Bootstrap模板，css背景顏色沒有覆蓋div

Question

我試圖構建我的單頁設計，但每當我嘗試更改div的顏色時，它只會導致一個小框。

HTML：

<div class="sec1 clearfix"> 
    <div class="row"> 
     <h2 class="push_3">About Us</h2> 
     <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p> 
     <p><a class="btn btn-default" href="#" role="button">View details &raquo;</a></p> 
    </div> 
</div> 

CSS：

.sec1 { 
    height: 200px; 
    background-color: red; 
    width: 100%; 
    background-repeat: repeat; 
    display: block; 
} 

所有即時得到http://imgur.com/BADowGl

Answer 1

.sec1 { 
height: 200px; 
background-color: red; 
width: auto; 
background-repeat: repeat; 
position:absolute; 
} 
.sec1 .row{ 
    postion:relative; 
    border:1px solid red; 
    color:green; 
}