Login screen refreshes, no access

Been using WP for over a year now, but as of last week, once I enter login and password, the login screen will simply clear its contents — no access to the site, just a refreshed login screen. I’ve changed my password via email and in mysql, still no improvement. Have checked wp-login.php and siteurl. This is consistent behavior in Firefox and Safari, across multiple machines.

Any advice is greatly appreciated.