Multiple file updates and bug fixes

【Contents of fixes】
■Fixed a bug in the Twitter cards settings > Twitter account name setting field.
■Fixed a bug where the Twitter cards settings > Twitter account name setting field was not displayed.
■Fixed the character encoding of some files (archive-project.php).
■Fixed the code of the fixed footer bar for smartphones (fixed the bug that an error message appears in debug mode).
■Fixed the contents of the update notification file.

The following are the files that have been modified for this update.
【Corrected files】
admin/theme-options.php
archive-project.php
css/design-plus.css
css/responsive.css
css/style.css
functions.php
functions/head.php
functions/update_notifier.php
languages/ja.mo
languages/ja.po
style.css

For more information, please visit the download site for purchasers of MONOLITH (tcd042).