/* ==========================================================================
   恒信检测 — 企业宣传官网 全局样式
   配色：深蓝 + 青碧（区别于参考站的珊瑚红）
   ========================================================================== */

:root {
  --primary: #1e4f8f;
  --primary-dark: #143a6b;
  --primary-light: #eaf1f9;
  --teal: #1b7a8c;
  --accent: #e9a13b;
  --navy: #0e2338;
  --navy-2: #16324f;
  --text: #333;
  --text-light: #777;
  --bg-alt: #f3f6fa;
  --border: #e3e9f2;
  --white: #fff;
  --shadow: 0 12px 30px rgba(14, 35, 56, 0.1);
  --serif: Georgia, "Times New Roman", "Songti SC", "SimSun", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color 0.25s; }
ul { list-style: none; }

.container { width: min(1200px, 92%); margin: 0 auto; }

/* ---------------- 顶部信息条 ---------------- */
.topbar {
  background: var(--navy);
  color: rgba(255, 255, 255, 0.75);
  font-size: 13px;
  height: 40px;
  display: flex;
  align-items: center;
}
.topbar .container {
  display: flex;
  justify-content: flex-end;
  align-items: center;
}
.topbar .hotline { display: flex; align-items: center; gap: 8px; }
.topbar .hotline svg { width: 14px; height: 14px; }
.topbar .hotline strong {
  color: var(--accent);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.5px;
  font-family: var(--serif);
}

/* ---------------- 主导航 ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  transition: box-shadow 0.3s;
}
.site-header.scrolled { box-shadow: 0 6px 20px rgba(14, 35, 56, 0.12); }
.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 84px;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo img { width: 50px; height: 50px; object-fit: contain; border-radius: 6px; }
.logo .name { line-height: 1.25; }
.logo .cn {
  display: block;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 3px;
}
.logo .en {
  display: block;
  font-size: 11px;
  color: #9aa7b5;
  letter-spacing: 2.5px;
}

.main-nav { display: flex; align-items: center; }
.main-nav a {
  position: relative;
  padding: 8px 26px;
  font-size: 15px;
  color: #444;
  border-right: 1px solid var(--border);
}
.main-nav a:last-child { border-right: none; padding-right: 0; }
.main-nav a::after {
  content: "";
  position: absolute;
  left: 26px;
  right: 26px;
  bottom: -4px;
  height: 2px;
  background: var(--primary);
  transform: scaleX(0);
  transition: transform 0.3s;
}
.main-nav a:hover, .main-nav a.active { color: var(--primary); }
.main-nav a:hover::after, .main-nav a.active::after { transform: scaleX(1); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--primary);
  margin: 5px 0;
  transition: 0.3s;
}

/* ---------------- Banner 轮播 ---------------- */
.banner { position: relative; height: min(680px, 82vh); overflow: hidden; background: var(--navy); }
.banner-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.9s ease;
  display: flex;
  align-items: center;
}
.banner-slide.current { opacity: 1; z-index: 1; }
.banner-slide.s1 { background: linear-gradient(118deg, #12356b 0%, #1e4f8f 52%, #1b7a8c 100%); }
.banner-slide.s2 { background: linear-gradient(118deg, #0e2338 0%, #16324f 55%, #1e4f8f 100%); }
.banner-slide.s3 { background: linear-gradient(118deg, #124b66 0%, #1b7a8c 55%, #2a6fb8 100%); }
.banner-deco {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.banner-inner { position: relative; }
.banner-copy {
  margin-left: auto;
  max-width: 560px;
  text-align: right;
  color: var(--white);
  transform: translateY(18px);
  opacity: 0;
  transition: 0.9s ease 0.25s;
}
.banner-slide.current .banner-copy { transform: none; opacity: 1; }
.banner-copy h2 {
  font-size: 44px;
  font-weight: 700;
  letter-spacing: 4px;
  line-height: 1.3;
  text-shadow: 0 4px 18px rgba(0, 0, 0, 0.25);
}
.banner-copy h2 em { font-style: normal; color: var(--accent); }
.banner-copy p {
  margin: 18px 0 30px;
  font-size: 16px;
  color: rgba(255, 255, 255, 0.85);
}
.banner .arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 5;
  width: 46px;
  height: 46px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.16);
  color: var(--white);
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.3s;
}
.banner .arrow:hover { background: var(--primary); }
.banner .arrow.prev { left: 26px; }
.banner .arrow.next { right: 26px; }
.banner-dots {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 26px;
  z-index: 5;
  display: flex;
  justify-content: center;
  gap: 10px;
}
.banner-dots button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: rgba(255, 255, 255, 0.45);
  cursor: pointer;
  transition: 0.3s;
  padding: 0;
}
.banner-dots button.current { background: var(--accent); width: 26px; border-radius: 5px; }

/* ---------------- 通用板块 ---------------- */
.section { padding: 90px 0; }
.section.alt { background: var(--bg-alt); }
.sec-head { margin-bottom: 46px; }
.sec-head .en {
  font-family: var(--serif);
  font-size: 36px;
  font-weight: 700;
  color: #222;
  letter-spacing: 1px;
}
.sec-head .cn {
  margin-top: 6px;
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 1px;
}
.sec-head.center { text-align: center; }

.btn {
  display: inline-block;
  padding: 12px 38px;
  border-radius: 999px;
  font-size: 14px;
  letter-spacing: 2px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: 0.3s;
}
.btn-primary { background: var(--primary); color: var(--white); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 10px 20px rgba(30, 79, 143, 0.3); }
.btn-white { background: var(--white); color: var(--primary); }
.btn-white:hover { background: var(--accent); color: var(--white); transform: translateY(-2px); }
.btn-ghost { border-color: var(--primary); color: var(--primary); background: transparent; }
.btn-ghost:hover { background: var(--primary); color: var(--white); }
.btn-center { text-align: center; margin-top: 46px; }

/* ---------------- 首页：公司简介 ---------------- */
.about-grid { display: grid; grid-template-columns: 5fr 6fr; gap: 56px; align-items: center; }
.about-grid .lead-name { font-size: 20px; font-weight: 700; color: var(--primary); }
.about-grid .lead-name span { display: block; font-size: 13px; font-weight: 400; color: #98a5b3; letter-spacing: 0.5px; }
.about-grid p { margin-top: 18px; color: var(--text-light); text-align: justify; }
.about-grid .btn { margin-top: 30px; }
.dir-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.dir-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: 0.35s;
}
.dir-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.dir-card .media { overflow: hidden; aspect-ratio: 16 / 9.4; }
.dir-card .media img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.dir-card:hover .media img { transform: scale(1.06); }
.dir-card figcaption {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 13px 18px;
  background: #f7f9fc;
  font-size: 15px;
  font-weight: 600;
}
.dir-card figcaption .num { font-family: var(--serif); font-weight: 700; color: var(--accent); }

/* ---------------- 数据 band ---------------- */
.stats {
  background: linear-gradient(120deg, var(--navy) 0%, var(--navy-2) 60%, #1d4a63 100%);
  color: var(--white);
  padding: 64px 0;
}
.stats .container { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.stat .num {
  font-family: var(--serif);
  font-size: 46px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.1;
}
.stat .num i { font-style: normal; font-size: 24px; margin-left: 4px; }
.stat .label { margin-top: 6px; font-size: 14px; color: rgba(255, 255, 255, 0.72); letter-spacing: 1px; }

/* ---------------- 服务优势 ---------------- */
.adv-grid { display: grid; grid-template-columns: 5fr 6fr; gap: 56px; align-items: center; }
.adv-grid p { color: var(--text-light); margin-bottom: 14px; text-align: justify; }
.adv-grid .slogan { color: var(--primary); font-size: 17px; font-weight: 700; }
.adv-grid .btn { margin-top: 18px; }
.adv-list { display: flex; flex-direction: column; gap: 34px; }
.adv-item { display: flex; align-items: center; gap: 22px; }
.adv-item .icon {
  flex: none;
  width: 60px;
  height: 60px;
  border: 2px solid var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  background: var(--white);
}
.adv-item .icon svg { width: 26px; height: 26px; }
.adv-item h4 { font-size: 17px; color: #222; }
.adv-item h4 b { color: var(--primary); }
.adv-item p { font-size: 14px; color: var(--text-light); margin-top: 4px; max-width: 330px; }
.adv-item .keyword {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 26px;
  font-weight: 700;
  color: #222;
  letter-spacing: 2px;
  white-space: nowrap;
}
.adv-item .keyword svg { width: 24px; height: 24px; color: var(--accent); }

/* ---------------- 服务列表 ---------------- */
.svc-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* ---------------- CTA / 在线预约 ---------------- */
.cta {
  background: linear-gradient(115deg, #16437e 0%, #1e4f8f 45%, #1b7a8c 100%);
  color: var(--white);
  padding: 80px 0;
}
.cta-grid { display: grid; grid-template-columns: 6fr 5fr; gap: 60px; align-items: center; }
.cta h3 { font-size: 30px; letter-spacing: 2px; }
.cta .sub { margin: 10px 0 28px; color: rgba(255, 255, 255, 0.8); }
.demo-form .row { margin-bottom: 16px; }
.demo-form input, .demo-form select, .demo-form textarea {
  width: 100%;
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.08);
  color: var(--white);
  font-size: 14px;
  font-family: var(--sans);
  outline: none;
  transition: border 0.3s, background 0.3s;
}
.demo-form textarea { border-radius: 14px; min-height: 110px; resize: vertical; }
.demo-form input::placeholder, .demo-form textarea::placeholder { color: rgba(255, 255, 255, 0.65); }
.demo-form input:focus, .demo-form select:focus, .demo-form textarea:focus {
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.14);
}
.demo-form select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, rgba(255,255,255,.8) 50%), linear-gradient(135deg, rgba(255,255,255,.8) 50%, transparent 50%); background-position: calc(100% - 22px) 55%, calc(100% - 16px) 55%; background-size: 6px 6px; background-repeat: no-repeat; }
.demo-form select option { color: #333; }
.demo-form .btn { margin-top: 8px; }
.form-tip { margin-top: 12px; font-size: 13px; color: rgba(255, 255, 255, 0.65); }
.cta-right { text-align: right; }
.cta-right .phone-line { display: flex; align-items: center; justify-content: flex-end; gap: 16px; }
.cta-right .phone-badge {
  width: 62px;
  height: 62px;
  border: 2px solid rgba(255, 255, 255, 0.85);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}
.cta-right .phone-badge svg { width: 28px; height: 28px; }
.cta-right .phone-label { font-size: 14px; color: rgba(255, 255, 255, 0.8); }
.cta-right .phone-num { font-family: var(--serif); font-size: 34px; font-weight: 700; letter-spacing: 1px; white-space: nowrap; }
.cta-right p { margin-top: 22px; color: rgba(255, 255, 255, 0.82); }

/* ---------------- 新闻 ---------------- */
.news-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.news-item {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
  background: var(--white);
  padding: 20px 26px;
  border: 1px solid var(--border);
  transition: 0.3s;
}
.news-item svg { width: 16px; height: 16px; color: #b8c2cd; flex: none; }
.news-item .t {
  flex: 1;
  font-size: 15px;
  color: #333;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}
.news-item:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: transparent; }
.news-item:hover .t { color: var(--primary); }
.news-item .date { font-size: 13px; color: #9aa7b5; font-family: var(--serif); }

/* 新闻列表页 */
.news-page-list { display: flex; flex-direction: column; gap: 18px; max-width: 880px; margin: 0 auto; }
.news-row {
  display: flex;
  gap: 24px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px 28px;
  transition: 0.3s;
}
.news-row:hover { box-shadow: var(--shadow); transform: translateY(-3px); border-color: transparent; }
.news-row .datebox {
  flex: none;
  width: 76px;
  text-align: center;
  border-right: 1px solid var(--border);
  padding-right: 20px;
}
.news-row .datebox .d { display: block; font-family: var(--serif); font-size: 32px; font-weight: 700; color: var(--primary); line-height: 1.1; }
.news-row .datebox .ym { display: block; font-size: 12px; color: #9aa7b5; }
.news-row h3 { font-size: 16px; color: #222; transition: color 0.25s; }
.news-row:hover h3 { color: var(--primary); }
.news-row p { margin-top: 8px; font-size: 14px; color: var(--text-light); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.pager { display: flex; justify-content: center; gap: 10px; margin-top: 44px; }
.pager a {
  min-width: 38px;
  height: 38px;
  padding: 0 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  color: var(--text-light);
}
.pager a.current, .pager a:hover { background: var(--primary); border-color: var(--primary); color: var(--white); }

/* ---------------- 子页 Banner ---------------- */
.page-hero {
  background: linear-gradient(118deg, #12356b 0%, #1e4f8f 55%, #1b7a8c 100%);
  color: var(--white);
  padding: 74px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-hero .en { font-family: var(--serif); font-size: 15px; letter-spacing: 4px; color: rgba(255, 255, 255, 0.65); text-transform: uppercase; }
.page-hero h1 { margin-top: 8px; font-size: 34px; letter-spacing: 6px; }
.page-hero .crumb { margin-top: 14px; font-size: 13px; color: rgba(255, 255, 255, 0.75); }
.page-hero .crumb a:hover { color: var(--accent); }

/* ---------------- 关于我们 ---------------- */
.about-detail { display: grid; grid-template-columns: 7fr 5fr; gap: 56px; align-items: center; }
.about-detail h3 { font-size: 22px; color: #222; margin-bottom: 16px; }
.about-detail h3 b { color: var(--primary); }
.about-detail p { color: var(--text-light); text-align: justify; margin-bottom: 12px; }
.about-detail img { border-radius: 10px; box-shadow: var(--shadow); }

.culture-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.culture-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-top: 3px solid var(--primary);
  border-radius: 10px;
  padding: 34px 28px;
  text-align: center;
  transition: 0.3s;
}
.culture-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.culture-card .icon {
  width: 62px;
  height: 62px;
  margin: 0 auto 18px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}
.culture-card .icon svg { width: 28px; height: 28px; }
.culture-card h4 { font-size: 17px; color: #222; letter-spacing: 2px; }
.culture-card p { margin-top: 10px; font-size: 14px; color: var(--text-light); }

.timeline { position: relative; max-width: 760px; margin: 0 auto; padding-left: 26px; }
.timeline::before { content: ""; position: absolute; left: 0; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.tl-item { position: relative; padding: 0 0 34px 26px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 7px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--accent);
}
.tl-item .year { font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--primary); }
.tl-item h4 { margin-top: 2px; font-size: 16px; color: #222; }
.tl-item p { font-size: 14px; color: var(--text-light); margin-top: 4px; }

.cert-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.cert-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: 0.3s;
}
.cert-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.cert-card img { aspect-ratio: 4 / 3; object-fit: cover; width: 100%; }
.cert-card figcaption { padding: 13px 16px; font-size: 14px; text-align: center; color: #444; }

/* ---------------- 服务/产品卡片 ---------------- */
.svc-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: 0.35s;
}
.svc-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.svc-card .media { overflow: hidden; aspect-ratio: 16 / 10; }
.svc-card .media img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.svc-card:hover .media img { transform: scale(1.06); }
.svc-card .body { padding: 20px 22px 24px; }
.svc-card h4 { font-size: 16px; color: #222; transition: color 0.25s; }
.svc-card:hover h4 { color: var(--primary); }
.svc-card p { margin-top: 8px; font-size: 13.5px; color: var(--text-light); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }

/* ---------------- 联系我们 ---------------- */
.contact-cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.contact-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 30px 24px;
  text-align: center;
  transition: 0.3s;
}
.contact-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.contact-card .icon {
  width: 58px;
  height: 58px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
}
.contact-card .icon svg { width: 26px; height: 26px; }
.contact-card h4 { font-size: 15px; color: #999; font-weight: 400; letter-spacing: 2px; }
.contact-card p { margin-top: 6px; font-size: 15px; color: #222; font-weight: 600; }
.contact-wrap { display: grid; grid-template-columns: 6fr 5fr; gap: 40px; }
.contact-form-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 36px;
  box-shadow: var(--shadow);
}
.contact-form-card h3 { font-size: 20px; color: #222; margin-bottom: 22px; }
.contact-form-card h3 b { color: var(--primary); }
.contact-form-card .grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form-card input, .contact-form-card textarea {
  width: 100%;
  padding: 12px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: var(--sans);
  color: var(--text);
  outline: none;
  margin-bottom: 16px;
  transition: border 0.3s;
}
.contact-form-card input:focus, .contact-form-card textarea:focus { border-color: var(--primary); }
.contact-form-card textarea { min-height: 120px; resize: vertical; }
.map-note { margin-top: 14px; font-size: 13px; color: #9aa7b5; text-align: center; }
.qr-card { text-align: center; }
.qr-card img { width: 150px; margin: 0 auto; background: var(--white); border-radius: 8px; padding: 8px; border: 1px solid var(--border); }
.qr-card p { margin-top: 10px; font-size: 13px; color: #8b98a6; }

/* ---------------- 页脚 ---------------- */
.site-footer { background: var(--navy); color: rgba(255, 255, 255, 0.65); }
.footer-top { display: grid; grid-template-columns: 5fr 3fr 6fr; gap: 44px; padding: 68px 0 52px; }
.footer-top .logo img { background: var(--white); border-radius: 8px; padding: 5px; }
.footer-top .logo .cn { color: var(--white); }
.footer-top .logo .en { color: rgba(255, 255, 255, 0.4); }
.footer-top p { margin-top: 18px; font-size: 13.5px; line-height: 1.9; }
.footer-top h4 { color: var(--white); font-size: 16px; letter-spacing: 2px; margin-bottom: 20px; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { font-size: 14px; color: rgba(255, 255, 255, 0.62); }
.footer-links a:hover { color: var(--accent); }
.footer-contact li { display: flex; gap: 10px; margin-bottom: 12px; font-size: 13.5px; }
.footer-contact svg { width: 16px; height: 16px; flex: none; margin-top: 4px; color: var(--accent); }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.08); padding: 20px 0; }
.footer-bottom .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.42);
}
.footer-bottom a { color: rgba(255, 255, 255, 0.42); }
.footer-bottom a:hover { color: var(--accent); }

/* ---------------- 回到顶部 ---------------- */
.back-top {
  position: fixed;
  right: 26px;
  bottom: 34px;
  z-index: 90;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 8px;
  background: var(--navy);
  color: var(--white);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: 0.35s;
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top:hover { background: var(--primary); }
.back-top svg { width: 20px; height: 20px; }

/* ---------------- 入场动画 ---------------- */
[data-reveal] { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s ease; }
[data-reveal].revealed { opacity: 1; transform: none; }

/* ---------------- 表单提示 toast ---------------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 40px;
  transform: translate(-50%, 16px);
  z-index: 200;
  background: var(--navy);
  color: var(--white);
  font-size: 14px;
  padding: 12px 26px;
  border-radius: 999px;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transition: 0.35s;
}
.toast.show { opacity: 1; visibility: visible; transform: translate(-50%, 0); }

/* ---------------- 响应式 ---------------- */
@media (max-width: 992px) {
  .topbar .clock { display: none; }
  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    align-items: stretch;
    box-shadow: 0 16px 30px rgba(14, 35, 56, 0.15);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
  }
  .main-nav.open { max-height: 420px; }
  .main-nav a { border-right: none; border-bottom: 1px solid var(--border); padding: 14px 5%; }
  .main-nav a::after { display: none; }
  .nav-toggle { display: block; }
  .site-header .container { height: 70px; }
  .banner { height: 520px; }
  .banner-copy h2 { font-size: 32px; }
  .about-grid, .adv-grid, .cta-grid, .about-detail, .contact-wrap { grid-template-columns: 1fr; gap: 40px; }
  .svc-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .cert-grid, .contact-cards { grid-template-columns: repeat(2, 1fr); }
  .culture-grid { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 36px; }
  .adv-item .keyword { font-size: 20px; }
  .section { padding: 64px 0; }
}

@media (max-width: 640px) {
  .banner { height: 460px; }
  .banner-copy { max-width: 100%; text-align: left; }
  .banner .arrow { display: none; }
  .banner-copy h2 { font-size: 27px; letter-spacing: 2px; }
  .sec-head .en { font-size: 28px; }
  .stats .container { grid-template-columns: 1fr 1fr; gap: 30px 10px; }
  .stat .num { font-size: 34px; }
  .dir-grid, .news-cols, .svc-grid, .grid-3, .cert-grid, .contact-cards, .contact-form-card .grid2 { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr; }
  .news-row { flex-direction: column; gap: 10px; }
  .news-row .datebox { border-right: none; border-bottom: 1px solid var(--border); padding: 0 0 10px; width: auto; text-align: left; display: flex; align-items: baseline; gap: 8px; }
  .cta-right { text-align: left; }
  .cta-right .phone-line { justify-content: flex-start; }
  .cta-right .phone-num { font-size: 24px; }
  .page-hero h1 { font-size: 26px; letter-spacing: 3px; }
}