css：按钮浮动到顶部。如何水平对齐？

I have the following css :

我有以下css:

img { border-style : none }
a { text-decoration : none } 

#header { width : 100%}
#header #topbar{width:705px;
        padding:3px 10px 0 10px;
        float:left;
        height:30px;
    line-height:22px;
        background-color:#eee;
        max-width:750px;
        -moz-border-radius-bottomleft:3px;
        -moz-border-radius-bottomright:3px;
        -webkit-border-radius-bottom-left:3px;
        -webkit-border-radius-bottom-right:3px;
        }

#header #logo { height : 61px; 
                width : 250px; 
                float : left;                               

    }

/* BUTTONS */

.buttons a, .buttons button{
    display:block;
    float:right;
    margin:0 7px 0 0;
    background-color:#E0EEEE;
    border:1px solid #dedede;
    border-top:1px solid #eee;
    border-left:1px solid #eee;
    font-family:"Lucida Grande", Tahoma, Arial, Verdana, sans-serif;
    font-size:100%;
    line-height:130%;
    text-decoration:none;
    font-weight:bold;
    color:#565656;
    cursor:pointer;
    padding:5px 10px 6px 7px; /* Links */
}
.buttons button{
    width:auto;
    overflow:visible;
    padding:4px 10px 3px 7px; /* IE6 */
}
.buttons button[type]{
    padding:5px 10px 5px 7px; /* Firefox */
    line-height:17px; /* Safari */
}
*:first-child+html button[type]{
    padding:4px 10px 3px 7px; /* IE7 */
}
.buttons button img, .buttons a img{
    margin:0 3px -3px 0 !important;
    padding:0;
    border:none;
    width:16px;
    height:16px;
    }
/* POSITIVE */

button.positive, .buttons a.positive{
    color:#529214;
}
.buttons a.positive:hover, button.positive:hover{
    background-color:#E6EFC2;
    border:1px solid #C6D880;
    color:#529214;
}
.buttons a.positive:active{
    background-color:#529214;
    border:1px solid #529214;
    color:#fff;
}
img {