover:bg-muted/40 sm:max-w-64"
     >
       <span className="flex items-center gap-2 px-3 py-2">
         <UserAvatar
diff --git a/components/chat/sticker-picker.tsx b/components/chat/sticker-picker.tsx
index f8fc66cb..8de203fc 100644
--- a/components/chat/sticker-picker.tsx
+++ b/components/chat/sticker-picker.tsx
@@ -1,28 +1,54 @@
 "use client";
 
 /**
- * The sticker drawer, opened from the composer.
+ * The sticker picker: a popover anchored to the composer's sticker button on
+ * desktop, a bottom drawer on mobile.
+ *
+ * A popover rather than a modal on desktop because picking a sticker is a
+ * quick aside from typing — a modal takes over the screen and hides the
+ * thread you're replying to. On touch, where there is nothing to anchor to
+ * and the keyboard is already occupying the lower half, the drawer is the
+ * right shape.
  *
  * The collection is whatever the server says it is — rewards earned through
  * sādhana plus stickers saved from a chat — so a sticker you were sent
- * appears here the moment you keep it, with no client-side bookkeeping.
+ * appears the moment you keep it, with no client-side bookkeeping.
  *
  * Empty is a real state worth explaining: stickers are earned, so someone
  * with none needs to know how to get one rather than seeing a blank sheet.
  */
 
 import { useEffect, useState } from "react";
+import { createPortal } from "react-dom";
 import Image from "next/image";
-import { ResponsiveDialog } from "@/components/chat/responsive-dialog";
+import { useMediaQuery } from "@/components/selection-toolbar/shared";
+import {
+  Drawer,
+  DrawerContent,
+  DrawerDescription,
+  DrawerHeader,
+  DrawerTitle,
+} from "@/components/ui/drawer";
 import { chat, type Sticker } from "@/lib/chat";
 
+/** Where the popover hangs from — the sticker button's viewport rect. */
+export type StickerAnchor = { x: number; y: number };
+
+const POPOVER_W = 320;
+const POPOVER_H = 300;
+const EDGE_PAD = 8;
+
 export function StickerPicker({
+  anchor,
   onPick,
   onClose,
 }: {
+  /** Ignored on mobile, which uses a drawer. */
+  anchor: StickerAnchor | null;
   onPick: (sticker: Sticker) => void;
   onClose: () => void;
 }) {
+  const isMobile = useMediaQuery("(max-width: 767px)");
   const [stickers, setStickers] = useState<Sticker[] | null>(null);
 
   useEffect(() => {
@@ -40,21 +66,26 @@ export function StickerPicker({
     };
   }, []);
 
-  return (
-    <ResponsiveDialog
-      title="Stickers"
-      description="Earned through sādhana, or saved from a chat."
-      onClose={onClose}
-    >
+  // Desktop only: Escape closes. The drawer handles its own dismissal, and no
+  // scroll lock here — a popover shouldn't freeze the thread behind it.
+  useEffect(() => {
+    if (isMobile) return;
+    const onKey = (e: KeyboardEvent) => e.key === "Escape" && onClose();
+    document.addEventListener("keydown", onKey);
+    return () => document.removeEventListener("keydown", onKey);
+  }, [isMobile, onClose]);
+
+  const grid = (
+    <>
       {stickers === null ? (
         <p className="p-4 text-sm text-muted-foreground">Loading…</p>
       ) : stickers.length === 0 ? (
         <p className="p-4 text-sm text-muted-foreground">
-          No stickers yet. Keep your sādhana streak — a sacred reward arrives
-          every 7 days — or save one someone sends you.
+          No stickers yet. Earn through your sādhana streak, or save one when
+          someone sends you.
         </p>
       ) : (
-        <div className="grid grid-cols-4 gap-2 p-4 sm:grid-cols-5">
+        <div className="grid grid-cols-4 gap-2 p-3 sm:grid-cols-5">
           {stickers.map((s) => (
             <button
               key={s.key}
@@ -78,6 +109,74 @@ export function StickerPicker({
           ))}
         </div>
       )}
-    </ResponsiveDialog>
+    </>
+  );
+
+  if (isMobile) {
+    return (
+      <Drawer open onOpenChange={(o) => !o && onClose()}>
+        <DrawerContent className="bg-card">
+          <DrawerHeader className="text-left">
+            <DrawerTitle>Stickers</DrawerTitle>
+            <DrawerDescription>
+              Earned through sādhana, or saved from a chat.
+            </DrawerDescription>
+          </DrawerHeader>
+          <div className="max-h-[45vh] overflow-y-auto overscroll-contain">
+            {grid}
+          </div>
+        </DrawerContent>
+      </Drawer>
+    );
+  }
+
+  if (typeof document === "undefined" || !anchor) return null;
+
+  // Opens UPWARD by default: the composer sits at the bottom of the viewport,
+  // so there is rarely room below it. Flips down only if the anchor is high
+  // enough that upward would clip.
+  let left = anchor.x - POPOVER_W / 2;
+  if (left + POPOVER_W > window.innerWidth - EDGE_PAD) {
+    left = window.innerWidth - POPOVER_W - EDGE_PAD;
+  }
+  if (left < EDGE_PAD) left = EDGE_PAD;
+
+  // Room above the button, less a small gap and the viewport edge.
+  const roomAbove = anchor.y - 8 - EDGE_PAD;
+  // Open upward when there is any reasonable room, which by the composer
+  // there almost always is.
+  const openUp = roomAbove > 160;
+  // Anchored by whichever edge faces the button, so the panel hugs it
+  // regardless of how tall its contents actually are. Positioning by top
+  // minus a MAX height floats it away whenever the content is shorter.
+  const vertical = openUp
+    ? { bottom: window.innerHeight - anchor.y + 8 }
+    : { top: anchor.y + 8 };
+  // Never taller than the space it has.
+  const maxH = Math.min(
+    POPOVER_H,
+    openUp ? roomAbove : window.innerHeight - anchor.y - 8 - EDGE_PAD,
+  );
+
+  return createPortal(
+    <>
+      {/* Catches the outside click. Transparent — a popover dims nothing. */}
+      <div className="fixed inset-0 z-50" onClick={onClose} aria-hidden />
+      <div
+        role="dialog"
+        aria-label="Stickers"
+        style={{ left, ...vertical, width: POPOVER_W, maxHeight: maxH }}
+        className="fixed z-[51] flex flex-col overflow-hidden rounded-xl border border-border bg-card shadow-lg"
+      >
+        <div className="border-b border-border px-3 py-2">
+          <p className="text-xs font-medium text-foreground">Stickers</p>
+          <p className="text-[11px] text-muted-foreground">
+            Earned through sādhana, or saved from a chat.
+          </p>
+        </div>
+        <div className="flex-1 overflow-y-auto">{grid}</div>
+      </div>
+    </>,
+    document.body,
   );
 }