Vertical <ul> drop down from horizontal <ul> - html

Question

I'm trying to create a basic drop-down menu. Whenever I however over "blog", the "wiki" link seems to get dragged into it.
Here's a screenshot to show what I mean:
As you can see, "wiki" is below "march". I want to have "march" drop down from "blog" and keep "wiki" along the green line.
#header {
box-shadow: 0px 0px 5px 2px #000;
border-radius: 15px 15px 15px 15px;
width: 790px;
height: 30px;
line-height: 85%;
background: #002929;
word-spacing: 5px;
}
#header li {
display: inline;
}
#header ul ul {
display: none;
}
#header ul li:hover > ul {
display: block;
}
#header a:hover {
background: #0147FA;
border-radius: 15px 15px 15px 15px;
padding: 2px;
}
#header a {
text-decoration: none;
color: #ffff4c;
}
<div id="header">
<ul>
<li style="font-size:30px"><strong>Home</strong></li>
<li style="font-size:30px"><strong>Blog</strong>
<ul>
<li style="font-size:30px"><strong>March</strong></li>
</ul>
</li>
<li style="font-size:30px"><strong>Wiki</strong></li>
</ul>
</div>
Here's a JSFiddle.

Answer 1

So I cleaned up the css and it seems to work now.
Here is your html below
<div id="header">
<ul>
<li style="font-size:30px"><strong>Home</strong></li>
<li style="font-size:30px"><strong>Blog</strong>
<ul>
<li style="font-size:30px"><strong>March</strong></li>
</ul>
</li>
<li style="font-size:30px"><strong>Wiki</strong></li>
</ul>
</div>
Here is the new css below:
#header {
box-shadow: 0px 0px 5px 2px #000;
border-radius:15px 15px 15px 15px;
width: 790px;
height: 30px;
line-height: 85%;
background: #002929;
word-spacing: 5px;
}
#header li {
display: inline;
}
#header a:hover {
background: #0147FA;
border-radius: 15px 15px 15px 15px;
}
#header a {
text-decoration: none;
color: #ffff4c;
}
#header ul a
{
text-decoration:none;
font-weight:700;
line-height:32px;
padding:0 15px;
}
#header ul li
{
position:relative;
float:left;
margin:0;
padding:0
}
#header ul ul
{
display:none;
position:absolute;
top:100%;
left:0;
padding:0
}
#header ul li:hover > ul
{
display:block
}
Be sure to compare to see the differences between your css and my css. If this is is not what you wanted please get back to me.