hello Oxwall's 
first sorry for my bad English
to day i will show you who to customize 
your join button with CSS + HTML CODE
LIKE THIS ONE demo  http://www.ar-lady.net/

التسجيل في الموقع

easy
1 - go to your website.com > Admin Area > settings > languages
NOW

go to the search form and type (join) press go
2 - you will find (join) in the bottom of the page
delete "join" word and change it with this
css + html code


NOtE : COPY full HTML AND PAST IN THE FORM
<style type="text/css">
.classname {
    -moz-box-shadow:inset 0px 1px 0px 0px #fbafe3;
    -webkit-box-shadow:inset 0px 1px 0px 0px #fbafe3;
    box-shadow:inset 0px 1px 0px 0px #fbafe3;
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #ff5bb0), color-stop(1, #ef027d) );
    background:-moz-linear-gradient( center top, #ff5bb0 5%, #ef027d 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ff5bb0', endColorstr='#ef027d');
    background-color:#ff5bb0;
    -moz-border-radius:6px;
    -webkit-border-radius:6px;
    border-radius:6px;
    border:1px solid #ee1eb5;
    display:inline-block;
    color:#ffffff;
    font-family:arial;
    font-size:15px;
    font-weight:bold;
    padding:6px 24px;
    text-decoration:none;
    text-shadow:1px 1px 0px #c70067;
}.classname:hover {
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #ef027d), color-stop(1, #ff5bb0) );
    background:-moz-linear-gradient( center top, #ef027d 5%, #ff5bb0 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ef027d', endColorstr='#ff5bb0');
    background-color:#ef027d;
}.classname:active {
    position:relative;
    top:1px;
}
</style>
<a href="http://www.ar-lady.net/join" class="classname">التسجيل في الموقع</a>


CHANGE التسجيل في الموقع
WITH ANY WORD YOU LIKE
AND CHANE URL http://www.ar-ldy.net/join
with any link you want