Fixed a display bug that occurred on iPhone/Adjusted the layout in the administration screen

■【iPhone】Fixed a bug where the Hatena bookmark icon was not displayed on the share button in the fixed footer bar.
■Adjusted the layout in the theme options admin screen.

The following files have been modified for this update.

【Modified files】
admin/css/my_admin.css
css/footer-bar.css
functions/update_notifier.php
functions/widget/google_search.php
languages/ja.mo
Mlanguages/ja.po
style.css
template-parts/footer-bar.php

【Added files】
img/common/hatenabookmark-logomark.svg