HTML中的页脚问题

Question

以下是我的页脚部分的HTML代码：

<footer>
    <div class="footer">
    <nav>
    <ul class="nav-list1">
    <li><img src="img/article-logo.png"  alt="img"/></li>
         </ul>
     <ul class="nav-list2">
    <li>ABOUT</li>
    <li>AUTHOURS</li>
    </ul>
    </nav>
     <hr class="hr-style" />
     <section class="footer-column">
     <div class="footer-column1">
      <img src="img/dot-net-ad.jpg" class="footer-image" alt="dot"/> 
                  <p class="footer-title">.NET Training</p>
                  <p class="footer-pgf">If you have a .NET question on a topic that 's not covered by other more specific forums.</p>
                  <a class="footer-link" href="#">ask here. ></a> 

     </div>
     <div class="footer-column2">
           <img src="img/shopify-expert-ad.jpg" class="footer-image" alt="expert"/> 
                  <p class="footer-title">Shopify Expert</p>
            </div>
       </section>
       <hr class="hr-style" />
       <p class="copyright">Copyright &copy; 2013 Dot Net How</p>
    </div>
    </footer>

并且，这是我的页脚样式：

nav {
    text-align : center;
}

.footer {
    background-image : url('../img/footer-bg.jpg');
    bottom : 0;
    height : auto;
}

我的错误是什么，需要使用什么属性？

Answer 1

根据照片高度使用padding-top：

.footer {
    background:url(img/footer-bg.jpg) top center no-repeat;
    padding-top:100px;
}