/* ============================================================
   石家庄知理工程技术有限公司 · 企业官网
   设计系统 —— 苹果风格 · 简约大气 · 零构建静态站点
   颜色 / 字体 / 间距 均通过 CSS 变量集中管理，便于统一换肤
   ============================================================ */
:root{
  --bg:#ffffff;
  --alt:#f5f5f7;          /* 苹果经典浅灰底 */
  --fg:#1d1d1f;           /* 主文字 */
  --muted:#6e6e73;        /* 次级文字 */
  --line:#d2d2d7;         /* 分割线 */
  --accent:#0071e3;       /* 苹果蓝 */
  --accent-hover:#0077ed;
  --radius:18px;
  --maxw:1280px;          /* 内容最大宽度（随大屏动态扩展） */
  --nav-h:56px;
  --shadow:0 12px 40px rgba(0,0,0,.10);
  --font:"Inter","Noto Sans SC","Microsoft YaHei","PingFang SC","Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}

/* 本地字体：英文 Inter + 中文 思源黑体(Noto Sans SC)，已随站打包，无需外部 CDN */
@font-face{font-family:"Inter";font-style:normal;font-weight:400;font-display:swap;src:url("../assets/fonts/inter-latin-400-normal.woff2") format("woff2");}
@font-face{font-family:"Inter";font-style:normal;font-weight:500;font-display:swap;src:url("../assets/fonts/inter-latin-500-normal.woff2") format("woff2");}
@font-face{font-family:"Inter";font-style:normal;font-weight:700;font-display:swap;src:url("../assets/fonts/inter-latin-700-normal.woff2") format("woff2");}
@font-face{font-family:"Noto Sans SC";font-style:normal;font-weight:400;font-display:swap;src:url("../assets/fonts/noto-sans-sc-chinese-simplified-400-normal.woff2") format("woff2");}
@font-face{font-family:"Noto Sans SC";font-style:normal;font-weight:500;font-display:swap;src:url("../assets/fonts/noto-sans-sc-chinese-simplified-500-normal.woff2") format("woff2");}
@font-face{font-family:"Noto Sans SC";font-style:normal;font-weight:700;font-display:swap;src:url("../assets/fonts/noto-sans-sc-chinese-simplified-700-normal.woff2") format("woff2");}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;color:var(--fg);background:var(--bg);
  line-height:1.6;font-family:var(--font);
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
}
a{color:inherit;text-decoration:none;}
img{max-width:80%;display:block;}
h1,h2,h3{letter-spacing:-.02em;}

/* ===================== 导航 NAV ===================== */
.nav{
  position:sticky;top:0;z-index:100;
  background:rgba(74,76,84,.92);
  backdrop-filter:saturate(180%) blur(20px);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;height:var(--nav-h);
  display:flex;align-items:center;gap:28px;padding:0 22px;
}
.brand{font-size:27px;font-weight:400;white-space:nowrap;letter-spacing:.2px;color:#fff;}
.nav-links{display:flex;gap:30px;font-size:21px;color:rgba(255,255,255,.82);}
.nav-links a{transition:color .2s;position:relative;color:rgba(255,255,255,.82);}
.nav-links a:hover{color:#fff;}
.nav-links a.active{color:#fff;}
.nav-right{margin-left:auto;display:flex;align-items:center;gap:14px;}
.lang-toggle{
  border:1px solid rgba(255,255,255,.4);background:transparent;border-radius:980px;
  padding:6px 16px;font-size:18px;cursor:pointer;color:#fff;
  transition:border-color .2s,color .2s;
}
.lang-toggle:hover{border-color:#fff;color:#fff;}
.menu-toggle{
  display:none;border:none;background:none;font-size:33px;
  cursor:pointer;color:#fff;line-height:1;
}

/* ===================== 英雄区 HERO ===================== */
.hero{
  text-align:center;padding:96px 22px 72px;
  background:linear-gradient(180deg,#fbfbfd 0%,#ffffff 100%);
}
.hero-eyebrow{color:var(--accent);font-weight:600;font-size:30px;margin:0 0 10px;letter-spacing:.02em;}
.hero-title{font-size:clamp(38px,6.2vw,72px);font-weight:700;line-height:1.05;margin:0 0 18px;}
.hero-sub{font-size:clamp(17px,2.4vw,22px);color:var(--muted);max-width:680px;margin:0 auto 30px;}
.hero-actions{display:flex;gap:20px;justify-content:center;flex-wrap:wrap;align-items:center;}
.hero-figure{margin:48px auto 0;max-width:1200px;}
.hero-figure img{border-radius:var(--radius);box-shadow:var(--shadow);width:100%;}

/* ===================== 按钮 ===================== */
.btn{
  padding:11px 24px;border-radius:980px;font-size:20px;font-weight:500;
  cursor:pointer;transition:background .2s,color .2s,opacity .2s;display:inline-block;border:1px solid transparent;
}
.btn-primary{background:var(--accent);color:#fff;}
.btn-primary:hover{background:var(--accent-hover);}
.btn-ghost{background:transparent;border-color:var(--accent);color:var(--accent);}
.btn-ghost:hover{background:rgba(0,113,227,.06);}
.btn-text{color:var(--accent);font-size:20px;}
.btn-text::after{content:" ›";}
.btn-text:hover{text-decoration:underline;}

/* ===================== 通用区块 ===================== */
.section{max-width:var(--maxw);margin:0 auto;padding:84px 22px;}
.section-alt{background:var(--alt);}
.section-alt > *{max-width:var(--maxw);margin-left:auto;margin-right:auto;}
.section-head{text-align:center;margin-bottom:46px;}
.section-title{font-size:clamp(30px,4.4vw,46px);font-weight:700;margin:0 0 12px;}
.section-desc{color:var(--muted);font-size:clamp(16px,2vw,19px);max-width:640px;margin:0 auto;}

/* ===================== 首页：业务领域卡片 ===================== */
.biz-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px;}
.biz-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:30px 26px;transition:transform .25s,box-shadow .25s;
}
.biz-card:hover{transform:translateY(-4px);box-shadow:var(--shadow);}
.biz-ico{font-size:30px;margin-bottom:14px;}
.biz-card h3{font-size:20px;margin:0 0 8px;}
.biz-card p{color:var(--muted);font-size:14.5px;margin:0;}

/* ===================== 首页：公司简介两段 ===================== */
.split{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center;}
.split-media img{border-radius:var(--radius);box-shadow:var(--shadow);width:100%;}
.split-text h2{font-size:clamp(26px,3.6vw,38px);font-weight:700;margin:0 0 16px;}
.split-text p{color:var(--muted);font-size:16.5px;margin:0 0 16px;}
.stat-row{display:flex;gap:36px;flex-wrap:wrap;margin-top:8px;}
.stat .num{font-size:34px;font-weight:700;color:var(--fg);}
.stat .lbl{font-size:13px;color:var(--muted);}

/* ===================== 产品网格 ===================== */
.product-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));gap:22px;}
.product-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;cursor:pointer;transition:transform .25s,box-shadow .25s;
  display:flex;flex-direction:column;
}
.product-card:hover{transform:translateY(-4px);box-shadow:var(--shadow);}
.pc-media{aspect-ratio:4/3;background:var(--alt);}
.pc-media img{width:100%;height:100%;object-fit:cover;}
.pc-body{padding:22px;display:flex;flex-direction:column;gap:6px;}
.pc-cat{font-size:12px;color:var(--accent);margin:0;font-weight:600;text-transform:uppercase;letter-spacing:.5px;}
.pc-name{font-size:20px;font-weight:600;margin:0;}
.pc-tag{font-size:14px;color:var(--muted);margin:0 0 6px;}
.pc-link{font-size:14px;color:var(--accent);font-weight:500;margin-top:auto;}

/* 分类筛选 */
.filter-bar{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:34px;}
.filter-chip{
  border:1px solid var(--line);background:#fff;border-radius:980px;
  padding:7px 18px;font-size:14px;cursor:pointer;color:var(--muted);transition:.2s;
}
.filter-chip:hover{color:var(--fg);border-color:var(--fg);}
.filter-chip.active{background:var(--fg);color:#fff;border-color:var(--fg);}

/* ===================== 资料下载列表 ===================== */
.dl-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;}
.dl-item{
  display:flex;align-items:center;gap:14px;padding:16px 18px;
  background:#fff;border:1px solid var(--line);border-radius:14px;
  transition:border-color .2s,transform .2s;
}
.dl-item:hover{border-color:var(--accent);transform:translateY(-2px);}
.dl-ico{color:var(--accent);font-size:20px;}
.dl-prod{font-size:12px;color:var(--muted);}
.dl-label{font-size:15px;font-weight:500;margin-left:auto;}

/* ===================== 关于我们 ===================== */
.about-hero{padding:80px 22px 40px;text-align:center;max-width:860px;margin:0 auto;}
.about-hero h1{font-size:clamp(34px,5vw,56px);font-weight:700;margin:0 0 16px;}
.about-hero p{color:var(--muted);font-size:18px;}
.timeline{display:flex;flex-direction:column;gap:0;margin-top:20px;}
.tl-item{display:grid;grid-template-columns:120px 1fr;gap:24px;padding:22px 0;border-top:1px solid var(--line);}
.tl-year{font-weight:700;color:var(--accent);font-size:18px;}
.tl-body h3{margin:0 0 6px;font-size:18px;}
.tl-body p{margin:0;color:var(--muted);font-size:15px;}
.value-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px;}
.value-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px 24px;}
.value-card h3{font-size:19px;margin:0 0 8px;}
.value-card p{color:var(--muted);font-size:14.5px;margin:0;}

/* ===================== 联系我们 ===================== */
.contact-wrap{display:grid;grid-template-columns:1.15fr .85fr;gap:44px;align-items:start;}
.contact-form{display:flex;flex-direction:column;gap:16px;}
.contact-form label{display:flex;flex-direction:column;gap:6px;font-size:14px;color:var(--muted);}
.contact-form input,.contact-form textarea{
  padding:12px 14px;border:1px solid var(--line);border-radius:12px;
  font-size:15px;font-family:inherit;outline:none;transition:border-color .2s;background:#fff;
}
.contact-form input:focus,.contact-form textarea:focus{border-color:var(--accent);}
.contact-form .btn{align-self:flex-start;}
.form-status{font-size:14px;margin:4px 0 0;}
.form-status.ok{color:#1a8a3a;}
.form-status.err{color:#c0392b;}
.contact-info{
  background:#eaf2fb;border:1px solid #d4e6f7;border-radius:var(--radius);
  padding:28px 26px;
}
.contact-info h3{margin:0 0 16px;font-size:19px;}
.contact-info .ci-row{display:flex;gap:12px;margin:0 0 16px;font-size:15px;}
.contact-info .ci-row .ci-ico{color:var(--accent);font-size:18px;min-width:22px;}
.contact-info .ci-row .ci-label{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.4px;display:block;}
.contact-info a{color:var(--accent);}
.contact-info .ci-map{margin-top:18px;border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);}

/* ===================== 页脚 FOOTER ===================== */
.footer{border-top:1px solid var(--line);background:var(--alt);margin-top:60px;}
.footer-inner{max-width:var(--maxw);margin:0 auto;padding:40px 22px;display:flex;flex-direction:column;gap:16px;align-items:center;text-align:center;}
.footer-brand{font-weight:600;font-size:16px;}
.footer-nav{display:flex;gap:24px;font-size:18.2px;color:var(--muted);flex-wrap:wrap;justify-content:center;}
.footer-nav a:hover{color:var(--fg);}
.footer-copy{font-size:15.6px;color:var(--muted);margin:0;}

/* ===================== 模态框 MODAL ===================== */
.modal{position:fixed;inset:0;z-index:200;display:flex;align-items:center;justify-content:center;padding:20px;}
.modal.hidden{display:none;}
.modal-backdrop{position:absolute;inset:0;background:rgba(0,0,0,.45);backdrop-filter:blur(4px);}
.modal-panel{
  position:relative;background:#fff;border-radius:20px;max-width:960px;width:100%;
  max-height:90vh;overflow:auto;box-shadow:0 30px 80px rgba(0,0,0,.3);
}
.modal-close{
  position:absolute;top:14px;right:16px;z-index:2;width:36px;height:36px;
  border:none;border-radius:50%;background:rgba(0,0,0,.06);font-size:22px;line-height:1;
  cursor:pointer;color:var(--fg);
}
.modal-close:hover{background:rgba(0,0,0,.12);}
.modal-body{display:grid;grid-template-columns:1.1fr 1fr;}
.m-gallery{background:var(--alt);padding:22px;display:flex;flex-direction:column;gap:12px;}
.m-gallery img{width:100%;border-radius:12px;object-fit:cover;}
.m-info{padding:36px;}
.m-cat{color:var(--accent);font-size:13px;font-weight:600;text-transform:uppercase;letter-spacing:.5px;margin:0 0 8px;}
.m-name{font-size:30px;font-weight:700;margin:0 0 8px;}
.m-tag{color:var(--accent);margin:0 0 16px;font-size:16px;}
.m-desc{color:var(--muted);margin:0 0 22px;}
.m-sub{font-size:15px;margin:18px 0 10px;font-weight:600;}
.m-spec{width:100%;border-collapse:collapse;}
.m-spec th,.m-spec td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line);font-size:14px;vertical-align:top;}
.m-spec th{color:var(--muted);font-weight:500;width:42%;}
.m-dls{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px;}
.dl-btn{padding:10px 16px;background:var(--alt);border-radius:980px;font-size:14px;font-weight:500;border:1px solid var(--line);transition:.2s;}
.dl-btn:hover{border-color:var(--accent);color:var(--accent);}
.muted{color:var(--muted);}

/* ===================== 滚动渐显 ===================== */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .8s ease,transform .8s ease;}
.reveal.in{opacity:1;transform:none;}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none;}
  html{scroll-behavior:auto;}
}

/* ===================== 响应式 ===================== */
@media (max-width:860px){
  .nav-links{
    position:absolute;top:var(--nav-h);left:0;right:0;background:#222;
    border-bottom:1px solid rgba(255,255,255,.12);flex-direction:column;gap:0;padding:6px 0;display:none;
  }
  .nav.open .nav-links{display:flex;}
  .nav-links a{padding:13px 22px;}
  .menu-toggle{display:block;}
  .split{grid-template-columns:1fr;gap:28px;}
  .contact-wrap{grid-template-columns:1fr;}
  .modal-body{grid-template-columns:1fr;}
  .tl-item{grid-template-columns:80px 1fr;gap:14px;}
}