* {
  box-sizing: border-box;
}

body {
font-family: "Georgia";
background-color: #f1f1f1;
color: white;
}
.container {width: 1100px; height: auto; margin: 0 auto 20px auto; padding: 0; background-color: white;}
.overlay {
	top:0:
  bottom: 0; 
  color:white;
  width: 100%;
  transition: .5s ease;
  opacity:1;
  font-size: 20px;
  padding: 20px;
  text-align: right;
  font-family: "Georgia";
}
a:link {color: #004265;}
a:visited {color: #004265;}
a:hover {color: #000080;}
a:active {color: #000080;}
/* 头部标题 */
.header {
  padding: 1px;
  color:white;
  background: black;
  background-image: url('bk.png');
  background-size: 100% 100%;
  background-repeat: no-repeat;
}
 
.header h1 {
  background: rgba(0, 0, 0, 0.4); 
	text-align: center;
	padding: 10px;
  font-size: 38px;
  color:white;
  font-family: "Georgia";
}
 
/* 导航条 */
.topnav {
  overflow: hidden;
   font-family:"Verdana";
  background-color: #004265;
  position: -webkit-sticky;
  position: sticky;
  top: 0;
  padding: 5px;
}
/* 导航条链接 */
.topnav a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
  

}

 
/* 链接颜色修改 */
.topnav a:hover {
  background-color: #ddd;
  color: black;
}
 
 .topnav a.active {
  background-color: #4CAF50;
  color: white;
}

.topnav .icon {
  display: none;
}

/* 创建两列 */
/* Left column */
.leftcolumn {   
  float: left;
  width: 65%;
}
 
/* 右侧栏 */
.rightcolumn {
  float: left;
  width: 35%;
  font-family: "Georgia";
  padding-left: 10px;
  position: -webkit-sticky;
  position: sticky;
  top: 60px;
}
.rightcolumn ul {
  margin-left: 25px;
  padding-left: 0;
}

.rightcolumn li{
	height: 45px;
}
 
/* 图像部分 */
.fakeimg {
  background-color: #aaa;
  width: 100%;
  padding: 20px;
}
 
/* 文章卡片效果 */
.card {
  padding: 20px;
  color: black;
  margin-top: 20px;
  text-align: justify;
  font-family: "Georgia";
  
}

.card h2{
font-size: 18px;
}

/* 列后面清除浮动 */
.row:after {
  content: "";
  display: table;
  clear: both;
}
 
/* 底部 */
.footer {
  padding: 5px;
  text-align: center;
  background: #004265;
  margin-top: 10px;
  left: 0;
  bottom: 0;
  width: 100%;
}
 .footer h2{
 text-align: center;
 color: white;
 font-size: 15px;
 }

/* 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%;
  }
}