* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

@font-face {
  font-family: 'pingfang';
  src: url('../font/苹方字体.TTF') format('truetype');
}

a {
  text-decoration: none;
  color: rgba(255, 255, 255, 0.9);
  font-size: 20px;
}

/* 头部导航 */
.header {
  width: 100%;
  height: 100px;
  background-color: rgba(71, 195, 206, 0.73);
  position: absolute;
  top: 0;
  left: 0;
  z-index: 100;
}

.nav{
    width: 100%;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'pingfang', sans-serif;
}
.nav-logo{
    width: 130px;
    margin: 15px 45px;
}
.nav-list{
    display: flex;
    list-style: none;
    align-items: center;
}
.nav-list li{
    margin: 30px 45px;
}
.nav-list li a {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.9);
    font-size: 20px;
    position: relative; /* 为伪元素提供定位参考 */
    letter-spacing: 3px;
}

.nav-list li a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: -10px; /* 距离文字底部6px */
    transform: translateX(-50%); /* 水平居中 */
    width: 40px;
    height: 3px;
    background-color: #ffffff; /* 白色背景 */
    opacity: 0; /* 初始隐藏 */
    transition: opacity 0.3s ease; /* 过渡效果 */
}

.nav-list li a:hover::after {
    opacity: 1; /* 鼠标悬停时显示 */
}
.nav-login a{
    margin-left: 20px;
}
.nav-list li a.active::after {
    opacity: 1; /* 激活状态下始终显示下划线 */
}
.banner video {
  width: 100%;
  height: 800px;
  object-fit: cover;
  z-index: -1;
}

.section {
  margin-bottom: 60px;
}

.section-title {
  text-align: center;
  font-size: 30px;
  margin-top: 35px;
  font-family: 'pingfang', sans-serif;
  letter-spacing: 2px;
}

.section-title2 {
  text-align: center;
  font-size: 32px;
  margin-top: 10px;
  margin-bottom: 30px;
  color: #929392;
  font-family: 'pingfang', sans-serif;
  letter-spacing: 2.3px;
}

.swiper {
  width: 65%;
  height: 500px;
  background: #000;
  border-radius: 25px;
}

.swiper-slide {
  font-size: 18px;
  color: #fff;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  padding: 40px 60px;
}
.text p{
    text-align: justify;
    font-family: 'pingfang', sans-serif;
    font-size: 16px;
}

.parallax-bg {
  position: absolute;
  left: 0;
  top: 0;
  width: 130%;
  height: 100%;
  -webkit-background-size: cover;
  background-size: cover;
  background-position: center;
}

.swiper-slide .title {
  font-size: 41px;
  font-weight: 300;
  position: relative;
  top: 250px;
}

.swiper-slide .subtitle {
  font-size: 21px;
}

.swiper-slide .text {
  font-size: 14px;
  max-width: 400px;
  line-height: 1.3;
  position: relative;
  top: 250px;
  line-height: 1.5;
}

.Geography {
  position: relative;
  margin: 0 auto;
  width: 65%;
  height: auto; /* 修复：高度设为auto，让内容自然撑开 */
  margin-bottom: 60px; /* 修复：添加底部间距 */
}

.Geography h2,
.Geography h3 {
  display: inline-block;
}

.north h2 {
  font-family: 'pingfang', sans-serif;
  font-weight: bold;
  margin-bottom: 5px;
}

.north h3 {
  margin-left: 10px;
  color: #c7af1b;
  font-family: 'pingfang', sans-serif;
  font-size: 16px;
  font-weight: normal;
}

.north p {
  font-size: 16px;
  font-family: 'pingfang', sans-serif;
  text-align: justify;
  width: 520px;
  line-height: 1.5;
}

.south h2 {
  font-family: 'pingfang', sans-serif;
  font-weight: bold;
  margin-bottom: 5px;
}

.south h3 {
  margin-left: 10px;
  color: #143e1f;
  font-family: 'pingfang', sans-serif;
  font-size: 16px;
  font-weight: normal;
}

.south p {
  font-size: 16px;
  font-family: 'pingfang', sans-serif;
  text-align: justify;
  width: 520px;
  line-height: 1.5;
}

.north h2,
.north .content p {
  margin-left: -100px;
}

.south h2,
.south .content p {
  margin-left: 600px;
}

.north img {
  width: 100%;
  height: auto;
  margin-top: 60px;
}
.position-name img{
  width: 100%;
  height: auto;
}

#icon img {
  width: 10%;
  height: auto;
  margin-right: 10px;
  object-fit: cover;
  position: relative;
  top: -40px;
  margin-left: 800px;
  margin-bottom: 30px;
}

.photo-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  margin: 0 200px; /* 修复：减小边距，避免内容过窄 */
  justify-content: center;
  position: relative; /* 确保定位正确 */
}

.photo-item {
  width: calc(33.33% - 10px);
  margin-bottom: 10px;
}

.photo-item img {
  width: 100%;
  height: auto;
  display: block;
}
#photo1{
    width: 100%;
    height: auto;
    object-fit: cover;
}
/* .north img {
  transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94), 
              box-shadow 0.5s ease;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  max-width: 800px;
  margin: 20px auto;
}

.north img:hover {
  transform: translateY(-5px) scale(1.02);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
} */
.north img{
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
  transition: all 0.6s cubic-bezier(0.23, 1, 0.32, 1);
  position: relative;
  z-index: 1;
  margin: 50px auto;
  max-width: 800px;
}

.north img:hover{
  transform: scale(1.03);
  filter: brightness(1.1) contrast(1.05);
  box-shadow: 0 0 0 8px rgba(255, 255, 255, 0.2),
              0 20px 40px rgba(0, 0, 0, 0.2);
}

/* 动态光效 */
.north img{
  position: relative;
  overflow: hidden;
}

.north img::after{
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.3) 0%, rgba(255,255,255,0) 70%);
  transform: rotate(45deg);
  opacity: 0;
  transition: opacity 0.8s ease;
  pointer-events: none;
  z-index: 2;
}

.north img:hover::after {
  opacity: 1;
  animation: shine 1.5s ease-in-out;
}

@keyframes shine {
  0% { transform: translate(-100%, -100%) rotate(45deg); }
  100% { transform: translate(100%, 100%) rotate(45deg); }
}

/* 为图片容器添加过渡效果 */
.north > div:last-child{
  transition: transform 0.6s cubic-bezier(0.23, 1, 0.32, 1);
  position: relative;
}

.north > div:last-child:hover, .south > div:last-child:hover {
  transform: translateY(-5px);
}
.footer {
    width: 100%;
    height: 220px;
    background-color: #00bcd4;
    color: #fff;
    text-align: center;
    padding: 100px 0;
    font-size: 18px;
}

#backToTop {
      position: fixed;
      bottom: 50px;
      right: 50px;
      width: var(--button-size);
      height: var(--button-size);
      background-color: var(--primary-color);
      color: white;
      border: none;
      border-radius: 50%;
      display: flex;
      justify-content: center;
      align-items: center;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
      opacity: 0;
      visibility: hidden;
      transition: all 0.3s ease;
      z-index: 1000;
      cursor: pointer;
      transform: scale(0);
      transform-origin: center;
      transition: all 0.3s ease;
    }
    
    #backToTop.visible {
      opacity: 1;
      visibility: visible;
      transform: scale(1);
    }
    
    #backToTop:hover {
        background:url(../images/up.png) no-repeat center/cover;
      box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
      transform: scale(1.2);
    }
    
    /* 按钮点击动效 */
    #backToTop:active {
      transform: scale(0.95);
    }
    
    /* 箭头图标 */
    .back-to-top-icon {
      position: relative;
      width: 50px;
      height: 50px;
    }