请老师帮忙看看我的代码。想知道图片和图片之间的空白怎么去除，底部的空白怎么消去。

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title></title>
  <style type="text/css">
    /*此处写代码*/
    *{margin:0;
        padding:0;
     }
     body{height: 2900px;
     }
    .tb{background:black;
        width:100%;
        height:100px;
        position:absolute;
        top: 0; 
        position: fixed;    
          }
    .logo{
        background:url(http://img1.sycdn.imooc.com/climg//58c0d2d900016ce303000100.png);
        width:300px;
        height:100px;
        float:left;
    }
    .dht{
      width:100px;
      height: auto;
      color: white;
      float: right;
      font-size: 20px;
      line-height: 100px;
      margin-left:30px;
      text-align: center; 
      cursor: pointer;         
    }
    .dht:nth-child(4){margin-left: 40px;}
    .wb{
      background-color: black;
      width: 100%;
      height: 100px;
      bottom: 0;
      position: fixed;

      
    }
    .ljqy{float: left;
      margin: 0 10px}
    .ljq{color: white;
      line-height: 100px;
      float: left;
      margin: 0px 50px;
      text-align: center;
     
      width: 100px;

      }
      .tp1{background: url(http://img1.sycdn.imooc.com/climg//58c0eda50001e12416000480.jpg) top center no-repeat;
      width: 100%;  
      height:500px;
      margin-top: 100px;
      

      }
        
      .tp2{background: url(http://img1.sycdn.imooc.com/climg//58c0edb80001c9f216000480.jpg) top center no-repeat;
      width: 100%;height:500px;

      }
       .tp3{background: url(http://img1.sycdn.imooc.com/climg//58c0edc9000100d516000480.jpg) top center no-repeat;
      width: 100%;height:500px;

       
      }

  </style>  
</head>
<body>
  <!-- 此处写代码 -->
  <div class="tb">
      <div class="logo"></div>
      <div class="dht">手记</div>
      <div class="dht">猿问</div>
      <div class="dht">实战</div>
      <div class="dht">职业路径</div>
      <div class="dht">课程</div>
  </div>
  <div class="tp1"></div>
  <div class="tp2"></div>
  <div class="tp3"></div>
  <div class="wb">
      <div class="ljqy">
        <div class="ljq">网站首页</div>
        <div class="ljq">企业合作</div>
        <div class="ljq">人才招聘</div>
        <div class="ljq">联系我们</div>
        <div class="ljq">常见问题</div>
        <div class="ljq">友情链接</div>
      </div>   
  </div>

  
</body>
</html>

AiChiRol 2018-03-05

源自：CSS网页布局基础 2-7 编程练习