/* ============================================================
   雀鸣电子 官网样式(工业深色版 · 与安企智能差异化)
   主题色由 js/data.js 中 site.themeColor 动态注入
   设计语言:深色底 · 直角 · 描边 · 切角按钮 · 网格纹理
   ============================================================ */

:root {
  --primary: #e8590c;          /* 默认主题色,会被 data.js 覆盖 */
  --primary-dark: #b23e06;
  --primary-soft: rgba(232, 89, 12, 0.12);
  --text: #e8ecf2;
  --text-light: #9aa7b8;
  --text-faint: #6e7b8f;
  --bg: #0e1116;
  --bg-card: #151a22;
  --bg-gray: #10151c;
  --bg-deep: #080a0e;
  --border: #232b37;
  --radius: 4px;
  --shadow: 0 14px 40px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.5);
  --nav-h: 72px;
  --font-title: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-title);
  color: var(--text);
  line-height: 1.75;
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

/* 全站电路网格纹理 */
body::before {
  content: ""; position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.018) 0 1px, transparent 1px 56px),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.018) 0 1px, transparent 1px 56px);
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; position: relative; z-index: 1; }
::selection { background: var(--primary); color: #0e1116; }

/* ============ 顶部导航(深色) ============ */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(10, 13, 17, 0.72);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all 0.35s ease;
}
.site-header.scrolled {
  background: rgba(8, 10, 14, 0.94);
  border-bottom-color: var(--border);
}
.site-header .container {
  height: 100%; display: flex; align-items: center; justify-content: space-between;
}
.logo { display: flex; align-items: center; gap: 12px; transition: transform 0.3s; }
.logo:hover { transform: scale(1.02); }
.logo img { height: 40px; width: auto; }
.logo-text {
  font-size: 23px; font-weight: 800; color: #fff;
  letter-spacing: 2px;
}
.logo-text span { color: var(--primary); }

.nav-list { display: flex; gap: 4px; }
.nav-list a {
  display: block; padding: 8px 18px; font-size: 15px; color: var(--text-light);
  position: relative; transition: all 0.25s; font-weight: 500;
}
.nav-list a::after {
  content: ""; position: absolute; left: 50%; bottom: 4px;
  width: 0; height: 2px; border-radius: 1px;
  background: var(--primary);
  transform: translateX(-50%); transition: width 0.3s;
}
.nav-list a:hover { color: #fff; }
.nav-list a.active { color: var(--primary); font-weight: 700; }
.nav-list a:hover::after, .nav-list a.active::after { width: 22px; }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span {
  display: block; width: 24px; height: 2px; background: #fff; margin: 5px 0;
  transition: 0.3s;
}
.nav-list.open + .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-list.open + .nav-toggle span:nth-child(2) { opacity: 0; }
.nav-list.open + .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ 页脚(纯黑) ============ */
.site-footer {
  background: var(--bg-deep); color: var(--text-faint);
  padding: 56px 0 24px; margin-top: 100px; position: relative;
  border-top: 1px solid var(--border);
}
.site-footer::before {
  content: ""; position: absolute; top: -1px; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--primary), transparent 65%);
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 48px; padding-bottom: 36px; }
.footer-grid h4 {
  color: #fff; font-size: 14px; margin-bottom: 16px; font-weight: 600;
  letter-spacing: 2px;
}
.footer-grid h4::before { content: "// "; color: var(--primary); }
.footer-grid p { font-size: 14px; margin-bottom: 8px; }
.footer-grid a { font-size: 14px; display: block; margin-bottom: 10px; transition: all 0.25s; }
.footer-grid a:hover { color: #fff; transform: translateX(4px); }
.footer-brand { font-size: 20px; font-weight: 800; color: #fff; margin-bottom: 14px; letter-spacing: 2px; }
.footer-brand span { color: var(--primary); }
.footer-copy {
  border-top: 1px solid rgba(255, 255, 255, 0.06); padding-top: 20px;
  font-size: 13px; text-align: center; color: var(--text-faint);
}
.footer-copy a {
  color: var(--text-faint); text-decoration: none;
}
.footer-copy a:hover {
  color: var(--theme-color); text-decoration: underline;
}

/* ============ 页面横幅(内页顶部 · 左对齐) ============ */
.page-banner {
  margin-top: var(--nav-h);
  background: #0a0d12;
  border-bottom: 1px solid var(--border);
  color: #fff; padding: 72px 0; position: relative; overflow: hidden;
}
.page-banner::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(560px 280px at 82% 24%, rgba(232, 89, 12, 0.14), transparent 62%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.02) 0 1px, transparent 1px 64px);
}
.page-banner h1 {
  font-size: 34px; letter-spacing: 3px; font-weight: 800; position: relative;
}
.page-banner h1::after {
  content: ""; display: inline-block; width: 44px; height: 2px;
  background: var(--primary); margin-left: 16px; vertical-align: middle;
}
.page-banner p { margin-top: 12px; font-size: 15px; color: var(--text-light); position: relative; }
.breadcrumb { margin-top: 14px; font-size: 13px; color: var(--text-faint); position: relative; }
.breadcrumb a:hover { color: var(--primary); }

/* ============ 通用区块(标题左对齐) ============ */
.section { padding: 90px 0; position: relative; }
.section-title {
  text-align: left; margin-bottom: 48px; position: relative; padding-left: 20px;
}
.section-title::before {
  content: ""; position: absolute; left: 0; top: 6px; bottom: 6px;
  width: 3px; background: var(--primary);
}
.title-tag {
  display: block; font-size: 12px; letter-spacing: 4px; font-weight: 600;
  color: var(--primary); margin-bottom: 10px;
}
.title-tag::before { content: "// "; }
.section-title h2 { font-size: 32px; letter-spacing: 2px; font-weight: 800; color: #fff; }
.section-title h2::after {
  content: ""; display: inline-block; width: 44px; height: 2px;
  background: var(--primary); margin-left: 16px; vertical-align: middle;
}
.section-title p { color: var(--text-light); margin-top: 10px; font-size: 15px; }

/* ============ 首页 Hero(静态大标题 + 参数铭牌) ============ */
.hero {
  margin-top: var(--nav-h); position: relative; overflow: hidden;
  background: #0a0d12; min-height: 560px;
  display: flex; align-items: center;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(620px 320px at 78% 28%, rgba(232, 89, 12, 0.16), transparent 62%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.025) 0 1px, transparent 1px 64px),
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.02) 0 1px, transparent 1px 64px);
}
.hero::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 3px;
  background: linear-gradient(90deg, var(--primary), transparent 75%);
}
.hero-grid {
  position: relative; z-index: 2; display: grid; grid-template-columns: 1.4fr 1fr;
  gap: 72px; align-items: center; padding: 90px 24px 96px;
  width: 100%; max-width: 1200px; margin: 0 auto;
}
.hero-eyebrow {
  font-size: 13px; letter-spacing: 5px; color: var(--primary); font-weight: 600;
}
.hero-eyebrow::before { content: "// "; }
.hero-main h2 {
  font-size: 50px; line-height: 1.22; letter-spacing: 2px; font-weight: 800;
  color: #fff; margin: 20px 0 20px;
  opacity: 0; transform: translateY(26px);
  animation: heroUp 0.9s ease 0.2s forwards;
}
.hero-main p {
  font-size: 17px; color: var(--text-light); max-width: 560px;
  margin-bottom: 36px; opacity: 0; transform: translateY(26px);
  animation: heroUp 0.9s ease 0.4s forwards;
}
.hero-main .btn-primary { opacity: 0; transform: translateY(26px); animation: heroUp 0.9s ease 0.6s forwards; }
@keyframes heroUp {
  from { opacity: 0; transform: translateY(26px); }
  to { opacity: 1; transform: none; }
}

/* 右侧铭牌面板 */
.hero-panel {
  position: relative; border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  opacity: 0; transform: translateY(26px);
  animation: heroUp 0.9s ease 0.5s forwards;
}
.hero-panel::before {
  content: ""; position: absolute; top: -1px; left: -1px;
  width: 34px; height: 34px;
  border-top: 3px solid var(--primary); border-left: 3px solid var(--primary);
}
.hero-panel .panel-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 16px 22px; border-bottom: 1px solid var(--border);
  font-size: 12px; letter-spacing: 3px; color: var(--text-faint);
}
.hero-panel .panel-head b { color: var(--primary); font-size: 12px; letter-spacing: 1px; }
.hero-panel .panel-row {
  display: flex; justify-content: space-between; gap: 24px;
  padding: 15px 22px; border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 14px;
}
.hero-panel .panel-row span { color: var(--text-faint); flex-shrink: 0; }
.hero-panel .panel-row b { color: #fff; font-weight: 600; text-align: right; word-break: break-all; }
/* 铭牌底部数据条(3 格) */
.hero-panel .panel-stats {
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.hero-panel .p-stat { padding: 15px 6px 13px; text-align: center; position: relative; }
.hero-panel .p-stat + .p-stat::before {
  content: ""; position: absolute; left: 0; top: 22%; bottom: 22%; width: 1px;
  background: rgba(255, 255, 255, 0.06);
}
.hero-panel .p-stat b {
  display: block; font-size: 22px; font-weight: 800; color: var(--primary);
  line-height: 1.3; letter-spacing: 1px;
}
.hero-panel .p-stat span {
  display: block; font-size: 11px; color: var(--text-faint);
  letter-spacing: 1px; margin-top: 4px;
}
.hero-panel .panel-foot {
  padding: 15px 22px; color: var(--text-light);
  font-size: 13px; letter-spacing: 2px;
}
.hero-panel .panel-foot::before { content: "◆ "; color: var(--primary); }

/* 切角工业按钮 */
.btn-primary {
  display: inline-block; position: relative;
  background: var(--primary); color: #14181f;
  padding: 13px 36px; font-size: 15px;
  font-weight: 700; letter-spacing: 2px; border: none; cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition: all 0.3s;
}
.btn-primary:hover {
  background: #ff7a2e; transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(232, 89, 12, 0.35);
}

/* ============ 业务亮点(直角深色卡) ============ */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 38px 28px; text-align: left; position: relative; overflow: hidden;
  transition: all 0.35s ease;
}
.feature-card::before {
  content: ""; position: absolute; top: 0; left: 0; height: 3px; width: 0;
  background: var(--primary); transition: width 0.45s ease;
}
.feature-card::after {
  content: "+"; position: absolute; right: 16px; top: 8px;
  font-size: 24px; color: var(--text-faint); transition: all 0.35s;
}
.feature-card:hover {
  transform: translateY(-6px); border-color: rgba(232, 89, 12, 0.55);
  box-shadow: var(--shadow);
}
.feature-card:hover::before { width: 100%; }
.feature-card:hover::after { color: var(--primary); transform: rotate(90deg); }
.feature-card .icon {
  width: 62px; height: 62px; margin-bottom: 22px; border-radius: var(--radius);
  background: var(--primary-soft); border: 1px solid rgba(232, 89, 12, 0.4);
  display: flex; align-items: center; justify-content: center;
  transition: all 0.35s;
}
.feature-card:hover .icon {
  background: var(--primary); border-color: var(--primary);
  box-shadow: 0 10px 26px rgba(232, 89, 12, 0.35);
}
.feature-card .icon svg { width: 30px; height: 30px; stroke: var(--primary); transition: stroke 0.35s; }
.feature-card:hover .icon svg { stroke: #14181f; }
.feature-card h3 { font-size: 18px; margin-bottom: 10px; font-weight: 700; color: #fff; }
.feature-card p { font-size: 14px; color: var(--text-light); line-height: 1.8; }

/* ============ 数据统计(黑底橙字) ============ */
.stats {
  background: var(--bg-deep); position: relative; overflow: hidden;
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.stats::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--primary), transparent 70%);
}
.stats-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  text-align: left; position: relative;
}
.stat-item { padding: 10px 26px 10px 0; position: relative; }
.stat-item + .stat-item { border-left: 1px solid var(--border); padding-left: 34px; }
.stat-num {
  font-size: 52px; font-weight: 800; letter-spacing: 1px; color: var(--primary);
  text-shadow: 0 0 30px rgba(232, 89, 12, 0.25);
}
.stat-label { font-size: 13px; color: var(--text-light); margin-top: 6px; letter-spacing: 2px; }

/* ============ 产品卡片(深色描边) ============ */
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.product-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: all 0.35s ease; cursor: pointer;
}
.product-card:hover {
  transform: translateY(-6px); border-color: rgba(232, 89, 12, 0.6);
  box-shadow: var(--shadow);
}
.product-card .thumb {
  height: 200px; background: var(--bg-gray) center/cover no-repeat; position: relative;
  transition: transform 0.5s ease;
}
.product-card .thumb::after {
  content: "+"; position: absolute; right: 12px; bottom: 12px;
  width: 36px; height: 36px; line-height: 36px; text-align: center;
  background: var(--primary); color: #14181f;
  font-size: 22px; font-weight: 700; border-radius: 2px;
  opacity: 0; transform: scale(0.5); visibility: hidden;
  transition: all 0.3s, visibility 0s linear 0.3s;
}
.product-card:hover .thumb::after {
  opacity: 1; transform: scale(1); visibility: visible;
  transition: all 0.3s, visibility 0s;
}
.product-card .thumb-wrap { overflow: hidden; position: relative; }
.product-card:hover .thumb { transform: scale(1.04); }
.product-card .tag {
  position: absolute; top: 12px; right: 12px; z-index: 2;
  background: rgba(10, 13, 17, 0.85); color: var(--primary);
  font-size: 11px; padding: 4px 12px; letter-spacing: 2px;
  border: 1px solid rgba(232, 89, 12, 0.5);
}
.product-card .info {
  padding: 20px 22px 24px; border-top: 1px solid rgba(255, 255, 255, 0.05);
}
.product-card h3 { font-size: 17px; margin-bottom: 8px; font-weight: 700; color: #fff; transition: color 0.25s; }
.product-card:hover h3 { color: var(--primary); }
.product-card p { font-size: 13.5px; color: var(--text-light); line-height: 1.75; }

/* ============ 新闻列表(横向时间线) ============ */
.news-grid { display: grid; grid-template-columns: 1fr; gap: 14px; max-width: 920px; margin: 0 auto; }
.news-card {
  display: flex; align-items: center; gap: 26px;
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 26px; transition: all 0.35s ease; position: relative; overflow: hidden;
}
.news-card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--primary); opacity: 0; transition: opacity 0.35s;
}
.news-card:hover { border-color: rgba(232, 89, 12, 0.5); transform: translateX(6px); }
.news-card:hover::before { opacity: 1; }
.news-card .nc-date {
  flex-shrink: 0; width: 78px; text-align: center;
  border-right: 1px solid var(--border); padding-right: 24px;
}
.news-card .nc-date b { display: block; font-size: 30px; color: var(--primary); font-weight: 800; line-height: 1.1; }
.news-card .nc-date span { font-size: 12px; color: var(--text-faint); letter-spacing: 1px; }
.news-card .nc-body { flex: 1; min-width: 0; }
.news-card .nc-body h3 { font-size: 17px; margin-bottom: 6px; font-weight: 700; color: #fff; transition: color 0.25s; }
.news-card:hover .nc-body h3 { color: var(--primary); }
.news-card .nc-body p {
  font-size: 14px; color: var(--text-light);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.news-card .nc-arrow { flex-shrink: 0; font-size: 22px; color: var(--text-faint); transition: all 0.3s; }
.news-card:hover .nc-arrow { color: var(--primary); transform: translateX(6px); }

/* ============ 产品筛选按钮(下划线式) ============ */
.filter-btn {
  background: transparent; border: none; border-bottom: 2px solid transparent;
  color: var(--text-light); font-size: 15px; font-weight: 600;
  padding: 8px 20px; margin: 0 4px 12px; cursor: pointer;
  letter-spacing: 2px; transition: all 0.3s;
}
.filter-btn:hover { color: #fff; }
.filter-btn.active { color: var(--primary); border-bottom-color: var(--primary); }

/* ============ 关于我们(深色) ============ */
.about-intro {
  max-width: 900px; margin: 0 auto; font-size: 16px; color: var(--text-light);
  text-align: left; line-height: 2.1; background: var(--bg-card);
  border: 1px solid var(--border); border-left: 3px solid var(--primary);
  border-radius: var(--radius); padding: 40px 48px;
}
.timeline { max-width: 760px; margin: 56px auto 0; position: relative; padding-left: 44px; }
.timeline::before {
  content: ""; position: absolute; left: 14px; top: 4px; bottom: 4px; width: 2px;
  background: linear-gradient(180deg, var(--primary), var(--border) 85%);
}
.timeline-item { position: relative; margin-bottom: 36px; }
.timeline-item::before {
  content: ""; position: absolute; left: -37px; top: 12.7px; width: 13px; height: 13px;
  border-radius: 2px; background: var(--bg); border: 2px solid var(--primary);
  transform: rotate(45deg);
}
.timeline-item .year { font-size: 22px; font-weight: 800; color: var(--primary); letter-spacing: 1px; }
.timeline-item p { color: var(--text-light); font-size: 15px; margin-top: 6px; }
.honor-list { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 36px; }
.honor-list li {
  background: transparent; color: var(--text-light);
  padding: 11px 26px; border-radius: var(--radius); font-size: 14px;
  font-weight: 600; border: 1px solid var(--border); letter-spacing: 1px;
  transition: all 0.3s;
}
.honor-list li:hover {
  transform: translateY(-3px); background: var(--primary);
  border-color: var(--primary); color: #14181f; box-shadow: var(--shadow);
}

/* ============ 联系页(深色) ============ */
.contact-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px 44px; }
.contact-item {
  display: flex; gap: 18px; padding: 22px 10px;
  border-bottom: 1px solid var(--border); transition: all 0.3s;
}
.contact-item:hover { background: var(--bg-card); padding-left: 18px; }
.contact-item .c-icon {
  width: 50px; height: 50px; border-radius: var(--radius); flex-shrink: 0;
  background: var(--primary-soft); border: 1px solid rgba(232, 89, 12, 0.4);
  display: flex; align-items: center; justify-content: center; font-size: 21px;
}
.contact-item .c-icon svg { width: 22px; height: 22px; stroke: var(--primary); }
.contact-item h4 { font-size: 15px; margin-bottom: 5px; font-weight: 700; color: #fff; }
.contact-item p { font-size: 14px; color: var(--text-light); }
.contact-map { margin-top: 56px; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); }
.contact-map iframe { width: 100%; height: 400px; border: 0; display: block; filter: grayscale(0.3) invert(0.92) hue-rotate(180deg); }

/* ============ 产品详情弹窗(深色) ============ */
.modal-mask {
  position: fixed; inset: 0; background: rgba(4, 6, 9, 0.78);
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  z-index: 200; display: none; align-items: center; justify-content: center; padding: 20px;
}
.modal-mask.show { display: flex; animation: modalFade 0.3s ease; }
@keyframes modalFade { from { opacity: 0; } to { opacity: 1; } }
.modal-box {
  background: #131820; border: 1px solid var(--border); border-radius: 6px;
  max-width: 720px; width: 100%;
  max-height: 85vh; overflow-y: auto; padding: 40px; position: relative;
  animation: modalIn 0.35s cubic-bezier(0.2, 0.8, 0.3, 1);
  box-shadow: var(--shadow-lg);
}
@keyframes modalIn { from { transform: translateY(30px) scale(0.97); opacity: 0; } to { transform: none; opacity: 1; } }
.modal-box h3 { font-size: 24px; margin-bottom: 14px; font-weight: 800; color: #fff; }
.modal-box .modal-img {
  width: 100%; height: 280px; background: var(--bg-card) center/cover no-repeat;
  border-radius: var(--radius); margin-bottom: 22px;
}
.modal-box p { font-size: 14px; color: var(--text-light); white-space: pre-line; line-height: 1.9; }
.modal-close {
  position: absolute; top: 16px; right: 16px; width: 38px; height: 38px;
  background: var(--bg-card); border: 1px solid var(--border); font-size: 18px;
  cursor: pointer; color: var(--text-light); transition: all 0.3s; z-index: 2;
}
.modal-close:hover { background: var(--primary); color: #14181f; border-color: var(--primary); transform: rotate(90deg); }

/* ============ 新闻详情(深色) ============ */
.news-detail { max-width: 860px; margin: 0 auto; }
.news-detail h1 { font-size: 30px; text-align: center; margin-bottom: 16px; font-weight: 800; color: #fff; line-height: 1.5; }
.news-meta {
  text-align: center; color: var(--text-faint); font-size: 14px; margin-bottom: 40px;
  padding-bottom: 24px; border-bottom: 1px dashed var(--border);
}
.news-body { font-size: 15px; color: var(--text-light); }
.news-body p { margin-bottom: 20px; line-height: 2; }

/* ============ 空状态提示 ============ */
.empty-tip { text-align: center; color: var(--text-light); padding: 70px 0; font-size: 15px; }

/* ============ 返回顶部(方形描边) ============ */
.back-top {
  position: fixed; right: 28px; bottom: 44px; width: 46px; height: 46px;
  background: transparent; border: 1px solid var(--primary); color: var(--primary);
  font-size: 18px; cursor: pointer; border-radius: var(--radius);
  z-index: 90; opacity: 0; pointer-events: none; transition: all 0.35s;
}
.back-top.show { opacity: 1; pointer-events: auto; }
.back-top:hover { background: var(--primary); color: #14181f; }

/* ============ 滚动入场动画 ============ */
.reveal {
  opacity: 0; transform: translateY(36px);
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.2, 0.8, 0.3, 1);
}
.reveal.in { opacity: 1; transform: none; }
.reveal-delay-1 { transition-delay: 0.12s; }
.reveal-delay-2 { transition-delay: 0.24s; }
.reveal-delay-3 { transition-delay: 0.36s; }

/* ============ 可访问性 & 滚动条 ============ */
.btn-primary:focus-visible, .back-top:focus-visible, .nav-toggle:focus-visible,
.filter-btn:focus-visible {
  outline: 2px solid var(--primary); outline-offset: 3px;
}
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-thumb { background: #2a3340; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #3a4553; }

/* ============ 响应式 ============ */
@media (max-width: 900px) {
  .feature-grid, .product-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 30px 0; }
  .stat-item + .stat-item { border-left: none; padding-left: 0; }
  .stat-item:nth-child(3) { border-left: 1px solid var(--border); padding-left: 34px; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .contact-list { grid-template-columns: 1fr; }
  .hero { min-height: auto; }
  .hero-grid { grid-template-columns: 1fr; gap: 44px; padding: 70px 24px 80px; }
  .section { padding: 64px 0; }
  .about-intro { padding: 30px 28px; }
}

@media (max-width: 640px) {
  .nav-list {
    position: fixed; top: var(--nav-h); right: -280px; width: 280px; height: calc(100vh - var(--nav-h));
    background: var(--bg-card); flex-direction: column; padding: 24px; gap: 6px;
    border-left: 1px solid var(--border); transition: right 0.3s ease; z-index: 99;
  }
  .nav-list.open { right: 0; }
  .nav-list a { padding: 14px 18px; font-size: 16px; color: var(--text-light); }
  .nav-toggle { display: block; }
  .feature-grid, .product-grid { grid-template-columns: 1fr; }
  .section { padding: 52px 0; }
  .page-banner { padding: 56px 0; }
  .page-banner h1 { font-size: 26px; }
  .hero-main h2 { font-size: 30px; }
  .stat-num { font-size: 38px; }
  .stat-item:nth-child(3) { border-left: none; padding-left: 0; }
  .section-title h2 { font-size: 24px; }
  .timeline { padding-left: 36px; }
  .news-card { flex-wrap: wrap; gap: 14px; }
  .news-card .nc-date { width: 100%; border-right: none; padding-right: 0; text-align: left; display: flex; align-items: baseline; gap: 10px; }
  .news-card .nc-date b { font-size: 20px; }
}