diff --git a/frontend/public/icon-maskable-192.png b/frontend/public/icon-maskable-192.png
index 395f73c..32e778b 100644
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diff --git a/frontend/public/icon-maskable-512.png b/frontend/public/icon-maskable-512.png
index 43336b8..f224a78 100644
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diff --git a/frontend/src/components/thread/ThreadView.tsx b/frontend/src/components/thread/ThreadView.tsx
index 6ef64a7..15caa4e 100644
--- a/frontend/src/components/thread/ThreadView.tsx
+++ b/frontend/src/components/thread/ThreadView.tsx
@@ -464,6 +464,8 @@ function MessageItem({
   const t = useT();
   const { locale } = useLocale();
   const [showDetails, setShowDetails] = useState(false);
+  // On a phone the reply / translate / actions buttons get a row of their own.
+  const mobile = useIsMobile();
   // Translation (app/translation.py): the message's languages, as the server
   // found them ("zh-Hans,pl,en"), and the language it is shown in (null: as sent).
   const [language, setLanguage] = useState(message.content_language ?? "");
@@ -511,6 +513,73 @@ function MessageItem({
   const allTargets = replyTargets(message, ownAddresses, "reply_all");
   const multiRecipient = allTargets.to.length + allTargets.cc.length > 1;
 
+  // The full header (From, To, Cc, Subject, Date, Size), opened with ▼.
+  const details = (
+    <dl className="mt-2 grid grid-cols-[auto_1fr] gap-x-3 gap-y-0.5 border-t border-app-border pt-2 text-xs text-app-muted">
+      <dt className="text-app-faint">{t("mail.from")}</dt>
+      <dd className="truncate">{formatList(message.from_addr)}</dd>
+      <dt className="text-app-faint">{t("mail.to")}</dt>
+      <dd className="truncate">{formatList(message.to_addr)}</dd>
+      {message.cc_addr.length > 0 && (
+        <>
+          <dt className="text-app-faint">Cc</dt>
+          <dd className="truncate">{formatList(message.cc_addr)}</dd>
+        </>
+      )}
+      <dt className="text-app-faint">{t("mail.subjectLabel")}</dt>
+      <dd className="truncate">{message.subject || "(no subject)"}</dd>
+      <dt className="text-app-faint">{t("mail.dateLabel")}</dt>
+      <dd>{fmtFull(message.date)}</dd>
+      <dt className="text-app-faint">{t("mail.sizeLabel")}</dt>
+      <dd>{fmtSize(message.size_bytes)}</dd>
+    </dl>
+  );
+
+  // Reply, Translate, Actions and plugin verbs: beside the recipients, or on
+  // a phone on a row below them.
+  const actions = (
+    <>
+      {canReply && (
+        <button
+          className="flex items-center gap-1 text-app-muted hover:text-app-fg"
+          onClick={() => onReply(multiRecipient ? "reply_all" : "reply")}
+        >
+          <Icon name={multiRecipient ? "reply-all" : "reply"} size={14} />
+          {multiRecipient ? t("mail.replyAll") : t("mail.reply")}
+        </button>
+      )}
+      {offerTranslate && (target || translateTo) && (
+        <button
+          className="wm-online-only flex items-center gap-1 text-app-muted hover:text-app-fg"
+          onClick={() => setTranslateTo(translateTo ? null : target)}
+        >
+          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden>
+            <path d="M4 5h9M8.5 3v2M6 5c.6 3.4 2.6 6 6 7.5M11 5c-.6 3.4-2.8 6.3-7 8" />
+            <path d="M13 21l4-10 4 10M14.5 17.5h5" />
+          </svg>
+          {translateTo ? t("mail.showOriginal") : t("mail.translate")}
+        </button>
+      )}
+      <ActionsMenu
+        messageId={message.id}
+        mailboxId={message.mailbox_id}
+        translateLanguages={translateCodes}
+        translateTo={translateTo}
+        onTranslateTo={setTranslateTo}
+        onReply={onReply}
+        onPrint={onPrint}
+        onDelete={onDelete}
+        replyDisabled={!canReply}
+        allLabels={allLabels}
+        messageLabels={messageLabels}
+        onToggleLabel={onToggleLabel}
+        onCreateLabel={onCreateLabel}
+      />
+      {/* Plugin-contributed per-message actions (SPEC §11.3 message.actions). */}
+      <PluginSlot name="message.actions" props={{ messageId: message.id }} />
+    </>
+  );
+
   return (
     <div
       data-testid="message"
@@ -574,7 +643,7 @@ function MessageItem({
                   <span className="truncate">
                     {t("mail.to")} {recipientSummary(message.to_addr)}
                   </span>
-                  <span className="text-[11px] text-app-faint">{showDetails ? "▲" : "▼"}</span>
+                  <span className="shrink-0 text-[11px] text-app-faint">{showDetails ? "▲" : "▼"}</span>
                 </button>
                 <div className="flex shrink-0 items-center gap-3 text-xs">
                   {location && <span className="font-semibold text-app-fg">{location}</span>}
@@ -592,73 +661,22 @@ function MessageItem({
                       }`}
                     />
                   </button>
-                  {canReply && (
-                    <button
-                      className="flex items-center gap-1 text-app-muted hover:text-app-fg"
-                      onClick={() => onReply(multiRecipient ? "reply_all" : "reply")}
-                    >
-                      <Icon name={multiRecipient ? "reply-all" : "reply"} size={14} />
-                      {multiRecipient ? t("mail.replyAll") : t("mail.reply")}
-                    </button>
-                  )}
-                  {offerTranslate && (target || translateTo) && (
-                    <button
-                      className="wm-online-only flex items-center gap-1 text-app-muted hover:text-app-fg"
-                      onClick={() => setTranslateTo(translateTo ? null : target)}
-                    >
-                      <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden>
-                        <path d="M4 5h9M8.5 3v2M6 5c.6 3.4 2.6 6 6 7.5M11 5c-.6 3.4-2.8 6.3-7 8" />
-                        <path d="M13 21l4-10 4 10M14.5 17.5h5" />
-                      </svg>
-                      {translateTo ? t("mail.showOriginal") : t("mail.translate")}
-                    </button>
-                  )}
-                  <ActionsMenu
-                    messageId={message.id}
-                    mailboxId={message.mailbox_id}
-                    translateLanguages={translateCodes}
-                    translateTo={translateTo}
-                    onTranslateTo={setTranslateTo}
-                    onReply={onReply}
-                    onPrint={onPrint}
-                    onDelete={onDelete}
-                    replyDisabled={!canReply}
-                    allLabels={allLabels}
-                    messageLabels={messageLabels}
-                    onToggleLabel={onToggleLabel}
-                    onCreateLabel={onCreateLabel}
-                  />
-                  {/* Plugin-contributed per-message actions (SPEC §11.3 message.actions). */}
-                  <PluginSlot name="message.actions" props={{ messageId: message.id }} />
+                  {!mobile && actions}
                 </div>
               </div>
+              {mobile && (
+                <div className="mb-2 mt-3 flex items-center justify-end gap-4 text-xs">{actions}</div>
+              )}
               {alsoIn.length > 0 && (
                 <div className="mt-0.5 truncate text-xs text-app-faint">
                   {t("mail.alsoIn")} {alsoIn.join(", ")}
                 </div>
               )}
-              {showDetails && (
-                <dl className="mt-2 grid grid-cols-[auto_1fr] gap-x-3 gap-y-0.5 border-t border-app-border pt-2 text-xs text-app-muted">
-                  <dt className="text-app-faint">{t("mail.from")}</dt>
-                  <dd className="truncate">{formatList(message.from_addr)}</dd>
-                  <dt className="text-app-faint">{t("mail.to")}</dt>
-                  <dd className="truncate">{formatList(message.to_addr)}</dd>
-                  {message.cc_addr.length > 0 && (
-                    <>
-                      <dt className="text-app-faint">Cc</dt>
-                      <dd className="truncate">{formatList(message.cc_addr)}</dd>
-                    </>
-                  )}
-                  <dt className="text-app-faint">{t("mail.subjectLabel")}</dt>
-                  <dd className="truncate">{message.subject || "(no subject)"}</dd>
-                  <dt className="text-app-faint">{t("mail.dateLabel")}</dt>
-                  <dd>{fmtFull(message.date)}</dd>
-                  <dt className="text-app-faint">{t("mail.sizeLabel")}</dt>
-                  <dd>{fmtSize(message.size_bytes)}</dd>
-                </dl>
-              )}
+              {showDetails && !mobile && details}
             </div>
           </div>
+          {/* On a phone the full header takes the card's width, not the column beside the avatar. */}
+          {showDetails && mobile && <div className="px-4 pb-2">{details}</div>}
           {/* Plugin-contributed per-message banner (SPEC §11.3 message.banner). */}
           <PluginSlot
             name="message.banner"
@@ -891,12 +909,23 @@ export function ThreadView({
 
   return (
     <div data-testid="thread-view" className="flex h-full flex-col overflow-y-auto bg-app-bg">
-      <div className="sticky top-0 z-10 flex h-[52px] shrink-0 items-center justify-between gap-2 border-b border-app-border bg-app-surface px-4">
+      <div
+        className={`sticky top-0 z-10 flex shrink-0 items-center justify-between gap-2 border-b border-app-border bg-app-surface px-4 ${
+          mobile ? "min-h-[52px] py-2" : "h-[52px]" // on a phone the subject may take two lines
+        }`}
+      >
         <div className="flex min-w-0 items-center gap-2">
-          <h2 className="truncate text-[17px] font-semibold text-app-fg">{subject || "(no subject)"}</h2>
+          <h2
+            className={`text-[17px] font-semibold text-app-fg ${
+              mobile ? "line-clamp-2 break-words leading-snug" : "truncate"
+            }`}
+          >
+            {subject || "(no subject)"}
+          </h2>
           <LabelChips labels={threadLabels} onRemove={(l) => removeThreadLabel.mutate(l)} />
         </div>
-        <div className="flex shrink-0 items-center gap-1">
+        {/* On a phone the icons get twice the room between them. */}
+        <div className={`flex shrink-0 items-center ${mobile ? "gap-5" : "gap-1"}`}>
           {/* Dark message mode (lib/darkMessage.ts) — only the dark theme has it. */}
           {resolvedTheme === "dark" && (
             <button
diff --git a/frontend/src/routes/MailLayout.tsx b/frontend/src/routes/MailLayout.tsx
index 804bf31..51d6059 100644
--- a/frontend/src/routes/MailLayout.tsx
+++ b/frontend/src/routes/MailLayout.tsx
@@ -128,6 +128,8 @@ export function MailLayout() {
   // Smartphone layout: one column at a time — the list, or the reading pane full
   // screen — with the sidebar as a slide-in drawer. Desktop is untouched by it.
   const mobile = useIsMobile();
+  // The reading pane's top bar: icons only on a phone, 20% larger.
+  const paneIcon = mobile ? 19 : 16;
   // Desktop arrangement of list and reading pane (Settings → Appearance, or the
   // list's ⋯ menu → Mailbox display). A phone always uses its own single panel.
   const readingPane = useReadingPane();
@@ -1923,55 +1925,78 @@ export function MailLayout() {
               )}
               {currentFolder === "archive" ? (
                 <>
-                  <ToolbarButton onClick={restore}>
-                    <Icon name="inbox" size={16} />
-                    {t("mail.restore")}
-                  </ToolbarButton>
-                  <ToolbarButton onClick={trash}>
-                    <Icon name="trash" size={16} />
-                    {t("mail.delete")}
-                  </ToolbarButton>
+                  <ToolbarButton
+                    onClick={restore}
+                    iconOnly={mobile}
+                    icon={<Icon name="inbox" size={paneIcon} />}
+                    label={t("mail.restore")}
+                  />
+                  <ToolbarButton
+                    onClick={trash}
+                    iconOnly={mobile}
+                    icon={<Icon name="trash" size={paneIcon} />}
+                    label={t("mail.delete")}
+                  />
                 </>
               ) : currentFolder === "trash" ? (
                 <>
-                  <ToolbarButton onClick={restore}>
-                    <Icon name="inbox" size={16} />
-                    {t("mail.restore")}
-                  </ToolbarButton>
-                  <ToolbarButton onClick={deletePermanent}>
-                    <Icon name="trash" size={16} />
-                    {t("mail.delete")}
-                  </ToolbarButton>
+                  <ToolbarButton
+                    onClick={restore}
+                    iconOnly={mobile}
+                    icon={<Icon name="inbox" size={paneIcon} />}
+                    label={t("mail.restore")}
+                  />
+                  <ToolbarButton
+                    onClick={deletePermanent}
+                    iconOnly={mobile}
+                    icon={<Icon name="trash" size={paneIcon} />}
+                    label={t("mail.delete")}
+                  />
                 </>
               ) : (
                 <>
-                  <ToolbarButton onClick={archive}>
-                    <Icon name="archive" size={16} />
-                    {t("mail.archive")}
-                  </ToolbarButton>
-                  <ToolbarButton onClick={togglePin} active={detailQuery.data.pinned}>
-                    <Icon
-                      name="pin"
-                      size={16}
-                      className={detailQuery.data.pinned ? "text-[rgb(220_129_143)]" : ""}
-                    />
-                    {detailQuery.data.pinned ? t("mail.unpin") : t("mail.pin")}
-                  </ToolbarButton>
-                  <ToolbarButton onClick={trash}>
-                    <Icon name="trash" size={16} />
-                    {t("mail.delete")}
-                  </ToolbarButton>
+                  <ToolbarButton
+                    onClick={archive}
+                    iconOnly={mobile}
+                    icon={<Icon name="archive" size={mobile ? paneIcon - 2 : paneIcon} />}
+                    label={t("mail.archive")}
+                  />
+                  <ToolbarButton
+                    onClick={togglePin}
+                    active={detailQuery.data.pinned}
+                    iconOnly={mobile}
+                    icon={
+                      <Icon
+                        name="pin"
+                        size={paneIcon}
+                        className={detailQuery.data.pinned ? "text-[rgb(220_129_143)]" : ""}
+                      />
+                    }
+                    label={detailQuery.data.pinned ? t("mail.unpin") : t("mail.pin")}
+                  />
+                  <ToolbarButton
+                    onClick={trash}
+                    iconOnly={mobile}
+                    icon={<Icon name="trash" size={paneIcon} />}
+                    label={t("mail.delete")}
+                  />
                   {detailQuery.data.snoozed_until ? (
-                    <ToolbarButton onClick={unsnooze} active>
-                      <Clock size={16} />
-                      {t("snooze.unsnooze")}
-                    </ToolbarButton>
+                    <ToolbarButton
+                      onClick={unsnooze}
+                      active
+                      iconOnly={mobile}
+                      icon={<Clock size={paneIcon} />}
+                      label={t("snooze.unsnooze")}
+                    />
                   ) : (
                     <div className="relative">
-                      <ToolbarButton onClick={() => setSnoozeOpen((v) => !v)} active={snoozeOpen}>
-                        <Clock size={16} />
-                        {t("snooze.action")}
-                      </ToolbarButton>
+                      <ToolbarButton
+                        onClick={() => setSnoozeOpen((v) => !v)}
+                        active={snoozeOpen}
+                        iconOnly={mobile}
+                        icon={<Clock size={paneIcon} />}
+                        label={t("snooze.action")}
+                      />
                       {snoozeOpen && <SnoozeMenu onPick={snoozeThread} onClose={closeSnooze} />}
                     </div>
                   )}
@@ -2338,18 +2363,29 @@ function ToolbarButton({
   onClick,
   active = false,
   children,
+  icon,
+  label,
+  iconOnly = false,
 }: {
   onClick: () => void;
   active?: boolean;
-  children: React.ReactNode;
+  children?: React.ReactNode;
+  /** With ``label``: the icon and its name, the name only for screen readers
+   * and as a tooltip when ``iconOnly`` (the phone layout). */
+  icon?: React.ReactNode;
+  label?: string;
+  iconOnly?: boolean;
 }) {
   return (
     <button
-      className={`wm-online-only flex items-center gap-1.5 rounded px-2.5 py-1 hover:bg-app-hover hover:text-app-fg ${
-        active ? "text-app-fg" : "text-app-muted"
-      }`}
+      className={`wm-online-only flex items-center gap-1.5 rounded py-1 hover:bg-app-hover hover:text-app-fg ${
+        iconOnly ? "px-[18px]" : "px-2.5" // icons only (phone): twice the room between them
+      } ${active ? "text-app-fg" : "text-app-muted"}`}
       onClick={onClick}
+      title={iconOnly ? label : undefined}
     >
+      {icon}
+      {label !== undefined && <span className={iconOnly ? "sr-only" : undefined}>{label}</span>}
       {children}
     </button>
   );