h1{
    text-align: center;
    font-family: "华文彩云";
    font-size: 100px;
    color: blue;
}


body{
  font-family: Arial;
  padding: 10px;
    background-image: url(背景3.gif);
    
background-position: center;
margin: 80px;

}

.card {
  background-color: rgb(255, 255, 255);
    padding: 20px;
    margin-top: 20px;

  }
    /* 创建两列 */
  /* Left column */
  .leftcolumn {   
    float: left;
    width: 75%;
  }
   
  /* 右侧栏 */
  .rightcolumn {
    float: left;
    width: 25%;
  
    padding-left: 20px;
  }
    /* 列后面清除浮动 */
    .row:after {
      content: "";
      display: table;
      clear: both;
    }
      /* 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%;
    }
  }
/* 头顶导航链接*/
.top-bar {
  width: 100%;
  height: 50px;
  margin: 0;
  display: flex;
}
.box-top {
  width: 100%;
  min-width: 1350px;
  background-color: rgba(255,255,255,0.5);
  padding: 20px;
  /*border-bottom-left-radius: 8px;*/
  /*border-bottom-right-radius: 8px;*/
}
.box-top-right{
}

.top-ui {
  width: 100%;
  min-width: 800px;
  height: 50px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.top-ui li{
  width:15%;
  min-width: 50px;
  margin:-5px 50px 0 70px;
  float: left;
  text-align: center;
  display: block;
}
.top-ui a{
  color: black;
  text-decoration: none；
}
.top-ui a:hover{
  color: rgb(217, 94, 94);
}