/* =========================================================
   福州市台江区胜亿智亚科技有限公司 官网样式
   深蓝科技商务风
   ========================================================= */
:root {
  --navy-900: #060d1f;
  --navy-800: #0a1633;
  --navy-700: #0e2148;
  --navy-600: #14306b;
  --blue-500: #1e6fff;
  --cyan-400: #23c4ff;
  --gold-400: #d9a94a;
  --text-main: #1c2434;
  --text-sub: #5a6478;
  --bg-light: #f4f7fc;
  --white: #ffffff;
  --shadow-lg: 0 20px 60px rgba(10, 22, 51, .16);
  --shadow-md: 0 10px 30px rgba(10, 22, 51, .10);
  --radius: 14px;
  --header-h: 76px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-main);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
.container { width: min(1200px, 92%); margin: 0 auto; }
.section { padding: 96px 0; }
.section--dark { background: linear-gradient(160deg, var(--navy-800), var(--navy-900)); color: #dfe8ff; }
.section--light { background: var(--bg-light); }

/* ---------- 通用标题 ---------- */
.sec-head { text-align: center; margin-bottom: 56px; }
.sec-head .en {
  display: inline-block; font-size: 13px; letter-spacing: 4px;
  color: var(--blue-500); text-transform: uppercase; font-weight: 700;
  margin-bottom: 10px;
}
.section--dark .sec-head .en { color: var(--cyan-400); }
.sec-head h2 { font-size: 36px; color: var(--navy-800); letter-spacing: 2px; }
.section--dark .sec-head h2 { color: #fff; }
.sec-head .line {
  width: 56px; height: 4px; margin: 18px auto 0; border-radius: 2px;
  background: linear-gradient(90deg, var(--blue-500), var(--cyan-400));
}
.sec-head p.sub { margin-top: 14px; color: var(--text-sub); font-size: 15px; }
.section--dark .sec-head p.sub { color: #9fb2d8; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 34px; border-radius: 50px; font-size: 15px; font-weight: 600;
  letter-spacing: 1px; cursor: pointer; border: none; transition: all .3s ease;
}
.btn--primary {
  background: linear-gradient(90deg, var(--blue-500), #3f9bff);
  color: #fff; box-shadow: 0 10px 26px rgba(30, 111, 255, .35);
}
.btn--primary:hover { transform: translateY(-3px); box-shadow: 0 16px 34px rgba(30, 111, 255, .45); }
.btn--ghost { background: transparent; color: #fff; border: 1px solid rgba(255, 255, 255, .45); }
.btn--ghost:hover { background: rgba(255, 255, 255, .12); border-color: #fff; }
.btn--dark { background: var(--navy-700); color: #fff; }
.btn--dark:hover { background: var(--navy-600); transform: translateY(-3px); }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 1000; height: var(--header-h);
  transition: all .35s ease;
}
.site-header .bar {
  height: 100%; display: flex; align-items: center; justify-content: space-between;
}
.site-header.scrolled {
  background: rgba(6, 13, 31, .92); backdrop-filter: blur(12px);
  box-shadow: 0 6px 24px rgba(0, 0, 0, .35);
}
.logo { display: flex; align-items: center; gap: 12px; color: #fff; }
.logo-mark {
  width: 42px; height: 42px; border-radius: 10px; flex: none;
  background: linear-gradient(135deg, var(--blue-500), var(--cyan-400));
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 18px; color: #fff; letter-spacing: 1px;
  box-shadow: 0 6px 16px rgba(35, 196, 255, .4);
}
.logo-text { line-height: 1.25; }
.logo-text b { font-size: 17px; letter-spacing: 1px; display: block; }
.logo-text span { font-size: 11px; letter-spacing: 2.5px; color: #8fa4cf; }
.nav { display: flex; gap: 6px; }
.nav a {
  position: relative; padding: 10px 18px; font-size: 15px; color: #cdd9f2;
  letter-spacing: 1px; transition: color .25s;
}
.nav a::after {
  content: ""; position: absolute; left: 18px; right: 18px; bottom: 2px; height: 2px;
  background: linear-gradient(90deg, var(--blue-500), var(--cyan-400));
  transform: scaleX(0); transform-origin: left; transition: transform .3s;
}
.nav a:hover, .nav a.active { color: #fff; }
.nav a:hover::after, .nav a.active::after { transform: scaleX(1); }
.nav-cta {
  margin-left: 10px; padding: 9px 22px !important; border-radius: 30px;
  background: linear-gradient(90deg, var(--blue-500), #3f9bff); color: #fff !important;
}
.nav-cta::after { display: none; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.menu-toggle span { display: block; width: 26px; height: 2px; background: #fff; margin: 6px 0; transition: .3s; }

/* ---------- 首屏横幅 ---------- */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  color: #fff; overflow: hidden; background: var(--navy-900);
}
.hero__bg { position: absolute; inset: 0; }
.hero__bg img { width: 100%; height: 100%; object-fit: cover; opacity: .5; }
.hero__bg::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(6, 13, 31, .96) 15%, rgba(10, 22, 51, .72) 55%, rgba(6, 13, 31, .35));
}
.hero__inner { position: relative; z-index: 2; padding: 140px 0 90px; }
.hero__tag {
  display: inline-flex; align-items: center; gap: 10px; font-size: 14px; letter-spacing: 3px;
  color: var(--cyan-400); margin-bottom: 22px; padding: 8px 18px;
  border: 1px solid rgba(35, 196, 255, .35); border-radius: 40px; background: rgba(35, 196, 255, .08);
}
.hero__tag::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--cyan-400); box-shadow: 0 0 12px var(--cyan-400); }
.hero h1 { font-size: clamp(34px, 5vw, 58px); line-height: 1.25; letter-spacing: 2px; font-weight: 800; }
.hero h1 em { font-style: normal; background: linear-gradient(90deg, #5aa2ff, var(--cyan-400)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { max-width: 640px; margin: 24px 0 40px; font-size: 17px; color: #b9c7e6; }
.hero__actions { display: flex; gap: 18px; flex-wrap: wrap; }
.hero__stats { display: flex; gap: 60px; margin-top: 74px; flex-wrap: wrap; }
.hero__stats .num { font-size: 40px; font-weight: 800; color: #fff; }
.hero__stats .num i { font-style: normal; color: var(--cyan-400); }
.hero__stats .lab { font-size: 14px; color: #8fa4cf; letter-spacing: 2px; margin-top: 4px; }

/* ---------- 页面内banner（二级页通用） ---------- */
.page-banner {
  position: relative; padding: calc(var(--header-h) + 84px) 0 84px;
  color: #fff; background: var(--navy-900); overflow: hidden;
}
.page-banner__bg { position: absolute; inset: 0; }
.page-banner__bg img { width: 100%; height: 100%; object-fit: cover; opacity: .32; }
.page-banner__bg::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(6, 13, 31, .95), rgba(10, 22, 51, .6)); }
.page-banner .container { position: relative; z-index: 2; }
.page-banner h1 { font-size: 42px; letter-spacing: 3px; }
.page-banner .en { color: var(--cyan-400); font-size: 14px; letter-spacing: 5px; text-transform: uppercase; margin-bottom: 12px; display: block; }
.crumb { margin-top: 18px; font-size: 14px; color: #9fb2d8; }
.crumb a { color: #cdd9f2; }
.crumb a:hover { color: #fff; }
.crumb span { margin: 0 8px; color: #5a6b93; }

/* ---------- 首页·关于我们 ---------- */
.about-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 70px; align-items: center; }
.about-media { position: relative; }
.about-media img { border-radius: var(--radius); box-shadow: var(--shadow-lg); }
.about-media::before {
  content: ""; position: absolute; inset: 24px -24px -24px 24px; z-index: -1;
  border-radius: var(--radius); background: linear-gradient(135deg, rgba(30, 111, 255, .18), rgba(35, 196, 255, .10));
}
.about-media .badge {
  position: absolute; right: -18px; bottom: 34px; background: var(--navy-800); color: #fff;
  padding: 20px 26px; border-radius: 12px; box-shadow: var(--shadow-lg); text-align: center;
}
.about-media .badge b { font-size: 30px; color: var(--cyan-400); display: block; }
.about-media .badge span { font-size: 13px; color: #9fb2d8; letter-spacing: 1px; }
.about-body .kicker { color: var(--blue-500); font-weight: 700; letter-spacing: 3px; font-size: 14px; }
.about-body h2 { font-size: 34px; color: var(--navy-800); margin: 12px 0 22px; line-height: 1.4; }
.about-body p { color: var(--text-sub); margin-bottom: 16px; font-size: 15.5px; }
.about-points { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 26px; margin: 30px 0 36px; }
.about-points li { display: flex; gap: 12px; align-items: flex-start; font-size: 15px; }
.about-points .ico {
  flex: none; width: 34px; height: 34px; border-radius: 9px; display: flex; align-items: center; justify-content: center;
  background: rgba(30, 111, 255, .1); color: var(--blue-500); font-size: 17px;
}
.about-points b { color: var(--navy-800); display: block; font-size: 15.5px; }
.about-points small { color: var(--text-sub); font-size: 13px; }

/* ---------- 卡片通用 ---------- */
.cards { display: grid; gap: 28px; }
.cards--3 { grid-template-columns: repeat(3, 1fr); }
.cards--4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 产品卡 ---------- */
.product-card {
  background: #fff; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-md); transition: transform .35s ease, box-shadow .35s ease;
  display: flex; flex-direction: column; border: 1px solid #e8eef8;
}
.product-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); border-color: rgba(30, 111, 255, .35); }
.product-card .thumb { position: relative; aspect-ratio: 1/1; overflow: hidden; background: var(--navy-800); }
.product-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s ease; }
.product-card:hover .thumb img { transform: scale(1.07); }
.product-card .cat {
  position: absolute; left: 14px; top: 14px; font-size: 12px; letter-spacing: 1px;
  background: rgba(6, 13, 31, .78); color: var(--cyan-400); padding: 5px 12px; border-radius: 20px; backdrop-filter: blur(4px);
}
.product-card .info { padding: 22px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.product-card h3 { font-size: 17.5px; color: var(--navy-800); margin-bottom: 6px; }
.product-card .model { font-size: 13px; color: var(--blue-500); letter-spacing: 1px; margin-bottom: 10px; font-weight: 600; }
.product-card .desc { font-size: 14px; color: var(--text-sub); flex: 1;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.product-card .more { margin-top: 16px; font-size: 14px; color: var(--blue-500); font-weight: 600; display: inline-flex; align-items: center; gap: 6px; }
.product-card .more::after { content: "→"; transition: transform .3s; }
.product-card:hover .more::after { transform: translateX(5px); }

/* ---------- 优势 ---------- */
.adv-card {
  background: rgba(255, 255, 255, .04); border: 1px solid rgba(255, 255, 255, .1);
  border-radius: var(--radius); padding: 36px 30px; transition: all .35s;
}
.adv-card:hover { background: rgba(35, 196, 255, .07); border-color: rgba(35, 196, 255, .4); transform: translateY(-6px); }
.adv-card .ico {
  width: 58px; height: 58px; border-radius: 14px; margin-bottom: 22px; font-size: 26px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(30, 111, 255, .35), rgba(35, 196, 255, .2)); color: var(--cyan-400);
}
.adv-card h3 { font-size: 18px; color: #fff; margin-bottom: 10px; letter-spacing: 1px; }
.adv-card p { font-size: 14px; color: #9fb2d8; }

/* ---------- 招商 CTA ---------- */
.cta-band { position: relative; overflow: hidden; border-radius: 18px; }
.cta-band__bg { position: absolute; inset: 0; }
.cta-band__bg img { width: 100%; height: 100%; object-fit: cover; }
.cta-band__bg::after { content: ""; position: absolute; inset: 0; background: linear-gradient(95deg, rgba(6, 13, 31, .94) 20%, rgba(10, 22, 51, .55)); }
.cta-band__inner { position: relative; z-index: 2; padding: 78px 70px; color: #fff; display: flex; align-items: center; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.cta-band h2 { font-size: 32px; letter-spacing: 2px; margin-bottom: 12px; }
.cta-band p { color: #b9c7e6; max-width: 560px; font-size: 15.5px; }

/* ---------- 新闻卡 ---------- */
.news-card {
  display: flex; flex-direction: column; background: #fff; border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-md); border: 1px solid #e8eef8; transition: all .35s;
}
.news-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.news-card .thumb { aspect-ratio: 16/9; overflow: hidden; }
.news-card .thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s; }
.news-card:hover .thumb img { transform: scale(1.06); }
.news-card .info { padding: 24px; display: flex; flex-direction: column; flex: 1; }
.news-card time { font-size: 13px; color: var(--blue-500); letter-spacing: 1px; margin-bottom: 10px; }
.news-card h3 { font-size: 17px; color: var(--navy-800); line-height: 1.55; margin-bottom: 10px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.news-card p { font-size: 14px; color: var(--text-sub); flex: 1;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--navy-900); color: #9fb2d8; padding: 72px 0 0; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.4fr; gap: 50px; padding-bottom: 54px; }
.footer-grid h4 { color: #fff; font-size: 16px; letter-spacing: 2px; margin-bottom: 20px; position: relative; padding-bottom: 12px; }
.footer-grid h4::after { content: ""; position: absolute; left: 0; bottom: 0; width: 28px; height: 2px; background: var(--cyan-400); }
.footer-brand p { margin-top: 18px; line-height: 1.9; }
.footer-links li { margin-bottom: 12px; }
.footer-links a { transition: color .25s, padding-left .25s; }
.footer-links a:hover { color: var(--cyan-400); padding-left: 6px; }
.footer-contact li { display: flex; gap: 10px; margin-bottom: 14px; line-height: 1.8; }
.footer-contact .k { color: var(--cyan-400); flex: none; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .08); padding: 22px 0; text-align: center;
  font-size: 13px; color: #61739c; line-height: 2;
}

/* ---------- 产品中心 ---------- */
.filter-bar { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; margin-bottom: 50px; }
.filter-bar button {
  padding: 10px 26px; border-radius: 40px; border: 1px solid #d7e1f2; background: #fff;
  font-size: 14.5px; color: var(--text-sub); cursor: pointer; transition: all .3s; letter-spacing: 1px;
}
.filter-bar button:hover { border-color: var(--blue-500); color: var(--blue-500); }
.filter-bar button.active {
  background: linear-gradient(90deg, var(--blue-500), #3f9bff); color: #fff; border-color: transparent;
  box-shadow: 0 8px 20px rgba(30, 111, 255, .3);
}

/* ---------- 产品详情 ---------- */
.pd-layout { display: grid; grid-template-columns: 1fr 1.1fr; gap: 64px; align-items: start; }
.pd-gallery { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); position: sticky; top: calc(var(--header-h) + 30px); }
.pd-gallery img { width: 100%; aspect-ratio: 1/1; object-fit: cover; }
.pd-info .cat-tag { display: inline-block; background: rgba(30, 111, 255, .1); color: var(--blue-500); font-size: 13px; padding: 6px 16px; border-radius: 30px; letter-spacing: 1px; margin-bottom: 16px; }
.pd-info h1 { font-size: 32px; color: var(--navy-800); line-height: 1.4; }
.pd-info .model { color: var(--blue-500); font-weight: 700; letter-spacing: 1.5px; margin: 8px 0 20px; }
.pd-info .summary { color: var(--text-sub); font-size: 15.5px; padding-bottom: 26px; border-bottom: 1px dashed #d7e1f2; }
.spec-table { width: 100%; margin: 28px 0; border-collapse: collapse; font-size: 14.5px; }
.spec-table th, .spec-table td { padding: 13px 16px; border: 1px solid #e8eef8; text-align: left; }
.spec-table th { width: 34%; background: var(--bg-light); color: var(--navy-700); font-weight: 600; }
.pd-actions { display: flex; gap: 16px; margin-top: 8px; flex-wrap: wrap; }
.pd-section { margin-top: 70px; }
.pd-section h2 { font-size: 24px; color: var(--navy-800); margin-bottom: 20px; padding-left: 14px; border-left: 4px solid var(--blue-500); }
.pd-section .rich { color: var(--text-sub); font-size: 15.5px; }
.pd-section .rich p { margin-bottom: 14px; }
.pd-section .rich ul { padding-left: 20px; list-style: disc; margin-bottom: 14px; }
.pd-section .rich li { margin-bottom: 6px; }

/* ---------- 招商加盟 ---------- */
.join-policy { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.policy-card {
  position: relative; background: #fff; border-radius: var(--radius); padding: 38px 30px 32px;
  box-shadow: var(--shadow-md); border-top: 4px solid var(--blue-500); transition: all .35s;
}
.policy-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.policy-card .no { position: absolute; top: 22px; right: 26px; font-size: 40px; font-weight: 800; color: rgba(30, 111, 255, .12); }
.policy-card h3 { font-size: 18.5px; color: var(--navy-800); margin-bottom: 12px; }
.policy-card p { font-size: 14.5px; color: var(--text-sub); }
.step-flow { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0; counter-reset: step; }
.step { position: relative; text-align: center; padding: 0 14px; }
.step .dot {
  width: 64px; height: 64px; margin: 0 auto 18px; border-radius: 50%; color: #fff; font-size: 22px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--blue-500), var(--cyan-400));
  box-shadow: 0 10px 24px rgba(30, 111, 255, .35);
}
.step:not(:last-child)::after {
  content: ""; position: absolute; top: 32px; left: calc(50% + 40px); right: calc(-50% + 40px); height: 2px;
  background: repeating-linear-gradient(90deg, rgba(255, 255, 255, .35) 0 8px, transparent 8px 16px);
}
.step h3 { color: #fff; font-size: 16.5px; margin-bottom: 8px; letter-spacing: 1px; }
.step p { font-size: 13.5px; color: #9fb2d8; }
.cond-list { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.cond-list li {
  display: flex; gap: 14px; align-items: flex-start; background: #fff; border-radius: 12px;
  padding: 20px 24px; box-shadow: var(--shadow-md); font-size: 15px; color: var(--text-sub);
}
.cond-list .chk {
  flex: none; width: 26px; height: 26px; border-radius: 50%; color: #fff; font-size: 14px;
  background: linear-gradient(135deg, var(--blue-500), var(--cyan-400));
  display: flex; align-items: center; justify-content: center; margin-top: 2px;
}

/* ---------- 表单 ---------- */
.form-panel { background: #fff; border-radius: 18px; box-shadow: var(--shadow-lg); padding: 48px; }
.form-panel h2 { font-size: 26px; color: var(--navy-800); margin-bottom: 8px; }
.form-panel .tip { color: var(--text-sub); font-size: 14px; margin-bottom: 30px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.form-item { display: flex; flex-direction: column; gap: 8px; }
.form-item.full { grid-column: 1 / -1; }
.form-item label { font-size: 14px; color: var(--navy-700); font-weight: 600; }
.form-item label i { color: #e05252; font-style: normal; margin-left: 2px; }
.form-item input, .form-item select, .form-item textarea {
  padding: 13px 16px; border: 1px solid #d7e1f2; border-radius: 10px; font-size: 15px;
  font-family: inherit; color: var(--text-main); background: #fbfcff; transition: all .25s; outline: none;
}
.form-item input:focus, .form-item select:focus, .form-item textarea:focus {
  border-color: var(--blue-500); background: #fff; box-shadow: 0 0 0 4px rgba(30, 111, 255, .12);
}
.form-item textarea { min-height: 130px; resize: vertical; }
.form-msg { margin-top: 18px; font-size: 14.5px; display: none; }
.form-msg.ok { display: block; color: #1a9c6b; }
.form-msg.err { display: block; color: #e05252; }

/* ---------- 联系页 ---------- */
.contact-layout { display: grid; grid-template-columns: 1fr 1.2fr; gap: 50px; align-items: start; }
.contact-cards { display: grid; gap: 18px; }
.contact-item {
  display: flex; gap: 18px; background: #fff; padding: 24px 26px; border-radius: 14px;
  box-shadow: var(--shadow-md); align-items: flex-start;
}
.contact-item .ico {
  flex: none; width: 50px; height: 50px; border-radius: 12px; font-size: 22px;
  background: linear-gradient(135deg, rgba(30, 111, 255, .16), rgba(35, 196, 255, .12));
  display: flex; align-items: center; justify-content: center; color: var(--blue-500);
}
.contact-item b { color: var(--navy-800); font-size: 16px; display: block; margin-bottom: 4px; }
.contact-item p { font-size: 14px; color: var(--text-sub); line-height: 1.8; }
.map-box { margin-top: 22px; border-radius: 14px; overflow: hidden; box-shadow: var(--shadow-md); }
.map-box img { width: 100%; aspect-ratio: 16/9; object-fit: cover; }

/* ---------- 新闻详情 ---------- */
.article { max-width: 860px; margin: 0 auto; }
.article h1 { font-size: 32px; color: var(--navy-800); line-height: 1.5; margin-bottom: 18px; }
.article .meta { display: flex; gap: 24px; color: var(--text-sub); font-size: 14px; padding-bottom: 26px; border-bottom: 1px solid #e8eef8; margin-bottom: 34px; }
.article .cover { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-md); margin-bottom: 36px; }
.article .body p { margin-bottom: 18px; color: #39435c; font-size: 16px; line-height: 1.95; }
.article .body h3 { color: var(--navy-800); font-size: 20px; margin: 34px 0 14px; }
.article-nav { display: flex; justify-content: space-between; gap: 20px; margin-top: 56px; padding-top: 30px; border-top: 1px solid #e8eef8; }
.article-nav a { color: var(--blue-500); font-size: 15px; }
.article-nav a:hover { text-decoration: underline; }

/* ---------- 动效 ---------- */
.reveal { opacity: 0; transform: translateY(36px); transition: opacity .8s ease, transform .8s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 返回顶部 ---------- */
.to-top {
  position: fixed; right: 26px; bottom: 30px; z-index: 900; width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-500), var(--cyan-400)); color: #fff; border: none; cursor: pointer;
  font-size: 20px; box-shadow: 0 10px 24px rgba(30, 111, 255, .4); opacity: 0; pointer-events: none;
  transition: opacity .3s, transform .3s; transform: translateY(10px);
}
.to-top.show { opacity: 1; pointer-events: auto; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .cards--4 { grid-template-columns: repeat(2, 1fr); }
  .cards--3 { grid-template-columns: repeat(2, 1fr); }
  .about-grid, .pd-layout, .contact-layout { grid-template-columns: 1fr; gap: 46px; }
  .pd-gallery { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .join-policy { grid-template-columns: 1fr 1fr; }
  .step-flow { grid-template-columns: repeat(2, 1fr); gap: 30px; }
  .step:not(:last-child)::after { display: none; }
  .cond-list { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 64px 0; }
  .sec-head h2 { font-size: 27px; }
  .hero__stats { gap: 30px; }
  .cards--4, .cards--3, .join-policy { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .form-panel { padding: 30px 22px; }
  .cta-band__inner { padding: 50px 28px; }
  .page-banner h1 { font-size: 30px; }
  .footer-grid { grid-template-columns: 1fr; gap: 36px; }
  .nav {
    position: fixed; top: var(--header-h); right: 0; left: 0; flex-direction: column; gap: 0;
    background: rgba(6, 13, 31, .98); padding: 14px 0; display: none;
  }
  .nav.open { display: flex; }
  .nav a { padding: 14px 26px; }
  .nav-cta { margin: 10px 26px 4px; text-align: center; }
  .menu-toggle { display: block; }
}