html - 调整窗口大小时，div 内的文本向右或向左移动

Question

网页是这样的:http://www.peliculadicto.tk/每次我调整窗口大小时，灰色条内的文本位置:固定在上部，移动到两侧。它永远不会居中。我该如何防止这种情况？

HTML

<div class="headbar">
    <h1 id="logo">
        <a href="url" title="Ver peliculas de terror, de miedo, infantiles">Películas buenas</a>
    </h1>
    <div id="menu">
        <ul>
            <li><a href="url">Inicio</a></li>
            <li><a href="url" class="drop">Peliculas</a></li>   
            <li><a href="url" class="drop">Estrenos</a></li>            
            <li><a href="url">Ranking</a></li><li><a href="url">Proximamente</a></li>
            <li><a href="url">Más vistas</a></li>
        </ul>

        (search) <div id="uwpqsf_idsr"><form id="uwpqsffrom_641" method="get" action="url"><div class="uform_titlesr"></div><input type="hidden" name="unonce" value="4b52cced4e"><input type="hidden" name="uformid" value="641"><input type="hidden" name="s" value="uwpsfsearchtrg"><div class="uwpqsf_classsr"><input id="uwpqsf_id_keysr" type="text" name="skeyword" class="uwpqsftext" placeholder="Busca por título, actor, director, género..." value=""></div></form></div>

    </div>
</div>

CSS

.uwpqsf_classsr { 
    margin-bottom: 1px;
    clear: both;
    position: absolute;
    bottom: 2.5px;
    left: 57px; 
}

.headbar {
    position:fixed;
    top: 0px;
    left: 0px;
    height: 42px;
    width: 100%;
    background-color: #9B9595;
    background-image: -moz-linear-gradient(#B6AAAA,#000000);
    background-image: -webkit-gradient(linear,0% 0,0% 100%,from(#B6AAAA),to(#000000));
    background-image: -webkit-linear-gradient(rgb(177, 185, 185),rgb(73, 68, 73));
    background-image: -o-linear-gradient(#B6AAAA,#000000);
    border-bottom: 1px solid #A29A9A;
    z-index: 3000;
    opacity: 0.65;
}

#menu {
    position: absolute;
    min-width: 700px;
    left: 221px;
}

#menu>ul>li { 
    float:left;
    position:relative;
    height:27px;
    left:370px;
}

Answer 1

这是

#menu {
  left: 221px;
}

就是这样。