:root {
  --navy: #0E2A47;
  --navy-deep: #081C31;
  --teal: #00A9C4;
  --teal-text: #0B7285;
  --orange: #FF6A13;
  --orange-text: #C2410C;
  --amber: #F5A623;
  --gray-bg: #F5F7FA;
  --gray-line: #E3E8EF;
  --gray-meta: #8A95A5;
  --text: #4A5568;
  --text-strong: #22303F;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Alibaba PuHuiTi 3.0", -apple-system, "Segoe UI", sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.75;
  font-size: 15px;
}

a { color: var(--teal-text); text-decoration: none; }
a:hover { color: var(--orange-text); }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* 顶部信息条（电话 / 邮箱 / 微信，全站 NAP 一致） */
.utilitybar {
  background: var(--gray-bg);
  border-bottom: 1px solid var(--gray-line);
  font-size: 12.5px;
  color: var(--gray-meta);
}
.utilitybar .wrap {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 20px;
  height: 34px;
}

/* 顶部导航 */
header {
  background: #fff;
  border-bottom: 1px solid var(--gray-line);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo { display: flex; align-items: center; }
.logo img { height: 30px; width: auto; display: block; }
nav ul {
  list-style: none;
  display: flex;
  gap: 26px;
  margin: 0;
  padding: 0;
}
nav a {
  color: var(--text-strong);
  font-size: 14.5px;
}
nav a:hover, nav a.active { color: var(--orange-text); }
.nav-toggle { display: none; }
.nav-cb { display: none; }
.wrap.nav { position: relative; }
.nav-toggle { position: relative; width: 44px; height: 44px; margin-left: auto; cursor: pointer; }
.nav-toggle span, .nav-toggle::before, .nav-toggle::after {
  content: ''; position: absolute; left: 12px; right: 12px; height: 2px;
  background: var(--navy); border-radius: 2px; transition: .25s;
}
.nav-toggle span { top: 21px; }
.nav-toggle::before { top: 14px; }
.nav-toggle::after { top: 28px; }
.nav-cb:checked ~ .nav-toggle::before { top: 21px; transform: rotate(45deg); }
.nav-cb:checked ~ .nav-toggle::after { top: 21px; transform: rotate(-45deg); }
.nav-cb:checked ~ .nav-toggle span { opacity: 0; }

/* 产品中心下拉 */
nav > ul > li { position: relative; }
nav ul li.has-sub > a::after {
  content: '';
  display: inline-block;
  width: 5px; height: 5px;
  margin-left: 5px;
  vertical-align: 2px;
  border-right: 1.4px solid currentColor;
  border-bottom: 1.4px solid currentColor;
  transform: rotate(45deg);
  opacity: .65;
}
nav ul ul.sub {
  display: none;
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  min-width: 158px;
  margin: 0;
  padding: 6px 0;
  gap: 0;
  background: #fff;
  border: 1px solid var(--gray-line);
  border-radius: 5px;
  box-shadow: 0 10px 26px rgba(11, 42, 71, .14);
}
nav ul ul.sub::before {
  content: '';
  position: absolute;
  left: 0; right: 0; top: -14px; height: 14px;   /* 消除与父项之间的悬停空隙 */
}
nav ul li.has-sub:hover > ul.sub,
nav ul li.has-sub:focus-within > ul.sub { display: block; }
nav ul ul.sub a {
  display: block;
  padding: 8px 18px;
  font-size: 14px;
  white-space: nowrap;
  color: var(--text-strong);
}
nav ul ul.sub a:hover { background: #F2F6FA; color: var(--orange-text); }

/* 语言切换 */
.lang {
  font-size: 12.5px;
  border: 1px solid var(--gray-line);
  border-radius: 3px;
  padding: 5px 11px;
  color: var(--text-strong);
  margin-left: 16px;
  letter-spacing: 0.5px;
  white-space: nowrap;
}
.lang:hover { border-color: var(--orange); color: var(--orange-text); }
.nav-en nav ul { gap: 15px; }
.nav-en nav a { font-size: 13.5px; }

/* Hero */
.hero {
  background: linear-gradient(120deg, var(--navy-deep) 0%, var(--navy) 60%, #123A5E 100%);
  color: #fff;
  padding: 72px 0 64px;
}
.hero-kicker {
  display: inline-block;
  color: #6ED0E0;
  border: 1px solid rgba(110,208,224,0.4);
  border-radius: 3px;
  padding: 4px 14px;
  font-size: 14px;
  letter-spacing: 2px;
  margin: 0 0 18px;
}
.hero h1 {
  font-size: 34px;
  line-height: 1.35;
  margin: 0 0 16px;
  font-weight: 700;
}
.hero p {
  font-size: 16px;
  color: #C4D3E2;
  margin: 0 0 28px;
  max-width: 680px;
}
.hero-cap {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 26px;
}
.hero-cap span {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.16);
  padding: 7px 14px;
  border-radius: 4px;
  font-size: 13.5px;
  color: #E4EDF5;
}
.btn {
  display: inline-block;
  background: var(--orange);
  color: #fff;
  padding: 12px 28px;
  border-radius: 4px;
  font-size: 15px;
  font-weight: 500;
}
.btn:hover { background: #E85D0C; color: #fff; }
.btn-ghost {
  border: 1px solid rgba(255,255,255,0.35);
  padding: 12px 24px;
  border-radius: 4px;
  color: #fff;
  margin-left: 12px;
}

/* 通用区块 */
section { padding: 56px 0; }
section.alt { background: var(--gray-bg); }
h2 {
  font-size: 24px;
  color: var(--navy);
  margin: 0 0 8px;
  font-weight: 700;
}
.sub {
  color: var(--gray-meta);
  font-size: 14px;
  margin: 0 0 28px;
}
h3 {
  font-size: 17px;
  color: var(--navy);
  margin: 32px 0 10px;
}

/* 卡片 */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: #fff;
  border: 1px solid var(--gray-line);
  border-radius: 6px;
  padding: 24px;
}
section.alt .card { background: #fff; }
.card h4 {
  margin: 0 0 10px;
  font-size: 17px;
  color: var(--navy);
}
.card .pos {
  color: var(--teal-text);
  font-size: 14px;
  margin: 0 0 14px;
}
.card ul {
  margin: 0;
  padding-left: 18px;
  font-size: 14.5px;
}
.card ul li { margin-bottom: 7px; }
.tags { margin-top: 14px; }
.tags span {
  display: inline-block;
  background: var(--gray-bg);
  border: 1px solid var(--gray-line);
  color: var(--text-strong);
  font-size: 12.5px;
  padding: 3px 9px;
  border-radius: 3px;
  margin: 0 6px 6px 0;
}

/* 表格 */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  margin: 14px 0;
}
th {
  background: var(--navy);
  color: #fff;
  text-align: left;
  padding: 11px 14px;
  font-weight: 500;
}
td {
  border-bottom: 1px solid var(--gray-line);
  padding: 11px 14px;
}
tbody tr:nth-child(even) { background: var(--gray-bg); }
.tw { overflow-x: auto; }
.tw table { min-width: 720px; }
.note {
  font-size: 13px;
  color: var(--gray-meta);
  margin-top: 8px;
}

/* 步骤 */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.step {
  border-top: 3px solid var(--teal);
  padding-top: 14px;
}
.step b { display: block; color: var(--navy); font-size: 15.5px; margin-bottom: 6px; }
.step span { font-size: 13.5px; color: var(--gray-meta); }

/* FAQ */
.faq-item {
  border-bottom: 1px solid var(--gray-line);
  padding: 18px 0;
}
.faq-item:last-child { border-bottom: none; }
.faq-q {
  font-weight: 600;
  color: var(--navy);
  font-size: 15.5px;
  margin: 0 0 8px;
}
.faq-a { margin: 0; font-size: 14.5px; }

/* 列表资质 */
.qual { list-style: none; padding: 0; margin: 0; }
.qual li {
  padding: 10px 0 10px 22px;
  border-bottom: 1px dashed var(--gray-line);
  position: relative;
  font-size: 14.5px;
}
.qual li::before {
  content: "";
  position: absolute;
  left: 4px; top: 19px;
  width: 6px; height: 6px;
  background: var(--teal);
  border-radius: 50%;
}

/* 提示框 */
.callout {
  background: var(--gray-bg);
  border-left: 3px solid var(--teal);
  padding: 14px 18px;
  font-size: 14px;
  border-radius: 0 4px 4px 0;
}
.badge-tech {
  display: inline-block;
  background: var(--amber);
  color: #fff;
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 2px;
  margin-left: 8px;
}

/* CTA */
.cta {
  background: var(--navy);
  color: #fff;
  padding: 48px 0;
  text-align: center;
}
.cta h2 { color: #fff; }
.cta p { color: #C4D3E2; margin: 0 0 22px; }

/* 页脚 */
footer {
  background: var(--navy-deep);
  color: #9FB2C6;
  padding: 40px 0 24px;
  font-size: 13.5px;
}
.foot-grid { display: grid; grid-template-columns: 1.7fr 1fr 1fr 1.2fr; gap: 28px; }
.foot-grid.fg3 { grid-template-columns: 2fr 1fr 1fr; }
footer h5 { color: #fff; font-size: 14.5px; margin: 0 0 12px; font-weight: 600; }
footer ul { list-style: none; padding: 0; margin: 0; }
footer li { margin-bottom: 7px; }
footer a { color: #9FB2C6; }
footer a:hover { color: #fff; }
.foot-slogan {
  color: #C4D3E2;
  font-size: 14px;
  letter-spacing: 1px;
  margin: 0 0 16px;
}

/* 品牌标识区块 */
.brand-block {
  display: flex;
  align-items: center;
  gap: 28px;
  background: #fff;
  border: 1px solid var(--gray-line);
  border-radius: 6px;
  padding: 26px 28px;
  margin: 24px 0 8px;
}
.brand-block img { height: 52px; display: block; flex: 0 0 auto; }
.brand-line {
  margin: 0 0 6px;
  color: var(--navy);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 1px;
}
.brand-line.alt { color: var(--orange-text); }
.brand-block .note { margin: 10px 0 0; }

/* 页脚合规声明：出口管制提示 + 隐私政策入口（法务审查 P0-06 / P0-08） */
.export-note {
  margin: 0 0 14px;
  padding: 12px 14px;
  font-size: 12px;
  line-height: 1.75;
  color: #8FA3B8;
  background: rgba(255, 255, 255, .05);
  border-left: 2px solid rgba(255, 255, 255, .16);
}
.export-note strong { color: #C4D3E2; }
.foot-legal { margin: 0 0 6px; font-size: 12.5px; }
.foot-legal a { color: #C4D3E2; text-decoration: underline; }

.copy {
  border-top: 1px solid rgba(255,255,255,0.1);
  margin-top: 28px;
  padding-top: 18px;
  font-size: 12.5px;
  color: #7C8FA3;
}

/* 面包屑 */
.crumb { font-size: 13px; color: var(--gray-meta); padding: 14px 0 0; }
.crumb a { color: var(--gray-meta); }

/* 产品销售栏位 */
.series-h {
  font-size: 18px;
  color: var(--navy);
  margin: 34px 0 6px;
  font-weight: 700;
}
.tbl-cap {
  font-size: 15px;
  color: var(--navy);
  font-weight: 600;
  margin: 24px 0 8px;
  padding-left: 10px;
  border-left: 3px solid var(--teal);
}
table.prod td:first-child { font-weight: 600; color: var(--navy); }
table.prod th:first-child { min-width: 108px; }
.btn-line {
  display: inline-block;
  border: 1px solid var(--teal);
  color: var(--teal-text);
  padding: 11px 22px;
  border-radius: 4px;
  font-size: 14.5px;
}
.btn-line:hover { background: var(--teal); color: #fff; }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.quote-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.quote-grid .card { padding: 18px 20px; }
.quote-grid b { color: var(--navy); display: block; margin-bottom: 4px; font-size: 14.5px; }
.quote-grid span { font-size: 13.5px; color: var(--gray-meta); }

/* 技术文章区 */
.art-item {
  border-bottom: 1px solid var(--gray-line);
  padding: 24px 0;
}
.art-item:first-child { padding-top: 0; }
.art-item h3 { margin: 0 0 8px; font-size: 18px; }
.art-item h3 a { color: var(--navy); }
.art-item h3 a:hover { color: var(--orange-text); }
.art-meta { font-size: 12.5px; color: var(--gray-meta); margin: 0 0 8px; }
.art-item p { margin: 0; font-size: 14.5px; }

.article { max-width: 820px; }
.article p { margin: 0 0 15px; }
.article h2 { font-size: 21px; margin: 38px 0 12px; }
.article h3 { font-size: 17px; margin: 26px 0 8px; }
.article ul, .article ol { margin: 0 0 16px; padding-left: 22px; }
.article li { margin-bottom: 8px; }
.article .lead { font-size: 16px; color: var(--text-strong); }
.article .concl {
  background: var(--gray-bg);
  border-left: 3px solid var(--teal);
  padding: 12px 18px;
  margin: 0 0 16px;
  border-radius: 0 4px 4px 0;
}
.article .mistake {
  background: #FFF8F3;
  border-left: 3px solid var(--orange);
  padding: 12px 18px;
  margin: 0 0 12px;
  border-radius: 0 4px 4px 0;
}
.article .formula {
  background: var(--navy-deep);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.3px;
  text-align: center;
  padding: 16px 18px;
  margin: 0 0 14px;
  border-radius: 4px;
}
.article .author {
  border-top: 1px solid var(--gray-line);
  margin-top: 36px;
  padding-top: 18px;
  font-size: 14px;
}

/* 留言讨论区 */
.comments {
  border-top: 1px solid var(--gray-line);
  margin-top: 44px;
  padding-top: 30px;
}
.comments h3 { margin: 0 0 8px; }
.giscus-box {
  border: 1px solid var(--gray-line);
  border-radius: 6px;
  background: var(--gray-bg);
  padding: 22px;
  margin-top: 16px;
}
.giscus-note { font-size: 13px; color: var(--gray-meta); margin: 0; }

/* 联系信息 */
.info-list { list-style: none; padding: 0; margin: 0; font-size: 14.5px; }
.info-list li { padding: 9px 0; border-bottom: 1px solid var(--gray-line); }
.info-list b { color: var(--navy); font-weight: 600; margin-right: 8px; }

/* 公众号关注卡片 */
.wx-card {
  display: flex;
  gap: 20px;
  align-items: center;
  background: var(--gray-bg);
  border: 1px solid var(--gray-line);
  border-left: 3px solid var(--teal);
  border-radius: 0 6px 6px 0;
  padding: 20px 22px;
  margin: 22px 0;
}
.wx-card .qr {
  flex: 0 0 108px;
  width: 108px;
  height: 108px;
  border: 1px solid var(--gray-line);
  border-radius: 4px;
  background: #fff;
  display: block;
  object-fit: contain;
}
.wx-card .wx-txt { flex: 1 1 auto; min-width: 0; }
.wx-card .wx-txt h4 { margin: 0 0 6px; font-size: 16.5px; color: var(--navy); }
.wx-card .wx-txt p { margin: 0 0 8px; font-size: 14px; }
.wx-card .wx-txt p:last-child { margin-bottom: 0; }
.wx-card .wx-name { font-size: 13.5px; color: var(--gray-meta); }
.wx-mini { display: flex; gap: 14px; align-items: flex-start; }
.wx-mini .qr {
  width: 84px; height: 84px; flex: 0 0 84px;
  border-radius: 4px;
  background: #fff;
  display: block;
  object-fit: contain;
}
.wx-mini .wx-txt h5 { margin: 0 0 4px; font-size: 14.5px; color: var(--navy); }
.wx-mini .wx-txt p { margin: 0; font-size: 13px; color: var(--gray-meta); }
/* 页脚为深色底，二维码旁文字需提亮以保持对比度与全站一致 */
footer .wx-mini .wx-txt p { color: #9FB2C6; }

/* 首页资质摘要条 */
.cert-strip {
  margin-top: 18px;
  padding-top: 15px;
  border-top: 1px solid var(--gray-line);
  font-size: 13.5px;
  color: #3E5A72;
  line-height: 1.9;
}
.cert-strip b { color: var(--navy); font-weight: 600; }
.cert-strip a { margin-left: 10px; white-space: nowrap; }

/* 资质证书墙：三列等高等宽，竖版证书按比例居中，点击放大看细节 */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 20px;
}
.cert {
  display: flex;
  flex-direction: column;
  margin: 0;
  border: 1px solid var(--gray-line);
  border-radius: 6px;
  background: #fff;
  overflow: hidden;
  transition: box-shadow .18s ease, transform .18s ease;
}
.cert:hover { box-shadow: 0 8px 24px rgba(14, 42, 71, .10); transform: translateY(-2px); }
.cert img {
  display: block;
  width: 100%;
  height: 268px;
  object-fit: contain;
  background: #FAFBFD;
  cursor: zoom-in;
  padding: 6px;
}
.cert figcaption {
  margin-top: auto;
  padding: 11px 13px 13px;
  border-top: 1px solid var(--gray-line);
}
.cert figcaption b { display: block; font-size: 14px; color: var(--navy); line-height: 1.5; }
.cert figcaption span { display: block; margin-top: 3px; font-size: 12.5px; color: var(--gray-meta); line-height: 1.55; }

/* 证书放大查看 */
.cert-viewer {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 999;
  background: rgba(8, 28, 49, .88);
  align-items: center;
  justify-content: center;
  padding: 40px 24px;
  cursor: zoom-out;
}
.cert-viewer.show { display: flex; }
.cert-viewer img {
  max-width: 100%;
  max-height: 100%;
  border-radius: 4px;
  background: #fff;
  box-shadow: 0 20px 60px rgba(0, 0, 0, .45);
}
.cert-viewer span {
  position: absolute;
  top: 18px;
  right: 26px;
  color: #DCE6F0;
  font-size: 13px;
}

@media (max-width: 860px) {
  .grid-2, .grid-3, .steps, .foot-grid { grid-template-columns: 1fr; }
  .cert-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .cert img { height: 170px; }
  .nav-toggle { display: block; }
  nav ul {
    display: none;
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: #fff; border-top: 1px solid #eee;
    box-shadow: 0 10px 24px rgba(20,40,80,.10);
    padding: 6px 0; z-index: 50;
  }
  .nav-cb:checked ~ nav ul { display: flex; }
  nav ul li { padding: 0; }
  nav ul li a { display: block; padding: 13px 20px; font-size: 15px; border-bottom: 1px solid #f3f3f3; }
  nav ul li.has-sub > ul.sub {
    display: block; position: static; box-shadow: none;
    padding: 0 0 6px 16px; background: #fafbfc;
  }
  nav ul li.has-sub > ul.sub li a { border-bottom: none; padding: 9px 0; font-size: 14px; color: #5b6b7d; }
  nav ul li.has-sub > ul.sub li a::before { content: '· '; }
  .hero h1 { font-size: 26px; }
  .hero { padding: 48px 0 40px; }
  .utilitybar .wrap { gap: 12px; font-size: 12px; justify-content: flex-start; overflow-x: auto; }
  .logo img { height: 26px; }
  .brand-block { flex-direction: column; align-items: flex-start; gap: 16px; }
  .quote-grid { grid-template-columns: 1fr; }
  .article h2 { font-size: 19px; }
  .wx-card { flex-direction: column; align-items: flex-start; }
  .wx-card .qr { width: 96px; height: 96px; flex-basis: 96px; }
}

/* ================= 品牌水印与内容保护 =================
   水印是一张透明底的 logo 平铺图（logo-watermark.png），由 logo-drh.png 反相取亮度生成。
   固定定位 + pointer-events:none：跟着视口移动、不响应鼠标，滚动时像印在纸面上。
   透明度刻意压得很低（约 8%—12%），截图仍能辨认品牌，但不会干扰阅读。
   关闭整套保护：地址后加 ?dev=1（见 assets/guard.js）。 */
body::before {
  content: "";
  position: fixed;
  inset: -30%;
  z-index: 1;
  background-image: url(logo-watermark.png);
  background-repeat: repeat;
  background-size: 400px 158px;
  opacity: .3;
  transform: rotate(-20deg);
  pointer-events: none;
}

/* 顶部信息条层级高于水印，避免水印压住电话邮箱。
   注意：header 本身是 sticky + z-index:100，这里不要碰它的 position，否则导航失去吸顶 */
.utilitybar { position: relative; z-index: 3; }

/* 默认不选中：降低「整段划走」的成本。输入框必须放行，否则客户贴不了下载密钥 */
body {
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
}
input, textarea, select, [contenteditable="true"] {
  -webkit-user-select: text;
  -moz-user-select: text;
  user-select: text;
  -webkit-touch-callout: default;
}
img { -webkit-user-drag: none; }

/* ?dev=1 时整站恢复可选可复制 */
html.guard-off body {
  -webkit-user-select: auto;
  -moz-user-select: auto;
  user-select: auto;
  -webkit-touch-callout: default;
}
html.guard-off body::before { display: none; }

/* 手机屏水印再压一档：屏小、图案占比大，太明显会干扰读参数 */
@media (max-width: 860px) {
  body::before { background-size: 300px 118px; opacity: .2; }
}

/* 打印：水印加深，页脚印一行版权，截图或纸质流出也能溯源 */
@media print {
  body::before { opacity: .85; }
  body::after {
    content: "© 福州热博汇新材料有限公司  fz-rbh.cn";
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 4px 12px;
    font-size: 10px;
    color: #6B7787;
    background: #fff;
  }
}