/* 这是引入了一些字体 */
@import url('https://fonts.googleapis.com/css?family=Poppins:300,400,500,600,700,800,900&display=swap'); 

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
  /* 当用户手动导航或者 CSSOM scrolling API 触发滚动操作时 */
  scroll-behavior: smooth; 
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background: linear-gradient(#48a9ea,#edffff); 
}

header {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  padding: 30px 100px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 10000;
}

header .logo {
  color: #fff;
  font-weight: 700;
  text-decoration: none;
  font-size: 2em;
  text-transform: uppercase; /* 大写 */
  letter-spacing: 2px; /* 字符间距 */
}

header ul {
  display: flex;
  justify-content: center;
  align-items: center;
}

header ul li {
  list-style: none;
  margin-left: 20px;
}

header ul li a {
  text-decoration: none;
  padding: 6px 15px;
  color: #fff;
  border-radius: 20px;
}

header ul li a:hover,
header ul li a.active {
  background: #fff;
  color: #55aaff;
}

section {
  position: relative;
  width: 100%;
  height: 100vh;
  padding: 100px;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

section::before {
  content: '';
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 100px;
  background: linear-gradient(to top, #f3f5f8, transparent);
  z-index: 1000;
}

section img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  /* object-fit CSS 属性指定可替换元素（例如：<img> 或 <video>）的内容应该如何适应到其使用高度和宽度确定的框。 */
  object-fit: cover;
  pointer-events: none;
}

section img#moon {
  /* mix-blend-mode CSS 属性描述了元素的内容应该与元素的直系父元素的内容和元素的背景如何混合。 */ 
  mix-blend-mode: screen;
}

section img#mountains_front {
  z-index: 10;
}

#text {
  position: absolute;
  text-shadow: 0 0 20px #55aaff;
  color: #fff;
  white-space: nowrap;
  font-size: 5.5vw;
  z-index: 9;
}

#btn {
  text-decoration: none;
  display: inline-block;
  padding: 8px 30px;
  border-radius: 40px;
  background: #fff;
  color: #55aaff;
  font-size: 1.5em;
  z-index: 9;
  transform: translateY(100px);
}

.sec {
  position: relative;
  padding: 100px;
  background: #f3f5f8;
}

.sec h2 {
  font-size: 3.5em;
  margin-bottom: 10px;
  color: #fff;
  text-align:center;
  
}

.sec h3 {
  font-size: 3em;
  margin-bottom: 10px;
  color: #fff;
  text-align:center;
}

.sec p {
  font-size: 2em;
  color: #fff;
  text-align:center;
}

.sec img {
	position: relative;
}

.waikuang {
	display: flex;
	width: 100%;
	height: 300px;
	display: -webkit-flex;
	display: flex;
	-webkit-justify-content: center;
	justify-content: center;
}

.kapian {
	background-color: cornflowerblue;
    margin: 10px;
	border-radius: 10px;
	background: #55aaff;
	padding: 10px;
	width: 200px;
	height: 250px;
	opacity:0.9;
	filter:alpha(opacity=90);
	text-align:center;
	 
}

.kapian:hover{
	margin: 10px;
	border-radius: 10px;
	background:#55aaff;
	padding: 10px;
	width: 210px;
	height: 260px;
	opacity:1.0;
	filter:alpha(opacity=100);
	
}

.kapianwenzi {
	font-size: 1.3em;
	text-decoration: none;
	color: #505050;
}

.tu {
	width: 100%;
}

.tu:hover {
	width: 120%;
	
}

.biaoti1 {
	
   width: 240px;
}

.juzhong {
	
	 display: -webkit-flex;
	    display: flex;
	    -webkit-justify-content: center;
	    justify-content: center;
}
	
.wenhou {
	 color: #fff;
	font-size: 1.2em;

}

.ziti1{
	font-family: Arial, Helvetica, sans-serif;
}

.kapian2{
	margin: 10px;
	border: 1px solid #fff;
	border-radius: 10px;
	padding: 10px; 
    background-color: #eaeff6;
	width: 200px; 
	height: 290px;
	
	transition: 0.3s;
	-webkit-transition: 0.3s; /* Safari */
}
.kapian2:hover{
	border: 1px solid #eaeff6;
	border-radius: 10px;
	padding: 10px; 
    background-color: #f2f7fd;
	width: 220px; 
	height: 319px;
}


.kapian2 img{
	width: 100%; 
	height: 63%;
}



.duanluo1{
	text-align: center; 
	font-size: 14px; 
	margin-top: 5px;
}

.biaoti2{
	text-align: center; 
	font-size: 20px;
	font-family: Arial, Helvetica, sans-serif;
	 margin-top: 10px;
}

.duanluo2{
	text-align: center; 
	font-size: 14px; 
	
	
}
  .sticky-popup {
      position: fixed;
      bottom: 20px;
      right: 20px;
      background-color: #ffffff;
      border: 1px solid #0055ff;
      padding: 10px;
      box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
	  border-radius: 6px 20px 3px;
      z-index: 9999;
	  opacity: 0.5;
    }
	
	  .back-to-top {
	      position: fixed;
	      bottom: 80px;
	      right: 20px;
	      width: 40px;
	      height: 40px;
	      background-color: #adadad;
	      color: #fff;
	      border: none;
	      border-radius: 25%;
	      font-size: 18px;
	      cursor: pointer;
	      display: none;
	      justify-content: center;
	      align-items: center;
		  z-index: 1001;
		  opacity: 0.5;
	    }