Fix emoji picker button scrolling with textarea content in single-column view (#25304)

app/javascript/mastodon/features/compose/components/compose_form.jsx

@@ -280,13 +280,12 @@ class ComposeForm extends ImmutablePureComponent {
             autoFocus={autoFocus}
             lang={this.props.lang}
           >
-            <EmojiPickerDropdown onPickEmoji={this.handleEmojiPick} />
-
             <div className='compose-form__modifiers'>
               <UploadFormContainer />
               <PollFormContainer />
             </div>
           </AutosuggestTextarea>
+          <EmojiPickerDropdown onPickEmoji={this.handleEmojiPick} />
 
           <div className='compose-form__buttons-wrapper'>
             <div className='compose-form__buttons'>

app/javascript/styles/mastodon/components.scss

@@ -2891,6 +2891,7 @@ $ui-header-height: 55px;
   border-radius: 4px;
   transition: box-shadow 300ms linear;
   min-height: 0;
+  position: relative;
 
   &.active {
     transition: none;