我如何使按钮居中？

Question

我希望按钮（联系人等）位于导航栏的中间，尝试了很多东西，但它不会成功。 任何帮助都会很难得到！

CSS：

#cssmenu ul,
#cssmenu li,
#cssmenu span,
#cssmenu a {
  margin: 0;
  padding: 0;
  position: relative;
}
#cssmenu {
  height: 49px;
  border-radius: 5px 5px 0 0;
  -moz-border-radius: 5px 5px 0 0;
  -webkit-border-radius: 5px 5px 0 0;
  background: #141414;
  background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAxCAIAAACUDVRzAA3NCSVQICAjb4U/gAAAALElEQVQImWMwMrJi+v//PxMDw3+m//8ZoPR/qBgDEhuXGLoeYswhXg8R5gAAdVpfoJ3dB5oAASUVORK5CYII=) 100% 100%; 
  background: -moz-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #32323a), color-stop(100%, #141414));
  background: -webkit-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -o-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -ms-linear-gradient(top, #32323a 0%, #141414 100%);
  background: linear-gradient(to bottom, #32323a 0%, #141414 100%);
  border-bottom: 2px solid #0fa1e0;
}
#cssmenu:after,
#cssmenu ul:after {
  content: '';
  display: block;
  clear: both;
}
#cssmenu a {
  background: #141414;
  background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAxCAIAAACUDVRzAA3NCSVQICAjb4U/gAAAALElEQVQImWMwMrJi+v//PxMDw3+m//8ZoPR/qBgDEhuXGLoeYswhXg8R5gAAdVpfoJ3dB5oAASUVORK5CYII=) 100% 100%; 
  background: -moz-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #32323a), color-stop(100%, #141414));
  background: -webkit-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -o-linear-gradient(top, #32323a 0%, #141414 100%);
  background: -ms-linear-gradient(top, #32323a 0%, #141414 100%);
  background: linear-gradient(to bottom, #32323a 0%, #141414 100%);
  color: #ff;
  display: inline-block;
  font-family: Helvetica, Arial, Verdana, sans-serif;
  font-size: 12px;
  line-height: 49px;
  padding: 0 20px;
  text-decoration: none;
}
#cssmenu ul {
  list-style: none;
}
#cssmenu > ul {
  float: left;
}
#cssmenu > ul > li {
  float: left;
}
#cssmenu > ul > li:hover:after {
  content: '';
  display: block;
  width: 0;
  height: 0;
  position: absolute;
  left: 50%;
  bottom: 0;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 10px solid #0fa1e0;
  margin-left: -10px;
}
#cssmenu > ul > li:first-child > a {
  border-radius: 5px 0 0 0;
  -moz-border-radius: 5px 0 0 0;
  -webkit-border-radius: 5px 0 0 0;
}
#cssmenu > ul > li:last-child > a {
  border-radius: 0 5px 0 0;
  -moz-border-radius: 0 5px 0 0;
  -webkit-border-radius: 0 5px 0 0;
}
#cssmenu > ul > li.active > a {
  box-shadow: inset 0 0 3px black;
  -moz-box-shadow: inset 0 0 3px black;
  -webkit-box-shadow: inset 0 0 3px black;
  background: #070707;
  background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAxCAIAAACUDVRzAA3NCSVQICAjb4U/gAAAALklEQVQImWNQU9Nh+v//PxMDw3+m//8ZkNj/mRgYIHxy5f//Z0BSi18e2TwS5QG4MGB54HL+mAABJRU5ErkJggg==) 100% 100%; 
  background: -moz-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #26262c), color-stop(100%, #070707));
  background: -webkit-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -o-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -ms-linear-gradient(top, #26262c 0%, #070707 100%);
  background: linear-gradient(to bottom, #26262c 0%, #070707 100%);
}
#cssmenu > ul > li:hover > a {
  background: #070707;
  background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAxCAIAAACUDVRzAA3NCSVQICAjb4U/gAAAALklEQVQImWNQU9Nh+v//PxMDw3+m//8ZkNj/mRgYIHxy5f//Z0BSi18e2TwS5QG4MGB54HL+mAABJRU5ErkJggg==) 100% 100%; 
  background: -moz-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #26262c), color-stop(100%, #070707));
  background: -webkit-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -o-linear-gradient(top, #26262c 0%, #070707 100%);
  background: -ms-linear-gradient(top, #26262c 0%, #070707 100%);
  background: linear-gradient(to bottom, #26262c 0%, #070707 100%);
  box-shadow: inset 0 0 3px black;
  -moz-box-shadow: inset 0 0 3px black;
  -webkit-box-shadow: inset 0 0 3px black;
}
#cssmenu .has-sub {
  z-index: 1;
}
#cssmenu .has-sub:hover > ul {
  display: block;
}
#cssmenu .has-sub ul {
  display: none;
  position: absolute;
  width: 200px;
  top: 100%;
  left: 0;
}
#cssmenu .has-sub ul li {
  *margin-bottom: -1px;
}
#cssmenu .has-sub ul li a {
  background: #0fa1e0;
  border-bottom: 1px dotted #6fc7ec;
  filter: none;
  font-size: 11px;
  display: block;
  line-height: 120%;
  padding: 10px;
}
#cssmenu .has-sub ul li:hover a {
  background: #0c7fb0;
}
#cssmenu .has-sub .has-sub:hover > ul {
  display: block;
}
#cssmenu .has-sub .has-sub ul {
  display: none;
  position: absolute;
  left: 100%;
  top: 0;
}
#cssmenu .has-sub .has-sub ul li a {
  background: #0c7fb0;
  border-bottom: 1px dotted #6db2d0;
}
#cssmenu .has-sub .has-sub ul li a:hover {
  background: #095c80;
}

HTML：

<div id='cssmenu'>
<ul>
   <li class='active'><a href='index.html'><span>About</span></a></li>
   <li><a href='#'><span>Bookings</span></a></li>
   <li><a href='#'><span>Contact</span></a></li>
   <li class='last'><a href='#'><span>Back to the Portal</span></a></li>
</ul>
</div>

Answer 1

根据koala_dev的建议，这里的评论提示变成了答案。 :)

如果您希望将链接置于中心位置，可以使用：

ul {
    text-align:center;
}
li {
    display:inline-block; /* or even just inline */
}

如果您希望在不给出宽度的情况下居中ul，可以使用：

ul {
    display:table;
    margin:auto;
}
li {
   /* use either float or display:inline/inline-block/table-cell/inline-table... any inline-level-box display*/
}