BuddyPress.org

I am using the latest WP and Buddypress updates.
When I view my website on a laptop/desktop the community Login and Register buttons work fine. http://www.thedogsclub.com
However if I use a tablet or mobile, the words Login and Register are in the correct place however the clickable link is not, so when you click on Login nothing happens and when you click on Register you get the Login screen.
I was told to add the following code into Appearance>CSS which I did but the problem is still there.
}
body > div.container_24.container > div.grid_24.header > div:nth-child(1) {
max-width: 100%;
}
.header img {
max-width: 100%;
}

I have asked this on WordPress and on my Theme´s forum but no one is offering any help.
Can some kind person out there help.