Horizontal Navigation (Dark Theme)

CSS
html, body {margin:0;padding:0}
body {margin:10px 20px;background-color:#000;color:#fff}
#top nav ul {
  width:940px;
  margin:20px auto 0 auto;
  padding:0;
  height:32px;
  font-family: Arial, Helvetica, sans-serif;
  font-size:0.8em;
  border-bottom:5px solid #9b9b9b;
}
#top nav ul li {
  list-style:none;
  display:block;
  float:left;
  margin:0 5px 0 0;
}
#top nav ul li a {
  color:#fff;
  text-decoration:none;
  padding:5px 30px;
  line-height: 39px;
  font-weight:bold;
  border-radius:5px 5px 0 0;
  background: #313131;
  background: -moz-linear-gradient(top, #313131 0%, #1b1b1b 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#313131), color-stop(100%,#1b1b1b));
  background: -webkit-linear-gradient(top, #313131 0%,#1b1b1b 100%);
  background: -o-linear-gradient(top, #313131 0%,#1b1b1b 100%);
  background: -ms-linear-gradient(top, #313131 0%,#1b1b1b 100%);
  background: linear-gradient(top, #313131 0%,#1b1b1b 100%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#313131', endColorstr='#1b1b1b',GradientType=0 );
  border-top:1px solid #555;
  text-shadow:0 1px 2px #000;
  transition: .1s ease-in-out;
  -webkit-transition: .1s ease-in-out;
  -moz--webkit-transition: .1s ease-in-out;
  -ms-transition-property: .1s ease-in-out;
  position:relative;
  bottom:0px;
}

#top nav ul li a:hover, #top nav ul li a.selected {
  color:#000;
  background: #eeeeee;
  background: -moz-linear-gradient(top, #eeeeee 8%, #9b9b9b 96%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(8%,#eeeeee), color-stop(96%,#9b9b9b));
  background: -webkit-linear-gradient(top, #eeeeee 8%,#9b9b9b 96%);
  background: -o-linear-gradient(top, #eeeeee 8%,#9b9b9b 96%);
  background: -ms-linear-gradient(top, #eeeeee 8%,#9b9b9b 96%);
  background: linear-gradient(top, #eeeeee 8%,#9b9b9b 96%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#eeeeee', endColorstr='#9b9b9b',GradientType=0 );
  border-top:1px solid #fff;
  text-shadow:0 1px 1px #fff;
  position:relative;
}

#top nav ul li a:hover {
  padding: 8px 30px;
  position:relative;
  bottom:3px;
}

.content {
  font-family:Arial, Helvetica, sans-serif;
  line-height:1.5em;
  font-size: 0.8em;
  clear:both;
  width:916px;
  margin:0 auto;
  padding:20px 10px;
  background: #222;
  box-shadow:inset 1px 1px 20px #000;
  border:2px solid #222;
  border-radius: 0 0 10px 10px;
}
.content h2 {font-weight:normal;}
.split {
  box-sizing: border-box;
  -o-box-sizing: border-box;
  -icab-box-sizing: border-box;
  -khtml-box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  width: 447px;
  margin:5px;
  float:left;
  display:block;
  background:#333;
  box-shadow:inset 0 0 20px #000;
  border-radius:10px;
  padding:10px 20px;
  border:1px solid #101010;
}

.section {background:rgba(0,0,0,0.3);}

.button {
  display: inline-block;
  zoom: 1; /* zoom and *display = ie7 hack for display:inline-block */
  *display: inline;
  vertical-align: baseline;
  margin: 0 2px;
  outline: none;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  font: 14px/100% Arial, Helvetica, sans-serif;
  padding: .5em 2em .55em;

  text-shadow: 0 1px 1px rgba(0,0,0,.3);
  -webkit-border-radius: .5em;
  -moz-border-radius: .5em;
  border-radius: .5em;
  -webkit-box-shadow: 0 1px 2px rgba(0,0,0,.2);
  -moz-box-shadow: 0 1px 2px rgba(0,0,0,.2);
  box-shadow: 0 1px 2px rgba(0,0,0,.2);
}
.button:hover {text-decoration:none}
.button:active {position: relative;box-shadow:inset 0 0 5px #000}
.bigrounded {-webkit-border-radius: 2em;-moz-border-radius: 2em;border-radius: 2em}
.medium {font-size: 12px;padding: .4em 1.5em .42em;font-weight:bold}
.small {text-transform:uppercase;font-size: 11px;padding: .2em 1em .275em;font-weight:normal}

.black {
  color: #d7d7d7;
  border: solid 1px #000;
  background: #333;
  background: -webkit-gradient(linear, left top, left bottom, from(#666), to(#000));
  background: -moz-linear-gradient(top,  #666,  #000);
  filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#666666', endColorstr='#000000');
  -webkit-transition: all .2s ease-in;
}
.black:hover {
  background: #000;
  background: -webkit-gradient(linear, left top, left bottom, from(#444), to(#000));
  background: -moz-linear-gradient(top,  #444,  #000);
  filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#444444', endColorstr='#000000');

  -moz-box-shadow:0 0 10px #000;
  -webkit-box-shadow:0 0 10px #000;
  box-shadow:0 0 10px #000;
}
.black:active {
  color: #888;
  background: -webkit-gradient(linear, left top, left bottom, from(#000), to(#444));
  background: -moz-linear-gradient(top,  #000,  #444);
  filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#000000', endColorstr='#666666');
  border:1px solid #000; 

  -moz-box-shadow:inset 0 0 20px #000;
  -webkit-box-shadow:inset 0 0 20px #000;
  box-shadow:inset 0 0 20px #000;
}

/* search form
-------------------------------------- */
.searchform {
  display: inline-block;
  zoom: 1; /* ie7 hack for display:inline-block */
  *display: inline;
  padding: 3px 5px;

  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  border-radius: 10px;

  -webkit-box-shadow: 0 1px 0px rgba(0,0,0,.1);
  -moz-box-shadow: 0 1px 0px rgba(0,0,0,.1);
  box-shadow: 0 1px 0px rgba(0,0,0,.1);

  background: #aaaaaa;
  background: -moz-linear-gradient(top, #aaaaaa 0%, #333333 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#aaaaaa), color-stop(100%,#333333));
  background: -webkit-linear-gradient(top, #aaaaaa 0%,#333333 100%);
  background: -o-linear-gradient(top, #aaaaaa 0%,#333333 100%);
  background: -ms-linear-gradient(top, #aaaaaa 0%,#333333 100%);
  background: linear-gradient(top, #aaaaaa 0%,#333333 100%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#aaaaaa', endColorstr='#333333',GradientType=0 );
}
.searchform input {
  font: normal 12px/100% Arial, Helvetica, sans-serif;
}
.searchform .searchfield {
  background: #fff;
  padding: 6px 6px 6px 8px;
  width: 202px;
  border: solid 1px #333;
  outline: none;

  -webkit-border-radius: 7px;
  -moz-border-radius: 7px;
  border-radius: 7px;

  -moz-box-shadow: inset 0 1px 2px rgba(0,0,0,.2);
  -webkit-box-shadow: inset 0 1px 2px rgba(0,0,0,.2);
  box-shadow: inset 0 1px 2px rgba(0,0,0,.2);
}
.searchform .searchbutton {
  color: #fff;
  border: solid 1px #494949;
  font-size: 11px;
  height: 27px;
  width: 30px;
  text-shadow: 0 1px 1px rgba(0,0,0,.6);

  -webkit-border-radius: 2.5em;
  -moz-border-radius: 2.5em;
  border-radius: 2.5em;

  background: #5b5b5b;
  background: -moz-linear-gradient(top, #5b5b5b 0%, #000000 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#5b5b5b), color-stop(100%,#000000));
  background: -webkit-linear-gradient(top, #5b5b5b 0%,#000000 100%);
  background: -o-linear-gradient(top, #5b5b5b 0%,#000000 100%);
  background: -ms-linear-gradient(top, #5b5b5b 0%,#000000 100%);
  background: linear-gradient(top, #5b5b5b 0%,#000000 100%);
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#5b5b5b', endColorstr='#000000',GradientType=0 );
}

.searchform .searchbutton:hover {
  cursor:pointer;
  border:1px solid #333;
  background:#888;

  -moz-box-shadow:inset 0 0 10px #000;
  -webkit-box-shadow:inset 0 0 10px #000;
  box-shadow:inset 0 0 10px #000;
}

HTML
<div id="top">
    <nav>
        <ul>
            <li><a href="#" class="selected">Home</a></li>
            <li><a href="#">About</a></li>
            <li><a href="#">Contact</a></li>
        </ul>
    </nav>
</div>

<div class="content">
  <div class="split section">
      <h2>Search Bars</h2>
      <form class="searchform">
      <input class="searchfield" type="text" value="Search..." onfocus="if (this.value == 'Search...') {this.value = '';}" onblur="if (this.value == '') {this.value = 'Search...';}" />
      <input class="searchbutton" type="button" value="GO" />
    </form>
  </div>
  <div class="split section">
      <h2>Buttons</h2>
    <a class="button black small" href="#">Small Button</a>
    <a class="button black medium" href="#">Medium Button</a>
    <a class="button black" href="#">Large Button</a>
  </div>
  <br style="clear:both;">
</div>