Parent div not wrapping child div

I want a parent div to be displayed across the entire page. I can do this successfully (see screenshot). When I resize the browser screen, however; my parent div no longer fits across the entire page, which causes its right most child div to be displayed outside of the parent div (see screenshot). Basically, I want my parent div to always wrap its child divs, and to always be displayed across the entire screen.

by dmarquez

HTML

<!DOCTYPE HTML>
	<body>
	    <div id="wrapper">
		<!-- top nav div -->
		    <div id="topnav">
				<a id="logo" class="navlink clearfix">DreamTeam</a>
				<a class="navlink clearfix">Strikers</a>
				<a class="navlink clearfix">Midfielders</a>
				<a class="navlink clearfix">Defenders</a>
				<a id="lastlink" class="navlink clearfix">Goalkeepers</a>
			</div>

			<!-- heading div -->
			<div id="title">
				<h1>Danny's Dream Team</h1>
			</div>

			<!-- starting lineup -->
			<h2> 3-5-2 </h2>
			<div id="field">
			</div>
	    </div>
	</body>

CSS

html, body {
	width: 100%;
	height: 100%;
	margin: 0;
	padding; 0
}
/* ID's */
#title {
	height: 65px;
	width: 99%;
	margin: auto;
}

/* ID FOR PARENT DIV */
#topnav {
	position: relative;
	background-color: #EDEDED;
	height: 70px;
	width: 100%;
	white-space: nowrap;
}

#logo {
	width: 300px;
	font-weight: bold;
	margin-left: 5px;
	font-size: 28px;
	height: auto;
}

#lastlink {
	border: none;
}

/* CLASS FOR CHILD DIVS */
.navlink {
	position: relative;
	font-family: Century Gothic;
	height: auto; 
	font-size: 24px;
	text-align: left;
	line-height: 65px; 
	width: 175px;
	border-right: 1px solid #bdbdbd;
}

.navlink:hover {
	color: #a5a5a5;
	cursor: pointer;
}

/* REGULAR SELECTORS */

h1 {
	text-align: center;
	font-family: Arial Black, sans-serif;
}

a {
	text-decoration: none;
	color: black;
}

a:hover {
	font-size: 20px;
	font-weight: bold;
}

/* CLEARFIX */
/* I USED CLEARFIX SO THAT
TOPNAV WOULD PROPERLY BE DISPLAYED INLINE*/
.clearfix:after {
    content: ".";
    display: block;
    clear: both;
    visibility: hidden;
    line-height: 0;
    height: 0;
}

.clearfix {
    display: inline-block;
}

html[xmlns] .clearfix {
    display: block;
}

* html .clearfix {
    height: 1%;
}