如何让我的下拉菜单项与导航栏父项相同？

Question

I am trying to make a drop down menu using only CSS, but i'm having a hard time getting the dropdown menu the same size (width and height) as it's parent:

Working fiddle: HERE

The <nav> section from my HTML:

<nav>
    <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Menu With Menus</a>
            <ul>
                <li><a href="#">opt 1</a></li>
                <li><a href="#">opt 2</a></li>
                <li><a href="#">opt 3</a></li>
            </ul>
        </li>
        <li><a href="#">Whatnot</a></li>                
    </ul>
</nav>

The CSS:

nav ul {
    position: relative;
    display: inline-table;
    list-style: none;
}

nav ul li {
    float:left;
    list-style-type: none;
}

nav ul li a {
    background-color: #dae8ec;
    color: rgb(233,78,31);
    display: block; 
    font-weight: bold; 
    margin: 0 auto;         
    padding: 9px 18px 9px; 
    text-decoration: none;
    border: 1px solid black;
    border-radius: 2px; 
}

nav ul ul {
    display: none;
    position: absolute; 
    top: 100%;
}

nav ul li:hover > ul {
    display: block;
}

nav ul ul li {
    float: none;
    position: relative;
}

nav ul ul li a {
    padding: 7px 30px;
    color: rgb(233,78,31);
}

nav ul li a:hover {
    background: rgb(138, 92, 132);
    color:#dae8ec;
}

Any suggestions? Thanks.

Answer 1

Js Fiddle Demo

<nav>
    <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Menu Withs</a>
            <ul>
                <li><a href="#">opt 1</a></li>
                <li><a href="#">opt 2</a></li>
                <li><a href="#">opt 3</a></li>
            </ul>
        </li>
        <li><a href="#">Whatnot</a></li>                
    </ul>
</nav>

Cheers !!