/* =========================================================
   工程安防垂直模板 · 设计系统与组件样式
   品牌：郑州监控安装有限公司（zzjkaz.com 真实底稿重建）
   配色：深蓝钢蓝 + 青色科技感 + 安全绿；SIL OFL 系统字体栈
   原则：原生语义化、响应式、不依赖外部字体 CDN
   ========================================================= */

:root {
  /* 色彩 */
  --c-ink: #0E1B2C;          /* 深墨蓝（标题/深色块） */
  --c-bg-dark: #0B1E36;      /* 深色区块（Hero/页脚） */
  --c-bg-dark-2: #102743;
  --c-primary: #0E4DA4;      /* 主蓝 */
  --c-primary-600: #1159B8;
  --c-primary-700: #0A3B7E;
  --c-accent: #12B5D6;       /* 青色（科技/监控感） */
  --c-accent-soft: #E3F7FB;
  --c-success: #1FA971;      /* 安全绿（质保/保障） */
  --c-success-soft: #E6F6EF;
  --c-bg: #FFFFFF;
  --c-bg-soft: #F3F6FB;
  --c-line: #E3E9F2;
  --c-text: #1C2B3A;
  --c-text-soft: #5C6B7B;
  --c-text-invert: #EAF1F9;

  /* 圆角 */
  --r-sm: 8px;
  --r: 14px;
  --r-lg: 22px;

  /* 阴影 */
  --sh-1: 0 2px 10px rgba(14, 27, 44, .06);
  --sh-2: 0 12px 34px rgba(14, 27, 44, .12);

  /* 布局 */
  --container: 1180px;
  --gap: 20px;

  /* 字体（SIL OFL 开源栈，不本地化 @font-face，不依赖 Google Fonts CDN） */
  --font: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei",
         "Hiragino Sans GB", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
  font-size: 16px;
}
img { max-width: 100%; display: block; }
a { color: var(--c-primary); text-decoration: none; }
a:hover { color: var(--c-primary-700); }

/* 容器 */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

/* 区块 */
.section { padding: 72px 0; }
.section--soft { background: var(--c-bg-soft); }
.section--dark { background: var(--c-bg-dark); color: var(--c-text-invert); }
.section__head { text-align: center; max-width: 760px; margin: 0 auto 44px; }
.section__eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--c-accent);
  font-weight: 700;
  margin-bottom: 10px;
}
.section__title {
  font-size: 30px;
  line-height: 1.3;
  margin: 0 0 12px;
  color: inherit;
  font-weight: 800;
}
.section--dark .section__title { color: #fff; }
.section__sub { color: var(--c-text-soft); margin: 0; font-size: 16px; }
.section--dark .section__sub { color: #B9C7DA; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: transform .12s ease, box-shadow .2s ease, background .2s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary { background: var(--c-primary); color: #fff; box-shadow: var(--sh-1); }
.btn--primary:hover { background: var(--c-primary-700); color: #fff; }
.btn--accent { background: var(--c-accent); color: #062430; }
.btn--accent:hover { background: #0FA0BE; color: #062430; }
.btn--ghost { background: transparent; border-color: var(--c-line); color: var(--c-text); }
.btn--ghost:hover { border-color: var(--c-primary); color: var(--c-primary); }
.btn--light { background: #fff; color: var(--c-primary-700); }
.btn--light:hover { background: #EAF1F9; }
.btn--block { width: 100%; justify-content: center; }

/* 顶部导航 */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.94);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--c-line);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--c-ink); font-size: 18px; }
.brand__mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  display: grid; place-items: center; color: #fff; font-size: 18px;
}
.brand small { display: block; font-size: 11px; font-weight: 600; color: var(--c-text-soft); letter-spacing: .04em; }
.nav__links { display: flex; align-items: center; gap: 26px; }
.nav__links a { color: var(--c-text); font-weight: 600; font-size: 15px; }
.nav__links a:hover, .nav__links a.is-active { color: var(--c-primary); }
.nav__cta { display: flex; align-items: center; gap: 12px; }
.nav__phone { font-weight: 800; color: var(--c-primary-700); font-size: 15px; }
.nav__toggle { display: none; background: none; border: 0; font-size: 24px; cursor: pointer; color: var(--c-ink); }

/* Hero */
.hero {
  position: relative;
  background:
    radial-gradient(1100px 500px at 80% -10%, rgba(18,181,214,.20), transparent 60%),
    linear-gradient(160deg, var(--c-bg-dark) 0%, var(--c-bg-dark-2) 100%);
  color: #fff;
  overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(700px 400px at 75% 20%, #000, transparent 75%);
  pointer-events: none;
}
.hero__grid {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center;
  padding: 84px 0 88px;
}
.hero__badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(18,181,214,.16); color: var(--c-accent);
  border: 1px solid rgba(18,181,214,.35);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 700; margin-bottom: 18px;
}
.hero h1 { font-size: 42px; line-height: 1.2; margin: 0 0 16px; font-weight: 900; letter-spacing: -.01em; }
.hero h1 .hl { color: var(--c-accent); }
.hero__lead { color: #C8D6E8; font-size: 17px; margin: 0 0 26px; max-width: 540px; }
.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 26px; }
.hero__trust { display: flex; gap: 26px; flex-wrap: wrap; }
.hero__trust div { display: flex; align-items: center; gap: 8px; color: #D6E2F1; font-size: 14px; font-weight: 600; }
.hero__trust .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--c-success); box-shadow: 0 0 0 4px rgba(31,169,113,.22); }
.hero__media { position: relative; }
.hero__media img { border-radius: var(--r-lg); box-shadow: var(--sh-2); border: 1px solid rgba(255,255,255,.12); }
.hero__media .tag {
  position: absolute; left: 16px; bottom: 16px;
  background: rgba(11,30,54,.8); color: #fff; padding: 8px 14px; border-radius: 10px;
  font-size: 13px; font-weight: 700; border: 1px solid rgba(255,255,255,.18);
}

/* 服务流程 steps */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); }
.step {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r);
  padding: 26px 24px; position: relative; box-shadow: var(--sh-1);
}
.step__no {
  width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center;
  background: var(--c-accent-soft); color: var(--c-primary-700); font-weight: 900; font-size: 18px; margin-bottom: 14px;
}
.step h3 { margin: 0 0 8px; font-size: 17px; }
.step p { margin: 0; color: var(--c-text-soft); font-size: 14.5px; }

/* 解决方案 / 卡片栅格 */
.grid { display: grid; gap: var(--gap); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r);
  padding: 26px 24px; box-shadow: var(--sh-1); transition: transform .15s ease, box-shadow .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--sh-2); border-color: #cfe0f2; }
.card__icon {
  width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent)); color: #fff; font-size: 22px; margin-bottom: 14px;
}
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0 0 14px; color: var(--c-text-soft); font-size: 14.5px; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tags span {
  font-size: 12.5px; color: var(--c-primary-700); background: var(--c-accent-soft);
  padding: 4px 10px; border-radius: 999px; font-weight: 600;
}

/* 价格 */
.price { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); align-items: stretch; }
.plan {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-lg);
  padding: 30px 26px; display: flex; flex-direction: column; box-shadow: var(--sh-1);
}
.plan--hot { border-color: var(--c-primary); box-shadow: 0 14px 40px rgba(14,77,164,.18); position: relative; }
.plan__flag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--c-primary); color: #fff; font-size: 12.5px; font-weight: 800;
  padding: 5px 16px; border-radius: 999px;
}
.plan__name { font-size: 19px; font-weight: 800; margin: 0 0 6px; }
.plan__price { font-size: 26px; font-weight: 900; color: var(--c-primary-700); margin: 0 0 4px; }
.plan__price small { font-size: 14px; color: var(--c-text-soft); font-weight: 600; }
.plan__desc { color: var(--c-text-soft); font-size: 14px; margin: 0 0 18px; }
.plan ul { list-style: none; padding: 0; margin: 0 0 22px; flex: 1; }
.plan li { padding: 9px 0 9px 26px; position: relative; border-top: 1px dashed var(--c-line); font-size: 14.5px; }
.plan li:first-child { border-top: 0; }
.plan li::before { content: "✓"; position: absolute; left: 0; top: 9px; color: var(--c-success); font-weight: 900; }

/* 案例 */
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); }
.case {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r);
  overflow: hidden; box-shadow: var(--sh-1); transition: transform .15s ease, box-shadow .2s ease;
}
.case:hover { transform: translateY(-3px); box-shadow: var(--sh-2); }
.case__media { aspect-ratio: 16/10; overflow: hidden; background: var(--c-bg-soft); }
.case__media img { width: 100%; height: 100%; object-fit: cover; }
.case__body { padding: 20px 22px 24px; }
.case__cat { font-size: 12.5px; color: var(--c-accent); font-weight: 800; letter-spacing: .04em; }
.case__body h3 { margin: 6px 0 10px; font-size: 17.5px; }
.case__body p { margin: 0 0 14px; color: var(--c-text-soft); font-size: 14.5px; }
.case__more { font-weight: 700; color: var(--c-primary); font-size: 14px; }

/* 场景条 */
.scenes { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.scene {
  border-radius: var(--r); overflow: hidden; position: relative; aspect-ratio: 4/3;
  border: 1px solid var(--c-line);
}
.scene img { width: 100%; height: 100%; object-fit: cover; }
.scene span {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 10px 12px;
  background: linear-gradient(transparent, rgba(11,30,54,.82)); color: #fff; font-size: 13.5px; font-weight: 700;
}

/* 关于 */
.about { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.about__media img { border-radius: var(--r-lg); box-shadow: var(--sh-2); }
.about ul { list-style: none; padding: 0; margin: 18px 0 0; }
.about li { display: flex; gap: 12px; padding: 12px 0; border-top: 1px solid var(--c-line); }
.about li:first-child { border-top: 0; }
.about li .ic { color: var(--c-success); font-weight: 900; font-size: 18px; }
.about li b { display: block; }
.about li span { color: var(--c-text-soft); font-size: 14.5px; }

/* FAQ */
.faq { max-width: 860px; margin: 0 auto; }
.faq details {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--r);
  padding: 4px 22px; margin-bottom: 12px; box-shadow: var(--sh-1);
}
.faq summary {
  cursor: pointer; list-style: none; padding: 16px 0; font-weight: 700; font-size: 16.5px;
  display: flex; justify-content: space-between; align-items: center; gap: 14px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 22px; color: var(--c-primary); font-weight: 900; }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 0 0 16px; color: var(--c-text-soft); }

/* 联系 */
.contact { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: start; }
.contact__info { background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-lg); padding: 30px; box-shadow: var(--sh-1); }
.contact__row { display: flex; gap: 12px; padding: 14px 0; border-top: 1px solid var(--c-line); }
.contact__row:first-child { border-top: 0; }
.contact__row .ic { color: var(--c-primary); font-size: 18px; }
.contact__row b { display: block; font-size: 15px; }
.contact__row a { font-weight: 800; color: var(--c-primary-700); font-size: 17px; }
.contact__qr { text-align: center; background: var(--c-bg-soft); border-radius: var(--r); padding: 20px; }
.contact__qr img { width: 170px; height: 170px; margin: 0 auto 10px; border-radius: 12px; background: #fff; padding: 8px; }
.contact__qr p { margin: 0; font-size: 14px; color: var(--c-text-soft); }
.contact__form { background: #fff; border: 1px solid var(--c-line); border-radius: var(--r-lg); padding: 30px; box-shadow: var(--sh-1); }
.contact__form label { display: block; font-weight: 700; font-size: 14px; margin: 0 0 6px; }
.contact__form input, .contact__form textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--c-line); border-radius: 10px;
  font-family: inherit; font-size: 15px; margin-bottom: 16px; background: #fff; color: var(--c-text);
}
.contact__form input:focus, .contact__form textarea:focus { outline: 2px solid var(--c-accent); border-color: transparent; }
.contact__note { font-size: 13px; color: var(--c-text-soft); margin-top: 4px; }

/* 知识库列表 */
.kb { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.kb__item {
  display: flex; gap: 14px; background: #fff; border: 1px solid var(--c-line); border-radius: var(--r);
  padding: 18px 20px; box-shadow: var(--sh-1); transition: border-color .2s ease, transform .15s ease;
}
.kb__item:hover { border-color: var(--c-primary); transform: translateY(-2px); }
.kb__no { color: var(--c-accent); font-weight: 900; font-size: 15px; min-width: 26px; }
.kb__item h3 { margin: 0 0 4px; font-size: 16px; }
.kb__item p { margin: 0; color: var(--c-text-soft); font-size: 13.5px; }
.kb__item .meta { font-size: 12px; color: #95a4b4; margin-top: 6px; }

/* 文章页 */
.article { max-width: 820px; margin: 0 auto; }
.article__head { text-align: center; max-width: 720px; margin: 0 auto 30px; }
.article__cat { color: var(--c-accent); font-weight: 800; font-size: 13px; letter-spacing: .06em; }
.article h1 { font-size: 30px; line-height: 1.35; margin: 8px 0 12px; }
.article__meta { color: var(--c-text-soft); font-size: 14px; }
.article__body { font-size: 17px; line-height: 1.9; }
.article__body h2 { font-size: 22px; margin: 34px 0 12px; }
.article__body p { margin: 0 0 18px; }
.article__body ul { padding-left: 22px; }
.article__body li { margin: 6px 0; }

/* 面包屑 */
.crumbs { font-size: 13.5px; color: var(--c-text-soft); padding: 18px 0 0; }
.crumbs a { color: var(--c-text-soft); }
.crumbs a:hover { color: var(--c-primary); }
.crumbs span { margin: 0 8px; }

/* CTA 条 */
.cta {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-700));
  border-radius: var(--r-lg); padding: 40px; text-align: center; color: #fff;
}
.cta h2 { margin: 0 0 10px; font-size: 26px; color: #fff; }
.cta p { margin: 0 0 22px; color: #D6E2F1; }

/* 页脚 */
.site-footer { background: var(--c-bg-dark); color: #C8D6E8; padding: 48px 0 28px; }
.footer__grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 30px; }
.site-footer h4 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.site-footer a { color: #C8D6E8; display: block; padding: 5px 0; font-size: 14px; }
.site-footer a:hover { color: #fff; }
.footer__brand { font-size: 19px; font-weight: 800; color: #fff; display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.footer__brand .brand__mark { width: 32px; height: 32px; }
.site-footer p { font-size: 14px; margin: 0 0 8px; }
.site-footer .tel { color: #fff; font-weight: 800; font-size: 17px; }
.footer__bottom { border-top: 1px solid rgba(255,255,255,.12); margin-top: 30px; padding-top: 18px; font-size: 13px; color: #93A4BA; text-align: center; }

/* 工具类 */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.lead { font-size: 17px; color: var(--c-text-soft); }
.muted { color: var(--c-text-soft); }

/* 响应式 */
@media (max-width: 980px) {
  .hero__grid { grid-template-columns: 1fr; gap: 30px; padding: 60px 0 64px; }
  .hero h1 { font-size: 34px; }
  .steps, .grid--3, .price, .cases { grid-template-columns: repeat(2, 1fr); }
  .scenes { grid-template-columns: repeat(2, 1fr); }
  .about, .contact { grid-template-columns: 1fr; }
  .kb { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 52px 0; }
  .section__title { font-size: 24px; }
  .nav__links, .nav__phone { display: none; }
  .nav__toggle { display: block; }
  .nav__links.is-open {
    display: flex; flex-direction: column; gap: 4px;
    position: absolute; top: 64px; left: 0; right: 0; background: #fff;
    border-bottom: 1px solid var(--c-line); padding: 12px 20px; box-shadow: var(--sh-2);
  }
  .nav__links.is-open a { padding: 10px 0; }
  .steps, .grid--3, .price, .cases, .scenes, .grid--2 { grid-template-columns: 1fr; }
  .hero h1 { font-size: 28px; }
  .cta { padding: 28px 20px; }
  .footer__grid { grid-template-columns: 1fr; }
}