/* ============================================================
 *  KOSO 科索照明官网 — 组件样式
 * ============================================================
 *
 *  本文件按区块组织样式。每个区块的顶部都有注释说明用途。
 *  后期想调整某个区块的样式，可以直接定位到对应区块修改。
 *
 *  区块索引：
 *    1. 通用工具类
 *    2. 容器 / 按钮 / 标题
 *    3. 顶部导航
 *    4. 首页 Hero 轮播
 *    5. 产品 Tab + 卡片轮播
 *    6. 品牌视频区
 *    7. 新闻动态
 *    8. 项目案例（Tab + 灯箱）
 *    9. 品牌数据统计
 *   10. 关于我们
 *   11. 子页通用（产品中心/案例/新闻/资源）
 *   12. 资源下载页
 *   13. 页脚
 *   14. 滚动显现动画
 *   15. 响应式
 * ============================================================ */

/* ============== 1. 通用工具类 ============== */
.wrap { max-width: var(--container-max); margin: 0 auto; padding: 0 var(--container-padding); }
.text-accent { color: var(--color-accent); }
.text-mute   { color: var(--color-text-mute); }
.center      { text-align: center; }

/* ============== 2. 通用区块 / 标题 / 按钮 ============== */
.section { padding: var(--section-padding); position: relative; }
.section.alt { background: var(--color-surface); }
.section-head { text-align: center; margin-bottom: 56px; }
.section-head .eyebrow {
  display: inline-block; color: var(--color-accent);
  font-size: var(--font-size-sm); letter-spacing: var(--letter-spacing-widest);
  text-transform: uppercase; margin-bottom: 12px;
}
.section-head h2 {
  font-size: var(--font-size-3xl); color: var(--color-text);
  letter-spacing: var(--letter-spacing-wider); margin-bottom: 14px;
}
.section-head .en {
  font-size: var(--font-size-sm); color: var(--color-text-mute);
  letter-spacing: var(--letter-spacing-wide); text-transform: uppercase;
}
.section-head::after {
  content: ""; display: block; width: 60px; height: 1px;
  background: var(--color-accent); margin: 24px auto 0;
}

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 32px; border: 1px solid var(--color-accent);
  color: var(--color-accent); background: transparent;
  font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-wide);
  cursor: pointer; transition: all var(--transition-base);
}
.btn:hover { background: var(--color-accent); color: var(--color-bg); }
.btn-ghost { border-color: rgba(255,255,255,.3); color: var(--color-text); }
.btn-ghost:hover { background: rgba(255,255,255,.1); border-color: var(--color-text); }
.btn-light { background: var(--color-accent); border-color: var(--color-accent); color: var(--color-bg); }
.btn-light:hover { background: transparent; color: var(--color-accent); }
.btn .arrow { transition: transform var(--transition-base); }
.btn:hover .arrow { transform: translateX(4px); }

/* ============== 3. 顶部导航（透明悬浮式，仿 cettiga 实测框架） ============== */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--header-height); background: transparent;
  border-bottom: 1px solid transparent;
  transition: background var(--transition-base), border-color var(--transition-base);
}
.site-header.scrolled {
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--color-border);
}
.site-header .wrap { height: 100%; display: flex; align-items: center; justify-content: space-between; }

.brand { display: flex; align-items: center; gap: 14px; }
.brand img { height: 44px; filter: brightness(0) invert(1); }   /* logo 反白，悬浮于深图 */
.site-header.scrolled .brand img { filter: none; }              /* 滚动后恢复原色 */
.brand-text { display: flex; flex-direction: column; line-height: 1.3; }
.brand-text .cn { color: #fff; font-size: var(--font-size-md); font-weight: var(--font-weight-semibold); letter-spacing: var(--letter-spacing-wide); white-space: nowrap; }
.brand-text .tag { color: rgba(255,255,255,.65); font-size: var(--font-size-xs); letter-spacing: var(--letter-spacing-wider); margin-top: 2px; }
.site-header.scrolled .brand-text .cn { color: var(--color-text); }
.site-header.scrolled .brand-text .tag { color: var(--color-text-mute); }

.nav { display: flex; align-items: center; height: 100%; gap: 0; }
.nav a {
  position: relative; height: 100%; padding: 0 14px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: rgba(255,255,255,.85); font-size: var(--font-size-md); font-weight: var(--font-weight-medium);
  letter-spacing: 1px; transition: color var(--transition-fast);
}
.nav a .cn, .nav a .en { white-space: nowrap; }
.nav a .en { display: block; font-size: var(--font-size-xs); color: rgba(255,255,255,.55); margin-top: 2px; letter-spacing: 1px; }
.nav a:hover { color: var(--color-accent); }
.nav a:hover .en { color: var(--color-accent); }
.nav a.active { color: var(--color-accent); }
.nav a.active .en { color: var(--color-accent); opacity: 0.8; }
.nav a.active::after {
  content: ""; position: absolute; bottom: 18px; left: 14px; right: 14px; height: 1px; background: var(--color-accent);
}
/* 滚动后导航项变深色（与原配色统一） */
.site-header.scrolled .nav a { color: var(--color-text-sub); }
.site-header.scrolled .nav a .en { color: var(--color-text-mute); }
.site-header.scrolled .nav a:hover, .site-header.scrolled .nav a.active { color: var(--color-accent); }

/* 右侧工具区（搜索 + 中英切换） */
.header-tools { display: flex; align-items: center; gap: 16px; height: 100%; }
.header-search {
  width: 36px; height: 36px; display: flex; align-items: center; justify-content: center;
  color: rgba(255,255,255,.85); transition: color var(--transition-fast);
}
.header-search:hover { color: var(--color-accent); }
.lang-switch {
  display: flex; align-items: center; gap: 6px; color: rgba(255,255,255,.85);
  font-size: var(--font-size-xs); letter-spacing: 1px;
}
.lang-switch button { padding: 4px 6px; color: inherit; transition: color var(--transition-fast); }
.lang-switch button.active { color: var(--color-accent); }
.lang-switch button:hover { color: var(--color-accent); }
.lang-switch .sep { opacity: .35; }
.site-header.scrolled .header-search { color: var(--color-text-sub); }
.site-header.scrolled .lang-switch { color: var(--color-text-sub); }

.nav-toggle { display: none; width: 32px; height: 32px; padding: 6px; }
.nav-toggle span { display: block; height: 2px; background: var(--color-text); margin: 5px 0; transition: var(--transition-base); }

/* ============== 4. 首页 Hero 轮播（仿 cettiga 实测：左对齐文案 + 左下进度 + 右下箭头） ============== */
.hero-slider {
  position: relative; height: 100vh; min-height: 640px; max-height: 960px;
  overflow: hidden; background: #000;
}
.hero-slide {
  position: absolute; inset: 0; opacity: 0; transition: opacity 1.2s ease-in-out;
  background-size: cover; background-position: center;
}
.hero-slide.active { opacity: 1; z-index: 1; }
/* 文字延迟淡入，避免换帧时两层文字叠加 */
.hero-content { opacity: 0; transition: opacity .5s ease; }
.hero-slide.active .hero-content { opacity: 1; transition: opacity .6s ease .45s; }
/* 左侧加深渐变，让白字可读（图片较暗时也保留氛围感） */
.hero-slide::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(0,0,0,.55) 0%, rgba(0,0,0,.2) 60%, rgba(0,0,0,0) 100%);
  z-index: 1;
}
.hero-content {
  position: absolute; z-index: 2;
  left: 8%; top: 50%; transform: translateY(-50%);
  text-align: left; max-width: 640px;
}
.hero-content .eyebrow {
  display: inline-block; color: var(--color-accent);
  letter-spacing: var(--letter-spacing-widest); font-size: var(--font-size-sm);
  margin-bottom: 18px;
}
.hero-content h1 {
  font-size: var(--font-size-hero); font-weight: var(--font-weight-light);
  letter-spacing: var(--letter-spacing-widest); color: #fff;
  margin-bottom: 24px; line-height: 1.15;
}
.hero-content .sub { font-size: var(--font-size-lg); color: rgba(255,255,255,.85); letter-spacing: var(--letter-spacing-wide); margin-bottom: 36px; }
.hero-content .btn { border-color: rgba(255,255,255,.7); color: #fff; padding: 14px 44px; }
.hero-content .btn:hover { background: #fff; color: #000; border-color: #fff; }
.hero-content .btn-light { background: var(--color-accent); border-color: var(--color-accent); color: #fff; margin-right: 16px; }
.hero-content .btn-light:hover { background: #fff; color: var(--color-accent); border-color: #fff; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

/* 左下进度线 */
.hero-dots {
  position: absolute; left: 8%; bottom: 6%; z-index: 3;
  display: flex; gap: 8px;
}
.hero-dots button {
  width: 32px; height: 2px; background: rgba(255,255,255,.35);
  transition: all var(--transition-base); position: relative; overflow: hidden;
}
.hero-dots button.active { background: rgba(255,255,255,.2); width: 60px; }
.hero-dots button.active::after {
  content: ""; position: absolute; left: 0; top: 0; height: 100%; width: 50%;
  background: var(--color-accent);
  animation: heroDotFill 6s linear forwards;
}
@keyframes heroDotFill { to { width: 100%; } }
.hero-dots button:not(.active)::after { content: none; }

/* 右下双箭头（圆形描边） */
.hero-arrow {
  position: absolute; bottom: 4%; z-index: 3;
  width: 48px; height: 48px; border: 1px solid rgba(255,255,255,.5);
  background: transparent; color: #fff;
  font-size: 18px; display: flex; align-items: center; justify-content: center;
  transition: all var(--transition-base);
}
.hero-arrow:hover { background: var(--color-accent); border-color: var(--color-accent); }
.hero-arrow.prev { right: calc(8% + 56px); }
.hero-arrow.next { right: 8%; }

/* ============== 5. 产品 Tab + 卡片轮播 ==============
 * 风格参考 cettiga.cn：上方大尺寸竖版封面图（4:5），
 * 下方双行文字（产品名 / 型号 EN 编号）。
 * 想调整封面比例：改 .product-card .media 的 aspect-ratio
 * 想改成 1:1 正方形：aspect-ratio: 1/1
 * 想改成 16:9 横屏：aspect-ratio: 16/9
 */
.product-section { padding: var(--section-padding); }
.product-tabs {
  display: flex; justify-content: center; gap: 0; margin-bottom: 48px;
  border-bottom: 1px solid var(--color-border);
}
.product-tabs button {
  padding: 16px 36px; color: var(--color-text-mute); font-size: var(--font-size-md);
  letter-spacing: var(--letter-spacing-wide); position: relative;
  transition: color var(--transition-fast);
}
.product-tabs button .en { display: block; font-size: var(--font-size-xs); margin-top: 2px; }
.product-tabs button:hover { color: var(--color-text); }
.product-tabs button.active { color: var(--color-accent); }
.product-tabs button.active::after {
  content: ""; position: absolute; left: 36px; right: 36px; bottom: -1px; height: 2px; background: var(--color-accent);
}

.product-carousel-wrap { position: relative; overflow: hidden; }
.product-carousel { display: flex; gap: 24px; transition: transform 0.5s ease; }
.product-card {
  flex: 0 0 calc((100% - 24px * 3) / 4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  overflow: hidden; cursor: pointer;
  transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}
.product-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 14px 40px rgba(0,0,0,.35);
}
.product-card .media {
  position: relative;
  aspect-ratio: 4 / 5;       /* ▼ 竖版产品封面（cettiga 风格） */
  overflow: hidden; background: #000;
}
.product-card .media img,
.product-card .media video {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform .8s ease, opacity .4s ease;
}
.product-card:hover .media img { transform: scale(1.06); }

/* 播放提示图标（hover 时浮现） */
.product-card .play-icon {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(180deg, transparent 50%, rgba(0,0,0,.55) 100%);
  opacity: 0; transition: opacity var(--transition-base);
  pointer-events: none;
}
.product-card .play-icon::before {
  content: ""; width: 56px; height: 56px; border-radius: 50%;
  border: 1.5px solid rgba(255,255,255,.85);
  background: rgba(0,0,0,.25) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'><path d='M8 5v14l11-7z'/></svg>") center / 22px no-repeat;
  backdrop-filter: blur(6px);
  transition: transform var(--transition-base);
}
.product-card:hover .play-icon { opacity: 1; }
.product-card:hover .play-icon::before { transform: scale(1.08); }

/* 左上角分类小标 */
.product-card .badge {
  position: absolute; top: 14px; left: 14px;
  background: rgba(10,10,10,.65); color: var(--color-accent);
  font-size: var(--font-size-xs); padding: 4px 10px;
  letter-spacing: var(--letter-spacing-wide);
  border: 1px solid rgba(201,163,90,.35);
  backdrop-filter: blur(8px);
}

/* 卡片下方双行文字 */
.product-card .body {
  padding: 22px 22px 26px;
  border-top: 1px solid rgba(201,163,90,.12);
  text-align: left;
}
.product-card .body h4 {
  color: var(--color-text); font-size: var(--font-size-md);
  font-weight: 500; letter-spacing: 1px; margin-bottom: 8px;
}
.product-card .body .model {
  color: var(--color-accent); font-size: var(--font-size-xs);
  letter-spacing: 2px; font-family: "Courier New", monospace;
  text-transform: uppercase;
}

/* 网格版（产品中心页） */
.product-grid {
  display: grid; gap: 24px;
  grid-template-columns: repeat(4, 1fr);
}
.product-grid .product-card { flex: initial; }

.carousel-arrow {
  position: absolute; top: 50%; transform: translateY(-50%); z-index: 5;
  width: 48px; height: 48px; background: rgba(0,0,0,.6); color: var(--color-text);
  border: 1px solid var(--color-border); display: flex; align-items: center; justify-content: center;
  font-size: 18px; transition: var(--transition-base);
}
.carousel-arrow:hover { background: var(--color-accent); color: var(--color-bg); border-color: var(--color-accent); }
.carousel-arrow.prev { left: 16px; }
.carousel-arrow.next { right: 16px; }

/* ============== 6. 品牌视频区 ============== */
.brand-video { position: relative; padding: 120px 0; overflow: hidden; }
.brand-video::before {
  content: ""; position: absolute; inset: 0; background: rgba(0,0,0,.6); z-index: 1;
}
.brand-video .bg-video {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: 0;
}
.brand-video .inner {
  position: relative; z-index: 2; max-width: 720px; margin: 0 auto; text-align: center;
}
.brand-video .quote {
  font-size: var(--font-size-xl); color: var(--color-text);
  letter-spacing: var(--letter-spacing-wide); line-height: 1.7;
  position: relative; padding: 0 40px;
}
.brand-video .quote::before, .brand-video .quote::after {
  content: "\""; position: absolute; color: var(--color-accent);
  font-size: 60px; line-height: 1; opacity: 0.5;
}
.brand-video .quote::before { top: -20px; left: 0; }
.brand-video .quote::after  { bottom: -40px; right: 0; }
.brand-video .desc { color: var(--color-text-sub); font-size: var(--font-size-md); margin-top: 32px; }
.brand-video .actions { margin-top: 40px; display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

/* ============== 7. 新闻动态 ============== */
.news-section { padding: var(--section-padding); background: var(--color-surface); }
.news-list {
  max-width: 980px; margin: 0 auto;
}
.news-item {
  display: grid; grid-template-columns: 160px 1fr 200px; gap: 32px;
  padding: 28px 0; border-bottom: 1px solid var(--color-divider);
  align-items: center; transition: var(--transition-base);
}
.news-item:hover { padding-left: 16px; }
.news-item .date { color: var(--color-accent); font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-wide); font-weight: var(--font-weight-medium); }
.news-item .title { color: var(--color-text); font-size: var(--font-size-lg); font-weight: var(--font-weight-medium); line-height: 1.5; }
.news-item .summary { color: var(--color-text-mute); font-size: var(--font-size-sm); line-height: 1.7; }
.news-item:hover .title { color: var(--color-accent); }
.news-item .cover { aspect-ratio: 16/10; overflow: hidden; background: var(--color-surface-2); }
.news-item .cover img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.news-item:hover .cover img { transform: scale(1.05); }

/* 新闻详情页 */
.news-detail { max-width: 800px; margin: 0 auto; }
.news-detail .meta { color: var(--color-text-mute); margin-bottom: 32px; }
.news-detail .body { color: var(--color-text-sub); font-size: var(--font-size-md); line-height: 2; }
.news-detail .body p { margin-bottom: 16px; }
.news-detail .cover-img { width: 100%; aspect-ratio: 16/9; object-fit: cover; margin-bottom: 32px; }

/* ============== 8. 项目案例 ============== */
.projects-section { padding: var(--section-padding); }
.project-tabs {
  display: flex; justify-content: center; gap: 48px; margin-bottom: 48px;
}
.project-tabs button {
  padding: 8px 0; color: var(--color-text-mute); font-size: var(--font-size-md);
  letter-spacing: var(--letter-spacing-wide); position: relative;
  transition: color var(--transition-fast);
}
.project-tabs button::after {
  content: ""; position: absolute; bottom: 0; left: 50%; width: 0; height: 1px;
  background: var(--color-accent); transition: var(--transition-base);
  transform: translateX(-50%);
}
.project-tabs button:hover, .project-tabs button.active { color: var(--color-accent); }
.project-tabs button.active::after { width: 100%; }

.project-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.project-card {
  position: relative; aspect-ratio: 4/5; overflow: hidden; cursor: pointer;
  background: var(--color-surface);
}
.project-card img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
.project-card:hover img { transform: scale(1.08); }
.project-card .info {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 24px;
  background: linear-gradient(to top, rgba(0,0,0,.85) 0%, transparent 100%);
  z-index: 2;
}
.project-card .info h4 { color: var(--color-text); font-size: var(--font-size-md); margin-bottom: 4px; }
.project-card .info .meta { color: var(--color-accent); font-size: var(--font-size-xs); letter-spacing: var(--letter-spacing-wide); }
.project-card::after {
  content: "查看"; position: absolute; top: 20px; right: 20px; z-index: 2;
  background: var(--color-accent); color: var(--color-bg);
  padding: 4px 12px; font-size: var(--font-size-xs); letter-spacing: var(--letter-spacing-wide);
  opacity: 0; transition: var(--transition-base);
}
.project-card:hover::after { opacity: 1; }

/* 案例页全屏网格 */
.cases-page { padding: 60px 0; }
.cases-toolbar {
  display: flex; justify-content: space-between; align-items: center;
  max-width: var(--container-max); margin: 0 auto 32px; padding: 0 var(--container-padding);
  flex-wrap: wrap; gap: 16px;
}
.cases-filter { display: flex; gap: 8px; }
.cases-filter button {
  padding: 8px 24px; border: 1px solid var(--color-border); color: var(--color-text-sub);
  font-size: var(--font-size-sm); letter-spacing: var(--letter-spacing-wide); transition: var(--transition-fast);
}
.cases-filter button:hover { border-color: var(--color-accent); color: var(--color-accent); }
.cases-filter button.active { background: var(--color-accent); border-color: var(--color-accent); color: var(--color-bg); }

/* 灯箱 */
.lightbox {
  position: fixed; inset: 0; background: rgba(0,0,0,.92); z-index: 1000;
  display: none; align-items: center; justify-content: center;
}
.lightbox.show { display: flex; }
.lightbox img { max-width: 86%; max-height: 86vh; box-shadow: var(--shadow-lg); }
.lightbox .lb-name {
  position: absolute; bottom: 32px; left: 0; right: 0; text-align: center;
  color: var(--color-text); font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-wide);
}
.lightbox .lb-close {
  position: absolute; top: 24px; right: 32px; color: var(--color-text);
  font-size: 36px; cursor: pointer; line-height: 1;
}
.lightbox .lb-nav {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 56px; height: 56px; color: var(--color-text);
  background: rgba(255,255,255,.1); display: flex; align-items: center; justify-content: center;
  font-size: 20px; cursor: pointer; transition: var(--transition-fast);
}
.lightbox .lb-nav:hover { background: var(--color-accent); color: var(--color-bg); }
.lightbox .lb-nav.prev { left: 24px; }
.lightbox .lb-nav.next { right: 24px; }

/* ============== 9. 品牌数据统计 ============== */
.stats-section {
  padding: 80px 0; background: var(--color-surface);
  border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border);
}
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.stat-item { text-align: center; }
.stat-item .num {
  font-size: var(--font-size-4xl); color: var(--color-accent);
  font-weight: var(--font-weight-light); letter-spacing: 1px;
  font-family: var(--font-family-en);
}
.stat-item .label { color: var(--color-text-sub); font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-wide); margin-top: 8px; }

/* ============== 10. 关于我们 ============== */
.about-grid {
  display: grid; grid-template-columns: 1fr 1.4fr; gap: 56px; align-items: start;
}
.about-card {
  background: var(--color-surface); padding: 40px;
  border: 1px solid var(--color-border);
}
.about-card h3 { color: var(--color-text); font-size: var(--font-size-xl); margin-bottom: 24px; letter-spacing: var(--letter-spacing-wide); }
.about-card dl { display: grid; gap: 16px; }
.about-card dt { color: var(--color-accent); font-size: var(--font-size-sm); letter-spacing: var(--letter-spacing-wide); }
.about-card dd { color: var(--color-text-sub); font-size: var(--font-size-md); margin-bottom: 16px; padding-bottom: 16px; border-bottom: 1px dashed var(--color-divider); }
.about-card dd:last-child { border-bottom: none; }
.about-map { aspect-ratio: 16/10; background: var(--color-surface); border: 1px solid var(--color-border); overflow: hidden; }
.about-map iframe { width: 100%; height: 100%; border: 0; filter: invert(.92) hue-rotate(180deg); }

/* 发展历程 */
.timeline-section { padding: var(--section-padding); background: var(--color-surface); }
.timeline { max-width: 900px; margin: 0 auto; position: relative; padding-left: 0; }
.timeline::before {
  content: ""; position: absolute; left: 50%; top: 0; bottom: 0; width: 1px;
  background: var(--color-divider);
}
.tl-item {
  display: grid; grid-template-columns: 1fr 80px 1fr; gap: 0;
  margin-bottom: 48px; align-items: center; position: relative;
}
.tl-year {
  font-size: var(--font-size-2xl); color: var(--color-accent); font-weight: var(--font-weight-light);
  text-align: right; padding-right: 32px;
}
.tl-item:nth-child(even) .tl-year { text-align: left; padding-right: 0; padding-left: 32px; order: 3; }
.tl-dot {
  width: 12px; height: 12px; border-radius: 50%; background: var(--color-accent);
  margin: 0 auto; position: relative; z-index: 2;
  box-shadow: 0 0 0 4px var(--color-bg), 0 0 0 5px var(--color-accent);
}
.tl-content {
  background: var(--color-surface-2); border: 1px solid var(--color-border);
  padding: 20px 24px; margin-left: 32px;
}
.tl-item:nth-child(even) .tl-content { margin-left: 0; margin-right: 32px; order: 1; }
.tl-content h4 { color: var(--color-text); margin-bottom: 6px; font-size: var(--font-size-md); }
.tl-content p { color: var(--color-text-mute); font-size: var(--font-size-sm); margin: 0; }

/* ============== 11. 子页通用（产品中心/案例/新闻） ============== */
.page-hero {
  position: relative; height: 48vh; min-height: 360px; max-height: 520px;
  display: flex; align-items: center; justify-content: center;
  margin-top: var(--header-height); overflow: hidden;
}
.page-hero img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: 0; }
.page-hero::before { content: ""; position: absolute; inset: 0; background: rgba(0,0,0,.55); z-index: 1; }
.page-hero .page-title {
  position: relative; z-index: 2; text-align: center; color: var(--color-text);
}
.page-hero .page-title h1 {
  font-size: var(--font-size-4xl); letter-spacing: var(--letter-spacing-wider); margin-bottom: 12px;
  font-weight: var(--font-weight-light);
}
.page-hero .page-title .en { color: var(--color-accent); font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-widest); }

.breadcrumb {
  display: flex; gap: 8px; align-items: center; padding: 20px 0;
  font-size: var(--font-size-sm); color: var(--color-text-mute);
  border-bottom: 1px solid var(--color-border); margin-bottom: 32px;
}
.breadcrumb a { color: var(--color-text-mute); }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb .sep { color: var(--color-text-faint); }

/* ============== 12. 资源下载页 ============== */
.resources-page { padding: 60px 0; }
.resource-toolbar { display: flex; gap: 12px; margin-bottom: 32px; flex-wrap: wrap; }
.resource-toolbar button {
  padding: 8px 20px; border: 1px solid var(--color-border); color: var(--color-text-sub);
  font-size: var(--font-size-sm); letter-spacing: var(--letter-spacing-wide); transition: var(--transition-fast);
}
.resource-toolbar button:hover { border-color: var(--color-accent); color: var(--color-accent); }
.resource-toolbar button.active { background: var(--color-accent); border-color: var(--color-accent); color: var(--color-bg); }

.resource-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.resource-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  padding: 32px; transition: var(--transition-base);
  display: flex; flex-direction: column; gap: 16px;
}
.resource-card:hover { border-color: var(--color-accent); transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.resource-card .icon {
  width: 56px; height: 56px; background: var(--color-surface-2);
  display: flex; align-items: center; justify-content: center;
  font-size: 32px; border: 1px solid var(--color-border);
}
.resource-card .cat { color: var(--color-accent); font-size: var(--font-size-xs); letter-spacing: var(--letter-spacing-widest); }
.resource-card h3 { color: var(--color-text); font-size: var(--font-size-lg); line-height: 1.5; }
.resource-card .desc { color: var(--color-text-mute); font-size: var(--font-size-sm); }
.resource-card .meta { display: flex; gap: 16px; color: var(--color-text-faint); font-size: var(--font-size-xs); }
.resource-card .actions { margin-top: auto; padding-top: 8px; }
.resource-card .actions .btn { width: 100%; justify-content: center; }

.empty-state {
  text-align: center; padding: 80px 20px; color: var(--color-text-mute);
}
.empty-state .icon { font-size: 64px; opacity: 0.3; margin-bottom: 16px; }

/* ============== 13. 页脚 ============== */
.site-footer {
  background: #050505; border-top: 1px solid var(--color-border);
  padding: 60px 0 24px; color: var(--color-text-mute);
}
.footer-top {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 48px;
  padding-bottom: 40px; border-bottom: 1px solid var(--color-divider);
}
.footer-brand p { color: var(--color-text-mute); margin-top: 16px; line-height: 1.9; font-size: var(--font-size-sm); }
.footer-col h5 { color: var(--color-text); margin-bottom: 16px; font-size: var(--font-size-md); letter-spacing: var(--letter-spacing-wide); }
.footer-col li { padding: 6px 0; font-size: var(--font-size-sm); }
.footer-col a:hover { color: var(--color-accent); }
.footer-bottom {
  padding-top: 24px; display: flex; justify-content: space-between; align-items: center;
  font-size: var(--font-size-xs); color: var(--color-text-faint);
}
.footer-bottom .social { display: flex; gap: 16px; }
.footer-bottom .social a:hover { color: var(--color-accent); }

/* ============== 14. 滚动显现动画 ============== */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ============== 15. 响应式 ============== */
@media (max-width: 1080px) {
  .product-card { flex: 0 0 calc((100% - 24px * 2) / 3); }
  .product-grid { grid-template-columns: repeat(3, 1fr); }
  .project-grid { grid-template-columns: repeat(3, 1fr); }
  .resource-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 860px) {
  :root { --header-height: 64px; --section-padding: 64px 0; --font-size-hero: 40px; --font-size-4xl: 30px; }
  .brand img { height: 36px; }
  .brand-text .cn { font-size: var(--font-size-sm); }
  .brand-text .tag { display: none; }
  .nav { position: fixed; top: 64px; right: 0; bottom: 0; width: 240px; background: var(--color-bg); flex-direction: column; align-items: stretch; padding: 16px 0; border-left: 1px solid var(--color-border); transform: translateX(100%); transition: var(--transition-base); overflow-y: auto; height: calc(100vh - 64px); }
  .nav.open { transform: translateX(0); }
  .nav a { height: 56px; padding: 0 24px; align-items: flex-start; }
  .nav a.active::after { display: none; }
  .nav-toggle { display: flex; flex-direction: column; justify-content: center; }
  .header-tools { display: none; }
  .nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .hero-slider { height: 70vh; min-height: 400px; }
  .product-card { flex: 0 0 calc((100% - 24px) / 2); }
  .product-tabs { flex-wrap: wrap; gap: 0; }
  .product-tabs button { padding: 12px 18px; flex: 1 1 33%; }
  .product-tabs button.active::after { left: 18px; right: 18px; }
  .project-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
  .news-item { grid-template-columns: 1fr; gap: 12px; }
  .news-item .cover { display: none; }
  .about-grid { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
  .timeline::before { left: 16px; }
  .tl-item, .tl-item:nth-child(even) { grid-template-columns: 32px 1fr; }
  .tl-year, .tl-item:nth-child(even) .tl-year { text-align: left; padding: 0 0 8px 8px; order: 0; font-size: var(--font-size-xl); }
  .tl-dot { order: 0; margin-left: 0; }
  .tl-content, .tl-item:nth-child(even) .tl-content { margin: 0; order: 2; }
  .resource-grid { grid-template-columns: 1fr; }
  .hero-arrow { display: none; }
  .page-hero { height: 36vh; min-height: 260px; }
}
@media (max-width: 540px) {
  .product-card { flex: 0 0 100%; }
  .product-grid { grid-template-columns: 1fr; }
  .project-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .footer-top { grid-template-columns: 1fr; }
}