プルダウンのヘッダーcss

相当苦戦したが。。。

#header {
	position: relative;
	height: 45px;
	margin-bottom: 5px;
	font-size: 14px;
}
#header img {
	vertical-align:top;
}
#header h1 {
	float:left;
	font-size: 20px;
	width: 173px;
	margin-top:10px;
	margin-bottom:0px;
}

#header #helpNav {
	position:absolute;
	top:0;
	right:0;
	margin-right: 15px;
}
#header #helpNav li {
	display: inline;
	margin-left: 10px;
}

#gNav {
	margin-top: 0px;
	float: left;
	width: 100%;
	height:45px;
	background-color: #6a5acd;
}
#gNav li.menu__single {
	position: relative;
	display: inline;
	float: left;
	width: 105px;
	height: 45px;
	line-height: 45px;
	padding-left:15px;
	padding-right:15px;
	background-color:#6a5acd;
}
#gNav li.menu__single a {
	display: block;
	color:#fff;
}
#gNav li.menu__single a:hover {
	display: block;
	color:#999;
}
li.menu__single ul.second_level{
	display:none;
}
li.menu__single:hover ul.second_level{
	position: absolute;
	display: inline;
    top: 45px;
    width: 110px;
    padding-left:10px;
    padding-right:10px;
    background: #6a5acd;
    visibility: visible;
    opacity: 1;
    -webkit-transition: all .2s ease;
    transition: all .2s ease;
}
li.menu__single:hover ul.second_level li{
	display: inline;
	padding-left: 0px;
	font-size:12px;
}

大体やりたいことは実装できた模様♪

さーコンテンツ作っていきますよ！