/* 基础样式 */
:root {
  --header-height: 80px;
  --transition-speed: 0.3s;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
}

/* 头部导航样式 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  z-index: 100;
}

.header-inner {
  max-width: 1440px;
  height: 100%;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px; /* 减小logo和菜单的间距 */
}

.logo-section {
  flex-shrink: 0;
}

.logo-img {
  height: 20px;
}

.nav-menu {
  display: flex;
  gap: 20px; /* 减小菜单项间距 */
  flex-wrap: wrap; /* 允许菜单项换行 */
  align-items: center;
}

.nav-item {
  color: #fff;
  text-decoration: none;
  font-size: 16px;
  padding: 5px 10px;
  white-space: nowrap;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 20px;
  cursor: pointer;
  z-index: 1000;
}

.mobile-menu-btn span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: #fff;
  transition: all 0.3s ease;
}

/* 移动端菜单 */
.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 80%;
  height: 100vh;
  background: rgba(0, 0, 0, 0.95);
  backdrop-filter: blur(10px);
  z-index: 999;
  transition: right 0.3s ease;
}

.mobile-menu.active {
  right: 0;
}

.mobile-menu-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.mobile-logo {
  height: 30px;
}

.mobile-close-btn {
  color: #fff;
  font-size: 30px;
  cursor: pointer;
  padding: 10px;
}

.mobile-nav {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.mobile-nav-item {
  color: #fff;
  text-decoration: none;
  font-size: 18px;
  padding: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.3s ease;
}

.mobile-nav-item:hover {
  background: rgba(255, 255, 255, 0.1);
}

.bf-banner {
  width: 100%;
  margin-top: 80px;
  position: relative;
}

.banner-image-container {
  width: 100%;
  height: 728px; /* 可以根据需要调整高度 */
  position: relative;
}

.bf-banner-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* PC端显示 */
.switch-mobile-banner {
  display: none;
}

.six-major-bases {
  padding: 60px 0;
  background: linear-gradient(135deg, #f5f9ff 0%, #e8f1ff 100%);
}

.six-major-bases .model-title {
  margin-bottom: 40px;
}

.six-major-bases .content-wrapper {
  display: flex;
  gap: 40px;
  align-items: center;
}

.six-major-bases .base-img {
  flex: 0 0 50%;
  max-width: 50%;
  height: 400px;
}

.six-major-bases .base-img .img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 8px;
}

.six-major-bases .desc {
  flex: 0 0 50%;
  max-width: 50%;
  line-height: 1.8;
}

.major-centers {
  padding: 80px 0;
  background: #fff;
}

.major-centers .model-title {
  margin-bottom: 50px;
}

.major-centers .content-wrapper {
  display: flex;
  gap: 60px;
  align-items: center;
}

.major-centers .image-section {
  flex: 0 0 45%;
  height: 400px;
}

.major-centers .image-section .img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.major-centers .text-section {
  flex: 0 0 55%;
}

.major-centers .title {
  margin-bottom: 20px;
  color: #333;
  position: relative;
  padding-left: 15px;
}

.major-centers .title:before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 20px;
  background: #1890ff;
  border-radius: 2px;
}

.major-centers .description {
  line-height: 1.8;
  color: #666;
}

.production-line {
  padding: 80px 0;
  background: linear-gradient(to bottom, #fff, #f8fafc);
}

.production-line .model-title {
  margin-bottom: 60px;
}

.production-line .items-wrapper {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  max-width: 1200px;
  margin: 0 auto;
}

.production-line .item {
  position: relative;
  height: 280px;
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.production-line .item:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.production-line .icon {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  transition: all 0.3s ease;
}

.production-line .item:hover .icon {
  transform: scale(1.1);
}

.production-line .content {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 30px;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0));
  color: #fff;
}

.production-line .title {
  font-size: 20px;
  margin-bottom: 10px;
  font-weight: 500;
}

.production-line .text {
  font-size: 15px;
  line-height: 1.6;
  opacity: 0.9;
}


/* 移动端适配 */

@media screen and (max-width: 992px) {
  .production-line {
    padding: 60px 0;
  }

  .production-line .items-wrapper {
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    padding: 0 20px;
  }
}

@media screen and (max-width: 768px) {
  .banner-image-container {
    height: 400px; /* 移动端banner高度 */
  }
  
  .switch-pc-banner {
    display: none;
  }
  
  .switch-mobile-banner {
    display: block;
  }

  .six-major-bases {
    padding: 40px 0;
  }

  .six-major-bases .content-wrapper {
    flex-direction: column;
    gap: 20px;
  }

  .six-major-bases .base-img,
  .six-major-bases .desc {
    flex: 0 0 100%;
    max-width: 100%;
  }

  .six-major-bases .base-img {
    height: 300px;
  }

  .major-centers {
    padding: 40px 0;
  }

  .major-centers .content-wrapper {
    flex-direction: column;
    gap: 30px;
  }

  .major-centers .image-section {
    flex: 0 0 100%;
    height: 250px;
  }

  .major-centers .text-section {
    flex: 0 0 100%;
  }
  
  .major-centers .title {
    font-size: 20px;
  }

  
}

@media screen and (max-width: 576px) {
  .production-line {
    padding: 40px 0;
  }

  .production-line .items-wrapper {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .production-line .item {
    height: 240px;
  }

  .production-line .content {
    padding: 20px;
  }

  .production-line .title {
    font-size: 18px;
  }
}

@media (max-width: 768px) {
  .header-inner {
    padding: 0 15px;
    gap: 20px;
  }

  .nav-menu {
      display: none; /* 隐藏原导航 */
    }
  
    .mobile-menu-btn {
      display: flex; /* 显示移动端菜单按钮 */
    }
  
    .header-inner {
      justify-content: space-between;
    }

}

  
@media (max-width: 480px) {
  .header {
    min-height: var(--header-height);
  }

  .header-inner {
    flex-wrap: wrap;
    padding: 10px;
  }

}

@media (max-width: 890px) {
  /* 导航相关 */
  .nav-menu {
    display: none; /* 隐藏原导航 */
  }

  .mobile-menu-btn {
    display: flex; /* 显示移动端菜单按钮 */
  }

  .header-inner {
    justify-content: space-between;
  }

}
  /* 菜单打开时的按钮样式 */
.mobile-menu-btn.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }
  
  .mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
  }
  
  .mobile-menu-btn.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }