Force HTTPS via .htaccess

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [QSA,L]

RewriteCond %{HTTPS} off
RewriteRule ^.*$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]