diff --git a/app/javascript/mastodon/features/compose/redesign/header.tsx b/app/javascript/mastodon/features/compose/redesign/header.tsx
index aab54ebd41d..5eb27639973 100644
--- a/app/javascript/mastodon/features/compose/redesign/header.tsx
+++ b/app/javascript/mastodon/features/compose/redesign/header.tsx
@@ -3,7 +3,6 @@ import { useCallback } from 'react';
 import { defineMessages, FormattedMessage, useIntl } from 'react-intl';
 
 import { ArrowsOutSimpleIcon, MinusIcon, XIcon } from '@phosphor-icons/react';
-import { ReadCvLogoIcon } from '@phosphor-icons/react/dist/ssr';
 
 import { IconButton } from '@/mastodon/components/button/redesign';
 import {
@@ -17,8 +16,6 @@ import {
   useAppSelector,
 } from '@/mastodon/store';
 
-import { useBreakpoint } from '../../ui/hooks/useBreakpoint';
-
 import { selectComposeType } from './selectors';
 import classes from './styles.module.scss';
 
@@ -73,27 +70,18 @@ export const ComposeFormHeader: React.FC<{
   noMinimize?: boolean;
 }> = ({ id, noMinimize }) => {
   const intl = useIntl();
+  const dispatch = useAppDispatch();
   const titleMessage = useAppSelector(selectComposeFormTitle);
   const isMinimized = useAppSelector(selectIsMinimized);
 
-  const dispatch = useAppDispatch();
   const onClose = useCallback(() => {
     dispatch(closeComposer());
   }, [dispatch]);
+
   const onMinimize = useCallback(() => {
     dispatch(minimizeComposerToggle());
   }, [dispatch]);
 
-  const isMobile = useBreakpoint('openable');
-
-  if (isMobile && isMinimized && !noMinimize) {
-    return (
-      <IconButton icon={ReadCvLogoIcon} onClick={onMinimize} size='lg'>
-        <FormattedMessage id='compose.expand' defaultMessage='Show composer' />
-      </IconButton>
-    );
-  }
-
   return (
     <header className={classes.header}>
       <h2 id={id}>{intl.formatMessage(titleMessage)}</h2>
diff --git a/app/javascript/mastodon/features/compose/redesign/trigger.module.scss b/app/javascript/mastodon/features/compose/redesign/trigger.module.scss
index 2ed05078571..61045f66ab2 100644
--- a/app/javascript/mastodon/features/compose/redesign/trigger.module.scss
+++ b/app/javascript/mastodon/features/compose/redesign/trigger.module.scss
@@ -1,7 +1,13 @@
 @use '@/styles/mastodon/variables';
 
-.button {
-  &:not(.buttonInline) {
+.buttonWrapper {
+  position: relative;
+
+  @media (prefers-reduced-motion: no-preference) {
+    transition: all 200ms ease-out;
+  }
+
+  &:not(.buttonWrapperInline) {
     position: fixed;
     bottom: var(--space-4);
     right: var(--space-4);
@@ -9,6 +15,12 @@
   }
 }
 
+.buttonWrapperHidden {
+  transform: translateX(calc(100% + var(--space-4)));
+  opacity: 0;
+  transition-timing-function: ease-in;
+}
+
 .composer,
 .composerMinimized {
   position: fixed;
diff --git a/app/javascript/mastodon/features/compose/redesign/trigger.tsx b/app/javascript/mastodon/features/compose/redesign/trigger.tsx
index 4764093a48e..0e99a16b7fc 100644
--- a/app/javascript/mastodon/features/compose/redesign/trigger.tsx
+++ b/app/javascript/mastodon/features/compose/redesign/trigger.tsx
@@ -4,13 +4,16 @@ import { lazy, Suspense, useCallback, useEffect, useState } from 'react';
 import { FormattedMessage } from 'react-intl';
 
 import classNames from 'classnames';
+import { useRouteMatch } from 'react-router';
 
 import {
   ChatCircleDotsIcon,
   NewspaperIcon,
   PenNibIcon,
+  ReadCvLogoIcon,
 } from '@phosphor-icons/react';
 
+import type { IconButtonProps } from '@/mastodon/components/button/redesign';
 import { IconButton } from '@/mastodon/components/button/redesign';
 import {
   Menu,
@@ -20,10 +23,15 @@ import {
 } from '@/mastodon/components/menu';
 import { MenuCard } from '@/mastodon/components/menu/card';
 import { useIdentity } from '@/mastodon/identity_context';
-import { openNewComposer } from '@/mastodon/reducers/slices/composer';
+import {
+  minimizeComposerToggle,
+  openNewComposer,
+} from '@/mastodon/reducers/slices/composer';
 import { useAppDispatch, useAppSelector } from '@/mastodon/store';
 import { isRedesignEnabled } from '@/mastodon/utils/environment';
 
+import { useBreakpoint } from '../../ui/hooks/useBreakpoint';
+
 import { ComposeFormHeader } from './header';
 import classes from './trigger.module.scss';
 
@@ -38,8 +46,13 @@ export const ComposeRedesignButton: React.FC<{
    * Render the button in regular document flow instead of fixed positioning for mobile layout
    */
   inline?: boolean;
-}> = ({ inline }) => {
+}> = ({ inline = false }) => {
   const displayState = useAppSelector((state) => state.composer.displayState);
+  const isMobile = useBreakpoint('openable');
+
+  const hasMobileFloatingActionButton = useHasMobileFloatingActionButton({
+    isMobile,
+  });
 
   // Update viewport based on visual size in order to account for the virtual keyboard.
   const [viewportHeight, setViewportHeight] = useState<null | number>(null);
@@ -69,14 +82,32 @@ export const ComposeRedesignButton: React.FC<{
       [dispatch],
     );
 
+  const toggleMinimize = useCallback(() => {
+    dispatch(minimizeComposerToggle());
+  }, [dispatch]);
+
   const { signedIn } = useIdentity();
 
   if (!isRedesignEnabled() || !signedIn) {
     return null;
   }
 
+  const floatingButtonProps = {
+    inline,
+    hidden: !hasMobileFloatingActionButton,
+  } as const;
+
   if (displayState === 'minimized') {
-    return (
+    return isMobile ? (
+      <FloatingActionButton
+        icon={ReadCvLogoIcon}
+        onClick={toggleMinimize}
+        {...floatingButtonProps}
+        hidden={false} // never hide minimized composer button
+      >
+        <FormattedMessage id='compose.expand' defaultMessage='Show composer' />
+      </FloatingActionButton>
+    ) : (
       <MenuCard className={classes.composerMinimized} elevation={2}>
         <ComposeFormHeader />
       </MenuCard>
@@ -91,21 +122,16 @@ export const ComposeRedesignButton: React.FC<{
     return (
       <Suspense
         fallback={
-          <IconButton
+          <FloatingActionButton
             loading
             icon={PenNibIcon}
-            className={classNames(
-              classes.button,
-              inline && classes.buttonInline,
-            )}
-            variant='solid'
-            size='lg'
+            {...floatingButtonProps}
           >
             <FormattedMessage
               id='compose.new'
               defaultMessage='Write a new post or messsage'
             />
-          </IconButton>
+          </FloatingActionButton>
         }
       >
         <ComposeLazyForm autoFocus className={classes.composer} style={style} />
@@ -116,11 +142,9 @@ export const ComposeRedesignButton: React.FC<{
   return (
     <Menu>
       <MenuTrigger
-        as={IconButton}
+        as={FloatingActionButton}
         icon={PenNibIcon}
-        variant='solid'
-        className={classNames(classes.button, inline && classes.buttonInline)}
-        size='lg'
+        {...floatingButtonProps}
       >
         <FormattedMessage
           id='compose.new'
@@ -148,3 +172,57 @@ export const ComposeRedesignButton: React.FC<{
     </Menu>
   );
 };
+
+const FloatingActionButton: React.FC<
+  {
+    inline: boolean;
+    hidden: boolean;
+  } & IconButtonProps
+> = ({ inline, hidden, ...otherProps }) => {
+  return (
+    // This component uses a wrapper element to prevent its
+    // CSS transitions from messing with the button's own transitions
+    <div
+      className={classNames(
+        classes.buttonWrapper,
+        inline && classes.buttonWrapperInline,
+        hidden && classes.buttonWrapperHidden,
+      )}
+      inert={hidden}
+    >
+      <IconButton variant='solid' size='lg' {...otherProps} />
+    </div>
+  );
+};
+
+function includeMultiColumnPaths(paths: string[]) {
+  return [...paths, ...paths.map((path) => `/deck${path}`)];
+}
+
+const MOBILE_COMPOSE_BUTTON_ALLOW_ROUTES = includeMultiColumnPaths([
+  '/home',
+  '/public',
+  '/lists',
+  '/tags',
+]);
+const MOBILE_COMPOSE_BUTTON_BLOCK_ROUTES = includeMultiColumnPaths([
+  '/lists/new',
+]);
+
+function useHasMobileFloatingActionButton({ isMobile }: { isMobile: boolean }) {
+  const isRouteWithMobileComposeButton = !!useRouteMatch({
+    path: MOBILE_COMPOSE_BUTTON_ALLOW_ROUTES,
+    exact: false,
+  });
+
+  const isRouteWithoutMobileComposeButton = !!useRouteMatch({
+    path: MOBILE_COMPOSE_BUTTON_BLOCK_ROUTES,
+    exact: true,
+  });
+
+  const shouldHideMobileComposeButton =
+    isMobile &&
+    (!isRouteWithMobileComposeButton || isRouteWithoutMobileComposeButton);
+
+  return !shouldHideMobileComposeButton;
+}
diff --git a/app/javascript/mastodon/features/navigation_panel/redesign/mobile_nav.tsx b/app/javascript/mastodon/features/navigation_panel/redesign/mobile_nav.tsx
index 815eeda48a8..f1256e2637c 100644
--- a/app/javascript/mastodon/features/navigation_panel/redesign/mobile_nav.tsx
+++ b/app/javascript/mastodon/features/navigation_panel/redesign/mobile_nav.tsx
@@ -247,6 +247,7 @@ const SlideOutNavigation: React.FC = () => {
       className={classes.slideOutWrapper}
       data-is-open={isOpen}
       ref={overlayRef}
+      inert={!isOpen}
     >
       <animated.div className={classes.slideOut} {...bind()} style={{ x }}>
         <RedesignNavigationPanel mode='slide-out' />