feat(mobile): Wave 4 — RegisterPage responsive + TransferIndicator on settings + MessageInput sheets

- RegisterPage: scroll envelope, iOS-zoom-safe inputs, ≥44px tap targets, mobile-friendly invite chip + swatch row
- TransferIndicator: mounted via MobileScreenHeader.rightActions across every settings/instance screen and inline in MobileChatScreen; touch-close listener; viewport-safe panel width
- MessageInput popovers (emoji/GIF/mention) now route through new InputPopover wrapper — desktop popover, mobile bottom-sheet
- EmojiPicker mobile branch: dynamicWidth + scoped CSS (.emoji-picker-wrapper--mobile) so the <em-emoji-picker> custom element fills the sheet; bigger touch targets (perLine 8, button 40, emoji 28); desktop unchanged
- MessageInput trigger row: mobile-first sizing with md: desktop overrides (40×40 buttons + gap on mobile, 34×34 unchanged on desktop)
- Spec updates: docs/systems/auth.md (RegisterPage responsive contract), docs/systems/uploads.md (TransferIndicator mobile surfaces)

docs/systems/auth.md

@@ -563,6 +563,8 @@ Called by `useAuth()` hook when token exists but user object is null:
 
   **Auth-token source of truth.** During the step-2 avatar upload, the JWT lives in `localStorage` only -- `authStore.token` (Zustand) is still null because step 3 hasn't fired. Both the home `api` client (`api/client.ts`) and the home-origin branch of `setTokenForOriginResolver` in `instanceStore.ts` therefore read the home JWT from `localStorage.getItem('backspace_token')`, never from `authStore.token`. This keeps `transferStore.startUpload` (and any other path that resolves a home-origin bearer) authenticated during the registration window. The two stores are written together everywhere else (`initSession`/`logout`), so the divergence only matters between steps 1 and 3 here.
 
+**Responsive contract.** Auth pages render outside `MobileShell` (they are pre-layout). The `RegisterPage` outer wrapper is a self-contained scroll container -- `h-full overflow-y-auto` on the outermost `<div>` because `#root` is `h-full overflow-hidden` (see `globals.css`). An inner `min-h-full flex items-center justify-center` wrapper centers the card vertically when content fits, and falls back to top-aligned scroll when content exceeds the viewport (as on iOS Safari with the keyboard up, where the visible viewport shrinks by ~300 px). Card width is `max-w-[480px]` with `px-4` outer gutters, `p-6 md:p-8` inner padding (smaller on mobile to reclaim 16 px content area at 360 px viewports). All `<input>` elements override the shared `input-standard` class's `text-sm` with `text-base md:text-sm` -- iOS Safari auto-zooms when an input has font-size <16 px. Primary submit buttons use `py-3 md:py-2.5` to satisfy Apple HIG's ≥44 px tap-target rule on mobile. The closed-registration URL-token chip switches from `inline-flex` (desktop pill) to `flex` (mobile full-width banner) so longer error copy ("Invalid invite link -- please request a new one") wraps cleanly inside a 360 px viewport instead of forcing a single-line pill that overflows. The avatar color swatch row uses `gap-2 md:gap-2.5` so the 7 swatches fit within the 360 px content area. **Note:** `LoginPage` does NOT yet apply the same scroll/iOS-zoom/tap-target treatment; this is a known follow-up since LoginPage's shorter form is less likely to clip. Update both together if revisiting.
+
 ---
 
 ## 8. Federation-Aware Identity Utilities

docs/systems/uploads.md

@@ -203,6 +203,18 @@ When a user sets an avatar/banner or a space sets an icon/banner:
 
 The attachment record for profile images is intentionally deleted -- the authoritative reference moves to the `users.avatar`/`users.banner` or `spaces.icon`/`spaces.banner` column.
 
+### Mobile Transfer-Chrome Surfaces
+
+In-flight transfers (chat attachments, profile/banner uploads) are surfaced via the shared `TransferIndicator` component. Mount points:
+
+- **Chat header (desktop):** every `MainContent.tsx` header variant — DM, group DM, space text channel, voice.
+- **Chat header (mobile):** `MobileChatScreen.tsx` mounts `<TransferIndicator />` in its custom header.
+- **Settings/Instance screens (mobile):** mounted via `MobileScreenHeader.tsx`'s `rightActions` slot on every settings screen — `MobileSettingsScreen` (hub + each direct panel), `MobileInstancePanel`, and the six `settings-instance-*` sub-panel wrappers in `MobileShell.tsx`. This guarantees that a profile-picture or banner upload triggered from settings has visible progress chrome and an abort affordance regardless of the user's current screen.
+
+The component is lightweight when idle — the underlying `transferStore` Map subscription is a single `useMemo` over `Array.from(...).filter(t => t.tray)`, and the rendered button is a small icon (no badge) until at least one transfer is active. Safe to mount on every settings screen without performance impact.
+
+The dropdown panel uses `touchstart` + `mousedown` listeners for click-outside dismissal so a single tap on iOS Safari closes the tray. Panel width is `min(300px, calc(100vw - 16px))` to prevent right-edge clipping on narrow viewports while keeping the desktop panel size unchanged.
+
 ---
 
 ## 5. Thumbnail Generation Details

packages/web/src/components/auth/RegisterPage.tsx

@@ -398,9 +398,16 @@ export function RegisterPage() {
     (inviteRequired && !inviteValid);
 
   return (
-    <div className="min-h-full flex items-center justify-center bg-surface-base relative">
-      <div className="absolute inset-0 bg-[radial-gradient(ellipse_at_top,rgba(124,108,246,0.06)_0%,transparent_50%)]" />
-      <div className="w-full max-w-[480px] bg-surface-elevated rounded-md p-8 shadow-elevation-high relative z-10 overflow-hidden">
+    // Outer scroll container — root is `h-full overflow-hidden`, so this page must own
+    // its own scroll. Without it, mobile users with the keyboard up cannot reach the
+    // submit button on Step 2 (avatar + color picker + display name + buttons exceeds
+    // the visible viewport once the iOS keyboard claims ~300 px). `h-full` (rather than
+    // `min-h-full`) makes this element exactly viewport-height; the inner flex wrapper
+    // uses `min-h-full` so short content still centers vertically.
+    <div className="h-full overflow-y-auto bg-surface-base relative">
+      <div className="absolute inset-0 bg-[radial-gradient(ellipse_at_top,rgba(124,108,246,0.06)_0%,transparent_50%)] pointer-events-none" />
+      <div className="min-h-full flex items-center justify-center px-4 py-6 md:py-10 relative z-10">
+        <div className="w-full max-w-[480px] bg-surface-elevated rounded-md p-6 md:p-8 shadow-elevation-high overflow-hidden">
         {/* Progress dots */}
         <div className="flex justify-center gap-2 mb-5">
           <div className={`w-2 h-2 rounded-full transition-colors duration-300 ${step === 1 ? 'bg-accent-primary' : 'bg-txt-tertiary/30'}`} />
@@ -432,7 +439,9 @@ export function RegisterPage() {
                     value={manualInviteToken}
                     onChange={(e) => setManualInviteToken(e.target.value)}
                     placeholder="Invite code or link"
-                    className="input-standard w-full px-3 py-2 text-sm"
+                    // text-base on mobile prevents iOS Safari from auto-zooming
+                    // when the field is focused (any <input> with font-size <16px triggers zoom).
+                    className="input-standard w-full px-3 py-2 text-base md:text-sm"
                     aria-label="Invite code or link"
                     autoComplete="off"
                   />
@@ -458,30 +467,33 @@ export function RegisterPage() {
               )}
 
               {/* URL-token chip — shown only when registration is closed AND a URL token was provided.
-                  Per spec §4.4: open-registration instances silently ignore the ?invite= param. */}
+                  Per spec §4.4: open-registration instances silently ignore the ?invite= param.
+                  Layout: inline pill on desktop, full-width banner on mobile so the longer
+                  error copy ("Invalid invite link — please request a new one") wraps cleanly
+                  inside a 360 px viewport instead of forcing a single-line pill that overflows. */}
               {urlInviteToken && instanceInfo && !instanceInfo.registrationOpen && (
-                <div className="mb-4 inline-flex items-center gap-2 px-3 py-1.5 rounded-full bg-accent-primary/10 text-accent-primary text-xs">
+                <div className="mb-4 flex md:inline-flex items-start md:items-center gap-2 px-3 py-1.5 rounded-md md:rounded-full bg-accent-primary/10 text-accent-primary text-xs">
                   {inviteChecking ? (
                     <>
-                      <svg className="w-3 h-3 animate-spin" viewBox="0 0 24 24" fill="none">
+                      <svg className="w-3 h-3 animate-spin flex-shrink-0 mt-0.5 md:mt-0" viewBox="0 0 24 24" fill="none">
                         <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
                         <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
                       </svg>
-                      Validating invite...
+                      <span>Validating invite...</span>
                     </>
                   ) : inviteCheck?.valid === true ? (
                     <>
-                      <svg className="w-3 h-3" viewBox="0 0 20 20" fill="currentColor">
+                      <svg className="w-3 h-3 flex-shrink-0 mt-0.5 md:mt-0" viewBox="0 0 20 20" fill="currentColor">
                         <path fillRule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clipRule="evenodd" />
                       </svg>
-                      Using invite: {inviteCheck.name}
+                      <span className="break-all">Using invite: {inviteCheck.name}</span>
                     </>
                   ) : inviteCheck?.valid === false ? (
                     <>
-                      <svg className="w-3 h-3" viewBox="0 0 20 20" fill="currentColor">
+                      <svg className="w-3 h-3 flex-shrink-0 mt-0.5 md:mt-0" viewBox="0 0 20 20" fill="currentColor">
                         <path fillRule="evenodd" d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z" clipRule="evenodd" />
                       </svg>
-                      Invalid invite link — please request a new one
+                      <span>Invalid invite link — please request a new one</span>
                     </>
                   ) : (
                     <>Validating invite...</>
@@ -497,7 +509,8 @@ export function RegisterPage() {
                   type="text"
                   value={username}
                   onChange={(e) => setUsername(e.target.value.toLowerCase())}
-                  className="input-standard w-full py-2.5"
+                  // text-base on mobile prevents iOS Safari zoom-on-focus (<16px triggers it).
+                  className="input-standard w-full py-2.5 text-base md:text-sm"
                   autoFocus
                   autoComplete="username"
                 />
@@ -536,7 +549,7 @@ export function RegisterPage() {
                   type="password"
                   value={password}
                   onChange={(e) => setPassword(e.target.value)}
-                  className="input-standard w-full py-2.5"
+                  className="input-standard w-full py-2.5 text-base md:text-sm"
                   autoComplete="new-password"
                 />
               </div>
@@ -549,7 +562,7 @@ export function RegisterPage() {
                   type="password"
                   value={confirmPassword}
                   onChange={(e) => setConfirmPassword(e.target.value)}
-                  className="input-standard w-full py-2.5"
+                  className="input-standard w-full py-2.5 text-base md:text-sm"
                   autoComplete="new-password"
                 />
               </div>
@@ -557,7 +570,9 @@ export function RegisterPage() {
               <button
                 type="submit"
                 disabled={continueDisabled}
-                className="w-full py-2.5 bg-accent-primary hover:bg-accent-primary/80 text-white font-medium rounded transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+                // py-3 on mobile yields ≥44 px tap target (Apple HIG); py-2.5 keeps the
+                // tighter desktop look from before.
+                className="w-full py-3 md:py-2.5 bg-accent-primary hover:bg-accent-primary/80 text-white font-medium rounded transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
               >
                 Continue
               </button>
@@ -643,7 +658,7 @@ export function RegisterPage() {
                 value={displayName}
                 onChange={(e) => setDisplayName(e.target.value)}
                 placeholder={username.trim() || 'Display name'}
-                className="input-standard w-full py-2.5"
+                className="input-standard w-full py-2.5 text-base md:text-sm"
                 autoComplete="name"
               />
             </div>
@@ -653,7 +668,10 @@ export function RegisterPage() {
               <label className="block text-xs font-bold text-txt-secondary uppercase mb-2">
                 Avatar Color
               </label>
-              <div className="flex gap-2.5 justify-center">
+              {/* Color swatch row: gap tightens on narrow viewports so the 7 swatches
+                  fit inside a 360 px viewport (p-6 inner content area is ~280 px;
+                  7×32 + 6×10 = 284 px would overflow with gap-2.5). */}
+              <div className="flex gap-2 md:gap-2.5 justify-center">
                 {AVATAR_COLORS.map((key) => {
                   const entry = AVATAR_GRADIENT_MAP[key];
                   return (
@@ -679,7 +697,7 @@ export function RegisterPage() {
               type="button"
               onClick={() => handleRegister(false)}
               disabled={isDisabled}
-              className="w-full py-2.5 bg-accent-primary hover:bg-accent-primary/80 text-white font-medium rounded transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+              className="w-full py-3 md:py-2.5 bg-accent-primary hover:bg-accent-primary/80 text-white font-medium rounded transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
             >
               {retryAfter > 0
                 ? `Try again in ${retryAfter}s`
@@ -693,7 +711,8 @@ export function RegisterPage() {
                 type="button"
                 onClick={() => { setError(''); setRetryAfter(0); setDirection('back'); setStep(1); }}
                 disabled={isRegistering}
-                className="text-sm text-txt-tertiary hover:text-txt-secondary transition-colors disabled:opacity-50"
+                // py-2 px-1 widens the tap area on mobile while keeping the visual link style.
+                className="text-sm text-txt-tertiary hover:text-txt-secondary transition-colors disabled:opacity-50 py-2 px-1 -mx-1"
               >
                 Back
               </button>
@@ -701,7 +720,7 @@ export function RegisterPage() {
                 type="button"
                 onClick={() => handleRegister(true)}
                 disabled={isDisabled}
-                className="text-sm text-txt-tertiary hover:text-txt-secondary transition-colors disabled:opacity-50"
+                className="text-sm text-txt-tertiary hover:text-txt-secondary transition-colors disabled:opacity-50 py-2 px-1 -mx-1"
               >
                 Skip for now
               </button>
@@ -709,6 +728,7 @@ export function RegisterPage() {
           </div>
         )}
         </div>
+      </div>
 
       {/* Image Crop Modal */}
       {avatarCropSrc && (

packages/web/src/components/chat/EmojiPicker.tsx

@@ -4,9 +4,16 @@ import data from '@emoji-mart/data';
 
 interface EmojiPickerProps {
   onEmojiSelect: (emoji: { native: string }) => void;
+  /**
+   * Mobile rendering: stretch the picker to fill its container width
+   * (the parent bottom-sheet provides the viewport-wide bounds), use
+   * larger touch targets, and let the picker's own scroll area expand
+   * to consume the available height of the sheet.
+   */
+  mobile?: boolean;
 }
 
-export function EmojiPicker({ onEmojiSelect }: EmojiPickerProps) {
+export function EmojiPicker({ onEmojiSelect, mobile = false }: EmojiPickerProps) {
   const containerRef = useRef<HTMLDivElement>(null);
 
   // Prevent keyboard events from bubbling out (e.g. Enter submitting the chat input)
@@ -18,8 +25,24 @@ export function EmojiPicker({ onEmojiSelect }: EmojiPickerProps) {
     return () => el.removeEventListener('keydown', stop);
   }, []);
 
+  // emoji-mart's Picker computes its own internal width from
+  // `perLine * emojiButtonSize` UNLESS `dynamicWidth` is set, in which case
+  // it stretches to its parent's width. On mobile we want full-viewport.
+  // The mobile sheet wraps this picker in `flex-1 min-h-0 flex flex-col`,
+  // so we make the wrapper fill that space and tell the picker to expand.
+  //
+  // The `<em-emoji-picker>` custom element has no intrinsic stretch behavior:
+  // even with `dynamicWidth: true` it ships with `display: flex` but no
+  // `width: 100%`, so it shrinks to its perLine*emojiButtonSize content width
+  // unless we force it to fill. The `emoji-picker-wrapper--mobile` modifier
+  // applies that override (see globals.css) — desktop keeps the legacy
+  // intrinsic-width sizing.
+  const wrapperClass = mobile
+    ? 'emoji-picker-wrapper emoji-picker-wrapper--mobile flex-1 min-h-0 w-full overflow-hidden'
+    : 'emoji-picker-wrapper';
+
   return (
-    <div ref={containerRef} className="emoji-picker-wrapper">
+    <div ref={containerRef} className={wrapperClass}>
       <Picker
         data={data}
         onEmojiSelect={onEmojiSelect}
@@ -28,10 +51,11 @@ export function EmojiPicker({ onEmojiSelect }: EmojiPickerProps) {
         skinTonePosition="search"
         previewPosition="none"
         navPosition="bottom"
-        perLine={10}
+        perLine={mobile ? 8 : 10}
         maxFrequentRows={2}
-        emojiSize={24}
-        emojiButtonSize={32}
+        emojiSize={mobile ? 28 : 24}
+        emojiButtonSize={mobile ? 40 : 32}
+        dynamicWidth={mobile ? true : false}
         categories={['frequent', 'people', 'nature', 'foods', 'activity', 'places', 'objects', 'symbols', 'flags']}
       />
     </div>

packages/web/src/components/chat/GifPicker.tsx

@@ -4,9 +4,14 @@ import type { GifResult } from '@backspace/shared';
 
 interface GifPickerProps {
   onGifSelect: (url: string) => void;
+  /**
+   * Mobile rendering: drop the desktop fixed dimensions and let the picker
+   * fill its parent (a bottom sheet that controls width + max-height).
+   */
+  mobile?: boolean;
 }
 
-export function GifPicker({ onGifSelect }: GifPickerProps) {
+export function GifPicker({ onGifSelect, mobile = false }: GifPickerProps) {
   const [query, setQuery] = useState('');
   const [debouncedQuery, setDebouncedQuery] = useState('');
   const [results, setResults] = useState<GifResult[]>([]);
@@ -78,17 +83,25 @@ export function GifPicker({ onGifSelect }: GifPickerProps) {
     e.stopPropagation();
   };
 
+  // Mobile: fill parent (sheet sets width + max-height). Desktop: fixed dims
+  // matching the legacy popover footprint.
+  const rootClass = mobile
+    ? 'flex flex-col flex-1 min-h-0 w-full'
+    : 'flex flex-col h-[390px] w-[390px]';
+
   return (
-    <div className="flex flex-col h-[390px] w-[390px]" onKeyDown={handleKeyDown}>
+    <div className={rootClass} onKeyDown={handleKeyDown}>
       {/* Search */}
-      <div className="px-3 pt-2 pb-1.5">
+      <div className="px-3 pt-2 pb-1.5 shrink-0">
         <input
           type="text"
           value={query}
           onChange={(e) => setQuery(e.target.value)}
           placeholder="Search GIFs"
           className="input-search w-full"
-          autoFocus
+          // Auto-focus only on desktop. On mobile this would force the OS
+          // keyboard up the moment the sheet opens, hiding most of the grid.
+          autoFocus={!mobile}
         />
       </div>
 
@@ -141,7 +154,7 @@ export function GifPicker({ onGifSelect }: GifPickerProps) {
       </div>
 
       {/* Attribution */}
-      <div className="px-3 py-1 text-[10px] text-txt-tertiary text-right">
+      <div className="px-3 py-1 text-[10px] text-txt-tertiary text-right shrink-0">
         Powered by Klipy
       </div>
     </div>

packages/web/src/components/chat/InputPopover.tsx

@@ -2,6 +2,7 @@ import React, { useRef, useEffect, useCallback } from 'react';
 import { createPortal } from 'react-dom';
 import { EmojiPicker } from './EmojiPicker';
 import { GifPicker } from './GifPicker';
+import { useUIStore } from '../../stores/uiStore';
 
 export type InputPopoverTab = 'emoji' | 'gif';
 
@@ -15,7 +16,38 @@ interface InputPopoverProps {
   onTabChange: (tab: InputPopoverTab) => void;
 }
 
-export function InputPopover({
+interface SharedTabProps {
+  activeTab: InputPopoverTab;
+  availableTabs: { key: InputPopoverTab; label: string }[];
+  onTabChange: (tab: InputPopoverTab) => void;
+}
+
+function TabBar({ activeTab, availableTabs, onTabChange }: SharedTabProps) {
+  if (availableTabs.length <= 1) return null;
+  return (
+    <div className="flex items-center gap-0.5 px-2 pt-2 pb-1">
+      {availableTabs.map((t) => (
+        <button
+          key={t.key}
+          onClick={() => onTabChange(t.key)}
+          className={`px-3 py-1 rounded-md text-[13px] font-medium transition-colors ${
+            activeTab === t.key
+              ? 'bg-interactive-selected text-txt-primary'
+              : 'text-txt-tertiary hover:text-txt-secondary hover:bg-interactive-hover'
+          }`}
+        >
+          {t.label}
+        </button>
+      ))}
+    </div>
+  );
+}
+
+interface DesktopPopoverProps extends InputPopoverProps {
+  availableTabs: { key: InputPopoverTab; label: string }[];
+}
+
+function DesktopPopover({
   activeTab,
   onClose,
   onEmojiSelect,
@@ -23,7 +55,8 @@ export function InputPopover({
   anchorRef,
   gifEnabled,
   onTabChange,
-}: InputPopoverProps) {
+  availableTabs,
+}: DesktopPopoverProps) {
   const floatingRef = useRef<HTMLDivElement>(null);
 
   // Position above the anchor
@@ -93,15 +126,6 @@ export function InputPopover({
     return () => document.removeEventListener('keydown', handler);
   }, [onClose]);
 
-  const availableTabs: { key: InputPopoverTab; label: string }[] = [
-    { key: 'emoji', label: 'Emoji' },
-  ];
-  if (gifEnabled) {
-    availableTabs.splice(0, 0, { key: 'gif', label: 'GIF' });
-  }
-
-  const showTabs = availableTabs.length > 1;
-
   return createPortal(
     <div
       ref={floatingRef}
@@ -109,36 +133,96 @@ export function InputPopover({
       style={{ top: -9999, left: -9999 }}
     >
       <div className="glass rounded-xl overflow-hidden flex flex-col w-fit max-h-[435px]">
-        {/* Tab bar */}
-        {showTabs && (
-          <div className="flex items-center gap-0.5 px-2 pt-2 pb-1">
-            {availableTabs.map((t) => (
-              <button
-                key={t.key}
-                onClick={() => onTabChange(t.key)}
-                className={`px-3 py-1 rounded-md text-[13px] font-medium transition-colors ${
-                  activeTab === t.key
-                    ? 'bg-interactive-selected text-txt-primary'
-                    : 'text-txt-tertiary hover:text-txt-secondary hover:bg-interactive-hover'
-                }`}
-              >
-                {t.label}
-              </button>
-            ))}
-          </div>
-        )}
-
+        <TabBar activeTab={activeTab} availableTabs={availableTabs} onTabChange={onTabChange} />
         {/* Content */}
         <div className="flex-1 min-h-0 overflow-hidden">
-          {activeTab === 'emoji' && (
-            <EmojiPicker onEmojiSelect={onEmojiSelect} />
-          )}
-          {activeTab === 'gif' && gifEnabled && (
-            <GifPicker onGifSelect={onGifSelect} />
-          )}
+          {activeTab === 'emoji' && <EmojiPicker onEmojiSelect={onEmojiSelect} />}
+          {activeTab === 'gif' && gifEnabled && <GifPicker onGifSelect={onGifSelect} />}
         </div>
       </div>
     </div>,
     document.body,
   );
 }
+
+interface MobileSheetProps extends InputPopoverProps {
+  availableTabs: { key: InputPopoverTab; label: string }[];
+}
+
+function MobileSheet({
+  activeTab,
+  onClose,
+  onEmojiSelect,
+  onGifSelect,
+  gifEnabled,
+  onTabChange,
+  availableTabs,
+}: MobileSheetProps) {
+  // Escape to close (parity with desktop)
+  useEffect(() => {
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') {
+        e.stopPropagation();
+        onClose();
+      }
+    };
+    document.addEventListener('keydown', handler);
+    return () => document.removeEventListener('keydown', handler);
+  }, [onClose]);
+
+  return createPortal(
+    <>
+      {/* Backdrop — single tap (mousedown OR touchstart) closes */}
+      <div
+        className="fixed inset-0 z-[300] bg-black/30"
+        onMouseDown={onClose}
+        onTouchStart={onClose}
+      />
+      {/* Sheet */}
+      <div
+        className="fixed left-0 right-0 z-[301] rounded-t-2xl glass-modal animate-slide-up-sheet flex flex-col"
+        style={{
+          // Sit at the bottom of the visible viewport. On iOS 16.4+ the
+          // `keyboard-inset-height` env var lifts us above the soft keyboard;
+          // on older iOS the 100dvh-based MobileShell layout already shrinks
+          // the visual viewport when the keyboard is open, so bottom:0 lands
+          // just above the keyboard naturally.
+          bottom: 'env(keyboard-inset-height, 0px)',
+          paddingBottom: 'env(safe-area-inset-bottom)',
+          maxHeight: 'min(60dvh, 60vh)',
+        }}
+        onMouseDown={(e) => e.stopPropagation()}
+        onTouchStart={(e) => e.stopPropagation()}
+      >
+        {/* Drag handle */}
+        <div className="w-10 h-1 bg-txt-tertiary/30 rounded-full mx-auto mt-2 mb-1 shrink-0" />
+
+        {/* Tab bar (only when multiple tabs available) */}
+        <TabBar activeTab={activeTab} availableTabs={availableTabs} onTabChange={onTabChange} />
+
+        {/* Content */}
+        <div className="flex-1 min-h-0 overflow-hidden flex flex-col">
+          {activeTab === 'emoji' && <EmojiPicker onEmojiSelect={onEmojiSelect} mobile />}
+          {activeTab === 'gif' && gifEnabled && <GifPicker onGifSelect={onGifSelect} mobile />}
+        </div>
+      </div>
+    </>,
+    document.body,
+  );
+}
+
+export function InputPopover(props: InputPopoverProps) {
+  const isMobile = useUIStore((s) => s.isMobile);
+
+  const availableTabs: { key: InputPopoverTab; label: string }[] = [
+    { key: 'emoji', label: 'Emoji' },
+  ];
+  if (props.gifEnabled) {
+    availableTabs.splice(0, 0, { key: 'gif', label: 'GIF' });
+  }
+
+  if (isMobile) {
+    return <MobileSheet {...props} availableTabs={availableTabs} />;
+  }
+  return <DesktopPopover {...props} availableTabs={availableTabs} />;
+}

packages/web/src/components/chat/MentionPopover.tsx

@@ -5,6 +5,7 @@ import { Avatar } from '../ui/Avatar';
 import { useSpaceStore } from '../../stores/spaceStore';
 import { useFloatingPosition } from '../../hooks/useFloatingPosition';
 import { useCanonicalUserView } from '../../utils/userViewLookup';
+import { useUIStore } from '../../stores/uiStore';
 
 const MAX_RESULTS = 8;
 
@@ -14,33 +15,39 @@ function MentionMemberRow({
   selectedRef,
   onSelect,
   roleColor,
+  mobile,
 }: {
   member: MemberWithUser;
   isSelected: boolean;
   selectedRef: React.RefObject<HTMLDivElement>;
   onSelect: (member: MemberWithUser) => void;
   roleColor: string | undefined;
+  mobile: boolean;
 }) {
   const canonical = useCanonicalUserView(member.user);
   const displayName = canonical.displayName ?? canonical.username;
+  // Mobile: ≥44 px tap target per Apple HIG; desktop: compact list.
+  const rowSizing = mobile
+    ? 'gap-3 px-3 py-2.5 min-h-[44px]'
+    : 'gap-2.5 px-2 py-1.5';
   return (
     <div
       ref={isSelected ? selectedRef : undefined}
       onClick={() => onSelect(member)}
-      className={`flex items-center gap-2.5 px-2 py-1.5 mx-1 rounded cursor-pointer transition-colors ${
+      className={`flex items-center mx-1 rounded cursor-pointer transition-colors ${rowSizing} ${
         isSelected ? 'bg-interactive-selected' : 'hover:bg-interactive-hover'
       }`}
     >
       <Avatar
         src={canonical.avatar}
         name={displayName}
-        size={24}
+        size={mobile ? 28 : 24}
         status={canonical.status}
         userId={canonical.homeUserId ?? canonical.id}
         user={canonical}
       />
       <span
-        className="text-[14px] font-medium truncate"
+        className={`${mobile ? 'text-[15px]' : 'text-[14px]'} font-medium truncate`}
         style={roleColor ? { color: roleColor } : undefined}
       >
         {displayName}
@@ -61,12 +68,144 @@ interface MentionPopoverProps {
   anchorRef: React.RefObject<HTMLElement | null>;
 }
 
+interface ResolvedListProps {
+  filtered: MemberWithUser[];
+  selectedIndex: number;
+  selectedRef: React.RefObject<HTMLDivElement>;
+  onSelect: (member: MemberWithUser) => void;
+  getMemberColor: (member: MemberWithUser) => string | undefined;
+  mobile: boolean;
+}
+
+function MemberList({
+  filtered,
+  selectedIndex,
+  selectedRef,
+  onSelect,
+  getMemberColor,
+  mobile,
+}: ResolvedListProps) {
+  return (
+    <>
+      <div className="px-2 py-1.5 text-[11px] font-bold text-txt-tertiary uppercase tracking-wider">
+        Members
+      </div>
+      {filtered.map((member, i) => (
+        <MentionMemberRow
+          key={member.userId}
+          member={member}
+          isSelected={i === selectedIndex}
+          selectedRef={selectedRef}
+          onSelect={onSelect}
+          roleColor={getMemberColor(member)}
+          mobile={mobile}
+        />
+      ))}
+    </>
+  );
+}
+
+interface DesktopMentionProps extends MentionPopoverProps {
+  filtered: MemberWithUser[];
+  getMemberColor: (member: MemberWithUser) => string | undefined;
+}
+
+function DesktopMention({
+  filtered,
+  selectedIndex,
+  onSelect,
+  anchorRef,
+  getMemberColor,
+}: DesktopMentionProps) {
+  const selectedRef = useRef<HTMLDivElement>(null);
+  const floatingRef = useRef<HTMLDivElement>(null);
+
+  const { style } = useFloatingPosition(anchorRef, floatingRef, {
+    placement: 'top',
+    offset: 4,
+    enabled: filtered.length > 0,
+  });
+
+  // Scroll selected item into view
+  useEffect(() => {
+    selectedRef.current?.scrollIntoView({ block: 'nearest' });
+  }, [selectedIndex]);
+
+  return createPortal(
+    <div ref={floatingRef} style={style} className="w-[280px]">
+      <div className="glass rounded-lg overflow-hidden max-h-[320px] overflow-y-auto scrollbar-thin">
+        <MemberList
+          filtered={filtered}
+          selectedIndex={selectedIndex}
+          selectedRef={selectedRef}
+          onSelect={onSelect}
+          getMemberColor={getMemberColor}
+          mobile={false}
+        />
+      </div>
+    </div>,
+    document.body,
+  );
+}
+
+interface MobileMentionProps extends MentionPopoverProps {
+  filtered: MemberWithUser[];
+  getMemberColor: (member: MemberWithUser) => string | undefined;
+}
+
+function MobileMention({
+  filtered,
+  selectedIndex,
+  onSelect,
+  getMemberColor,
+}: MobileMentionProps) {
+  const selectedRef = useRef<HTMLDivElement>(null);
+
+  // Scroll selected item into view as the user types/arrows
+  useEffect(() => {
+    selectedRef.current?.scrollIntoView({ block: 'nearest' });
+  }, [selectedIndex]);
+
+  // Mention is auto-driven by composer text. Tapping the backdrop should NOT
+  // commit a selection; it should simply let the user keep typing. The mention
+  // popover dismisses naturally when the @-token is deleted/closed by composer
+  // logic. We render a transparent backdrop only to visually scrim, and rely
+  // on the composer's own dismissal flow rather than a click-to-close handler.
+  return createPortal(
+    <>
+      <div className="fixed inset-0 z-[300] bg-black/30 pointer-events-none" />
+      <div
+        className="fixed left-0 right-0 z-[301] rounded-t-2xl glass-modal animate-slide-up-sheet flex flex-col"
+        style={{
+          bottom: 'env(keyboard-inset-height, 0px)',
+          paddingBottom: 'env(safe-area-inset-bottom)',
+          maxHeight: 'min(50dvh, 50vh)',
+        }}
+      >
+        {/* Drag handle */}
+        <div className="w-10 h-1 bg-txt-tertiary/30 rounded-full mx-auto mt-2 mb-1 shrink-0" />
+
+        <div className="flex-1 min-h-0 overflow-y-auto scrollbar-thin">
+          <MemberList
+            filtered={filtered}
+            selectedIndex={selectedIndex}
+            selectedRef={selectedRef}
+            onSelect={onSelect}
+            getMemberColor={getMemberColor}
+            mobile={true}
+          />
+        </div>
+      </div>
+    </>,
+    document.body,
+  );
+}
+
 export function MentionPopover({ query, selectedIndex, onSelect, anchorRef }: MentionPopoverProps) {
   const members = useSpaceStore((s) => s.members);
   const spaces = useSpaceStore((s) => s.spaces);
   const currentSpaceId = useSpaceStore((s) => s.currentSpaceId);
-  const selectedRef = useRef<HTMLDivElement>(null);
-  const floatingRef = useRef<HTMLDivElement>(null);
+  const isMobile = useUIStore((s) => s.isMobile);
 
   const ownerId = spaces.find((s) => s.id === currentSpaceId)?.ownerId;
 
@@ -81,17 +220,6 @@ export function MentionPopover({ query, selectedIndex, onSelect, anchorRef }: Me
       .slice(0, MAX_RESULTS);
   }, [members, query]);
 
-  const { style } = useFloatingPosition(anchorRef, floatingRef, {
-    placement: 'top',
-    offset: 4,
-    enabled: filtered.length > 0,
-  });
-
-  // Scroll selected item into view
-  useEffect(() => {
-    selectedRef.current?.scrollIntoView({ block: 'nearest' });
-  }, [selectedIndex]);
-
   if (filtered.length === 0) return null;
 
   const getMemberColor = (member: MemberWithUser): string | undefined => {
@@ -103,24 +231,27 @@ export function MentionPopover({ query, selectedIndex, onSelect, anchorRef }: Me
     return undefined;
   };
 
-  return createPortal(
-    <div ref={floatingRef} style={style} className="w-[280px]">
-      <div className="glass rounded-lg overflow-hidden max-h-[320px] overflow-y-auto scrollbar-thin">
-        <div className="px-2 py-1.5 text-[11px] font-bold text-txt-tertiary uppercase tracking-wider">
-          Members
-        </div>
-        {filtered.map((member, i) => (
-          <MentionMemberRow
-            key={member.userId}
-            member={member}
-            isSelected={i === selectedIndex}
-            selectedRef={selectedRef}
+  if (isMobile) {
+    return (
+      <MobileMention
+        query={query}
+        selectedIndex={selectedIndex}
         onSelect={onSelect}
-            roleColor={getMemberColor(member)}
+        anchorRef={anchorRef}
+        filtered={filtered}
+        getMemberColor={getMemberColor}
+      />
+    );
+  }
+
+  return (
+    <DesktopMention
+      query={query}
+      selectedIndex={selectedIndex}
+      onSelect={onSelect}
+      anchorRef={anchorRef}
+      filtered={filtered}
+      getMemberColor={getMemberColor}
     />
-        ))}
-      </div>
-    </div>,
-    document.body,
   );
 }

packages/web/src/components/chat/MessageInput.tsx

@@ -710,12 +710,12 @@ export function MessageInput({ channelId, channelName }: MessageInputProps) {
           </div>
         )}
 
-        <div className="flex items-center pl-[10px] pr-1">
+        <div className="flex items-center gap-1 md:gap-0 pl-2 md:pl-[10px] pr-2 md:pr-1">
           {/* File attach button */}
           {canAttachFiles && (
             <button
               onClick={() => fileInputRef.current?.click()}
-              className="w-[34px] h-[34px] flex items-center justify-center rounded-[6px] text-txt-tertiary hover:text-txt-secondary transition-colors flex-shrink-0"
+              className="w-10 h-10 md:w-[34px] md:h-[34px] flex items-center justify-center rounded-[6px] text-txt-tertiary hover:text-txt-secondary transition-colors flex-shrink-0"
               title="Attach file"
               aria-label="Attach file"
             >
@@ -783,7 +783,7 @@ export function MessageInput({ channelId, channelName }: MessageInputProps) {
           {gifEnabled && (
             <button
               onClick={() => togglePopover('gif')}
-              className={`w-[34px] h-[34px] flex items-center justify-center rounded-[6px] transition-colors flex-shrink-0 ${
+              className={`w-10 h-10 md:w-[34px] md:h-[34px] flex items-center justify-center rounded-[6px] transition-colors flex-shrink-0 ${
                 activePopover === 'gif' ? 'text-accent-primary' : 'text-txt-tertiary hover:text-txt-secondary'
               }`}
               title="GIF"
@@ -798,7 +798,7 @@ export function MessageInput({ channelId, channelName }: MessageInputProps) {
           {/* Emoji button */}
           <button
             onClick={() => togglePopover('emoji')}
-            className={`w-[34px] h-[34px] flex items-center justify-center rounded-[6px] transition-colors flex-shrink-0 ${
+            className={`w-10 h-10 md:w-[34px] md:h-[34px] flex items-center justify-center rounded-[6px] transition-colors flex-shrink-0 ${
               activePopover === 'emoji' ? 'text-accent-primary' : 'text-txt-tertiary hover:text-txt-secondary'
             }`}
             title="Emoji"
@@ -814,7 +814,7 @@ export function MessageInput({ channelId, channelName }: MessageInputProps) {
             <button
               onClick={() => void handleSubmit()}
               disabled={anyUnshippable}
-              className="w-[34px] h-[34px] flex items-center justify-center rounded-[6px] bg-accent-primary hover:bg-accent-primary-hover text-white transition-all duration-150 flex-shrink-0 disabled:opacity-50"
+              className="w-10 h-10 md:w-[34px] md:h-[34px] flex items-center justify-center rounded-[6px] bg-accent-primary hover:bg-accent-primary-hover text-white transition-all duration-150 flex-shrink-0 disabled:opacity-50"
               aria-label="Send message"
               title="Send"
             >

packages/web/src/components/layout/MobileInstancePanel.tsx

@@ -2,6 +2,7 @@ import React, { useEffect, useState, useCallback } from 'react';
 import { useUIStore } from '../../stores/uiStore';
 import { useSettingsStore } from '../../stores/settingsStore';
 import { MobileScreenHeader } from './MobileScreenHeader';
+import { TransferIndicator } from './TransferIndicator';
 import { api } from '../../api/client';
 import { onFederationPeersChanged } from '../../hooks/useWebSocket';
 
@@ -135,7 +136,7 @@ export function MobileInstancePanel() {
 
   return (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Instance" />
+      <MobileScreenHeader title="Instance" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto">
         {sections.map((section) => {
           const badge = section.id === 'federation' && approvalCount > 0 ? approvalCount : null;

packages/web/src/components/layout/MobileSettingsScreen.tsx

@@ -5,6 +5,8 @@ import { AccountPanel } from '../modals/settingsPanels/AccountPanel';
 import { VoicePanel } from '../modals/settingsPanels/VoicePanel';
 import { ConnectionsPanel } from '../modals/settingsPanels/ConnectionsPanel';
 import { PrivacyPanel } from '../modals/settingsPanels/PrivacyPanel';
+import { MobileScreenHeader } from './MobileScreenHeader';
+import { TransferIndicator } from './TransferIndicator';
 
 interface MobileSettingsScreenProps {
   initialPanel?: string;
@@ -46,7 +48,6 @@ const sectionIcons: Record<string, React.ReactNode> = {
 };
 
 export function MobileSettingsScreen({ initialPanel }: MobileSettingsScreenProps) {
-  const popMobileScreen = useUIStore((s) => s.popMobileScreen);
   const pushMobileScreen = useUIStore((s) => s.pushMobileScreen);
   const isAdmin = useAuthStore((s) => s.user?.isAdmin);
 
@@ -58,14 +59,7 @@ export function MobileSettingsScreen({ initialPanel }: MobileSettingsScreenProps
 
     return (
       <div className="flex flex-col h-full bg-surface-base">
-        <header className="h-12 flex items-center gap-2 px-3 border-b border-border-soft shrink-0">
-          <button onClick={popMobileScreen} className="w-8 h-8 flex items-center justify-center text-txt-secondary hover:text-txt-primary">
-            <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-              <path strokeLinecap="round" strokeLinejoin="round" d="M15.75 19.5L8.25 12l7.5-7.5" />
-            </svg>
-          </button>
-          <h1 className="text-sm font-semibold text-txt-primary">{panel.title}</h1>
-        </header>
+        <MobileScreenHeader title={panel.title} rightActions={<TransferIndicator />} />
         <div className="flex-1 overflow-y-auto p-4">
           {panel.component}
         </div>
@@ -84,14 +78,7 @@ export function MobileSettingsScreen({ initialPanel }: MobileSettingsScreenProps
 
   return (
     <div className="flex flex-col h-full bg-surface-base">
-      <header className="h-12 flex items-center gap-2 px-3 border-b border-border-soft shrink-0">
-        <button onClick={popMobileScreen} className="w-8 h-8 flex items-center justify-center text-txt-secondary hover:text-txt-primary">
-          <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-            <path strokeLinecap="round" strokeLinejoin="round" d="M15.75 19.5L8.25 12l7.5-7.5" />
-          </svg>
-        </button>
-        <h1 className="text-sm font-semibold text-txt-primary">Settings</h1>
-      </header>
+      <MobileScreenHeader title="Settings" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto">
         {sections.map((section) => (
           <button

packages/web/src/components/layout/MobileShell.tsx

@@ -13,6 +13,7 @@ import { MobileChatScreen } from './MobileChatScreen';
 import { MobileSettingsScreen } from './MobileSettingsScreen';
 import { MobileInstancePanel } from './MobileInstancePanel';
 import { MobileScreenHeader } from './MobileScreenHeader';
+import { TransferIndicator } from './TransferIndicator';
 import { MobileVoiceMiniBar } from './MobileVoiceMiniBar';
 import { MobileVoiceFullScreen } from './MobileVoiceFullScreen';
 import { MobileMembersScreen } from './MobileMembersScreen';
@@ -36,7 +37,7 @@ function MobileFederationPanelWrapper() {
   const setApprovalCount = useUIStore((s) => s.setFederationApprovalCount);
   return (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Federation" />
+      <MobileScreenHeader title="Federation" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4">
         <FederationPanel onApprovalCountChange={setApprovalCount} />
       </div>
@@ -55,32 +56,32 @@ const screenMap: Record<string, (params?: Record<string, string>) => React.React
   'settings-instance': () => <MobileInstancePanel />,
   'settings-instance-general': () => (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="General" />
+      <MobileScreenHeader title="General" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4"><GeneralPanel /></div>
     </div>
   ),
   'settings-instance-registration': () => (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Registration" />
+      <MobileScreenHeader title="Registration" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4"><RegistrationPanel /></div>
     </div>
   ),
   'settings-instance-federation': () => <MobileFederationPanelWrapper />,
   'settings-instance-streaming': () => (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Streaming" />
+      <MobileScreenHeader title="Streaming" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4"><StreamingPanel /></div>
     </div>
   ),
   'settings-instance-storage': () => (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Storage" />
+      <MobileScreenHeader title="Storage" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4"><StoragePanel /></div>
     </div>
   ),
   'settings-instance-users': () => (
     <div className="flex flex-col h-full bg-surface-base">
-      <MobileScreenHeader title="Users" />
+      <MobileScreenHeader title="Users" rightActions={<TransferIndicator />} />
       <div className="flex-1 overflow-y-auto p-4"><UsersPanel /></div>
     </div>
   ),

packages/web/src/components/layout/TransferIndicator.tsx

@@ -30,13 +30,21 @@ export function TransferIndicator() {
   const [open, setOpen] = useState(false);
   const ref = useRef<HTMLDivElement>(null);
 
+  // Click-outside-to-close. iOS Safari does not synthesize `mousedown` from
+  // touch reliably, so we listen for `touchstart` alongside `mousedown` so the
+  // panel dismisses on the first tap on touch devices. Mirrors the pattern
+  // used in AudioInputSection.tsx.
   useEffect(() => {
     if (!open) return;
-    const onClick = (e: MouseEvent) => {
+    const onPointerDown = (e: MouseEvent | TouchEvent) => {
       if (!ref.current?.contains(e.target as Node)) setOpen(false);
     };
-    document.addEventListener('mousedown', onClick);
-    return () => document.removeEventListener('mousedown', onClick);
+    document.addEventListener('mousedown', onPointerDown);
+    document.addEventListener('touchstart', onPointerDown, { passive: true });
+    return () => {
+      document.removeEventListener('mousedown', onPointerDown);
+      document.removeEventListener('touchstart', onPointerDown);
+    };
   }, [open]);
 
   const active = visible.filter(
@@ -69,7 +77,15 @@ export function TransferIndicator() {
         )}
       </button>
       {open && (
-        <div className="absolute right-0 top-full mt-2 w-[300px] max-w-[calc(100vw-1rem)] glass z-50 rounded-lg overflow-hidden">
+        // Desktop: anchor below the trigger via `absolute right-0 top-full`.
+        // Mobile (<768px): switch to `fixed` so the panel pins to the viewport
+        // right edge with an 8px margin instead of inheriting the trigger's
+        // x-position. This prevents left-edge clipping on narrow viewports
+        // (e.g. 320px) where the trigger sits well to the left of the
+        // viewport's right edge — `right-0` would otherwise anchor the
+        // panel to the trigger's right and let the 300px panel extend off
+        // the left of the viewport.
+        <div className="fixed right-2 top-14 md:absolute md:right-0 md:top-full md:mt-2 w-[min(300px,calc(100vw-16px))] glass z-50 rounded-lg overflow-hidden">
           <div className="px-3 py-2 border-b border-border-soft text-xs flex justify-between items-center">
             <span className="text-txt-secondary">
               {visible.length} transfer{visible.length === 1 ? '' : 's'}

packages/web/src/styles/globals.css

@@ -320,6 +320,19 @@
   max-height: 400px;
 }
 
+/* Mobile bottom-sheet variant: stretch the custom element to fill the
+   sheet's width (so `dynamicWidth: true` can recompute the grid against
+   the real container). Height is left to emoji-mart's own layout — the
+   picker manages its internal scroll region against its measured height
+   and forcing `height: 100%` here would collapse its category nav off-
+   screen because the custom element doesn't propagate flex sizing into
+   its shadow root. The 400px desktop cap is fine for mobile too; the
+   sheet's `max-height: min(60dvh, 60vh)` gives us ~440-500px to play
+   with on common phone viewports. */
+.emoji-picker-wrapper--mobile em-emoji-picker {
+  width: 100%;
+}
+
 /* Animations */
 @keyframes fadeIn {
   from { opacity: 0; }