I'm using Twitter bootstrap's bootstrap.min.css for styling my phonegap app. But I do not see the desired UI of DOM elements affected by bootstrap. For example, in Base CSS it is shown that btn btn-primary classed button is colored blue and has some gradient on it. Looks nice. But this thing looks so ugly gray colored if I run this on emulator. Why is that so? Isn't bootstrap good for phonegap?
ADDING CODE AND SCREENSHOT
<!DOCTYPE HTML>
<html>
<head>
<title>Call the cab</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="css/bootstrap-responsive.css" rel="stylesheet">
<link rel="stylesheet" href="css/bootstrap.min.css" type="text/css">
<link rel="stylesheet" href="css/custom.css" type="text/css">
<script src="js/bootstrap.min.js" type="text/javascript"></script>
<script type="text/javascript" src="js/heartcode.js"></script>
<script type="text/javascript" charset="utf-8" src="js/cordova-2.0.0.js"></script>
</head>
<body onload="onLoad();initialize()">
<div id="wrapper" class="container row-fluid ">
<div id="headerdiv" class="span12">
<header style="vertical-align:middle;">
<h1>App Name</h1>
</header>
</div><!--End of header-->
<div id="inputs" class="row-fluid">
<form action="file:///android_asset/www/pickup.html" onsubmit="return saveInputs()" class="form-inline form-actions">
<input type="text" id="pickup" onblur="unlockDestiny();codeAddress(this.value)" class="input-block-level"/>
<input type="text" id="destiny" onblur="codeAddress(this.value)" class="input-block-level"/>
<label class="checkbox">
<input type="checkbox" value="">
Remember this
</label>
<button type="submit" class="btn btn-primary">Save changes</button>
</form>
</div><!--End of inputs-->
</div><!--End of wrapper-->
</body>
</html>