* {
    box-sizing: border-box;
  }
   
body{
    font-family: Arial;
    padding: 10px;
    background: #f1f1f1;
    background: url("photos/bg.png")center center;
    background-attachment: scroll;
	background-repeat:repeat;
	background-position:top;
	margin-right:200px;
    background-size: 100%;
    background-attachment:scroll;
}
  /* 头部标题 */
.header {
    background-color: #dddddd50;
    text-align:center;
    padding: 15px;
  }
h1{
    color:rgba(245, 245, 245, 0.87);
}
  /* 导航条 */
  .topnav {
    overflow: hidden;
    background-color: rgba(51, 51, 51, 0.589);
  }
   
  /* 导航条链接 */
  .topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
  }
   
  /* 链接颜色修改 */
  .topnav a:hover {
    background-color: #ddd;
    color: black;
  }
   
  /* 创建两列 */
  /* Left column */
  .leftcolumn {   
    float: left;
    width: 75%;
  }
   
  /* 右侧栏 */
  .rightcolumn {
    float: left;
    width: 25%;
    background-color: #f1f1f1;
    padding-left: 20px;
  }
   
  /* 图像部分 */
  .fakeimg {
    background-image:url("photos/R.jpg");
  	background-repeat:no-repeat;
	  background-position:center;
    width: 100%;
  }
  .Data1 {
    background-image:url("photos/Data1.png");
  	background-repeat:no-repeat;
	  background-position:center;
  }
  .Data2 {
    background-image:url("photos/Data2.png");
  	background-repeat:no-repeat;
	  background-position:center;
    width: 100%;
  }
  .Data3 {
    background-image:url("photos/Data3.png");
  	background-repeat:no-repeat;
	  background-position:center;
    width: 100%;
  }
    .Data3-2  {
      background-image:url("photos/Data3-2.png");
      background-repeat:no-repeat;
      background-position:center;
      width: 100%;
  }
  .Data4 {
    background-image:url("photos/Data4.png");
  	background-repeat:no-repeat;
	  background-position:center;
    width: 100%;
  }
  /* 文章卡片效果 */
  .card {
    background-color: rgba(255, 255, 255, 0.692);
    padding: 20px;
    margin-top: 10px;
  }
   
  /* 列后面清除浮动 */
  .row:after {
    content: "";
    display: table;
    clear: both;
  }
   
  /* 底部 */
  .footer {
    padding: 20px;
    text-align: center;
    background: rgba(0, 0, 0, 0.678);
    margin-top: 20px;
  }
  /* 响应式布局 - 屏幕尺寸小于 800px 时，两列布局改为上下布局 */
  @media screen and (max-width: 800px) {
    .leftcolumn, .rightcolumn {   
      width: 100%;
      padding: 0;
    }
  }
   
  /* 响应式布局 -屏幕尺寸小于 400px 时，导航等布局改为上下布局 */
  @media screen and (max-width: 400px) {
    .topnav a {
      float: none;
      width: 100%;
    }
  }

  .Summary {
    padding: 20px;
    text-align: left;
    background: rgba(0, 0, 0, 0.322);
    margin-top: 20px;
  }