/* ============================================================
   科新网络官网 — 样式表 (SEO Optimized)
   版本: 2.0 | 主色: 科技蓝 #2563eb | 高亮: 琥珀黄 #f59e0b
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --blue-light: #dbeafe;
  --blue-bg: #eff6ff;
  --amber: #f59e0b;
  --amber-light: #fef3c7;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --white: #ffffff;
  --red: #ef4444;
  --green: #10b981;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,.07),0 2px 4px -2px rgba(0,0,0,.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.08),0 4px 6px -4px rgba(0,0,0,.04);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,.1),0 8px 10px -6px rgba(0,0,0,.05);
  --radius: 12px;
  --radius-lg: 16px;
  --radius-sm: 8px;
  --transition: .25s cubic-bezier(.4,0,.2,1);
  --nav-height: 72px;
  --max-width: 1200px;
}

/* ---------- Reset ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:var(--nav-height)}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  font-size:16px;line-height:1.6;color:var(--gray-700);
  background:var(--white);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--blue);text-decoration:none;transition:color var(--transition)}
a:hover{color:var(--blue-dark)}
ul{list-style:none}

/* ---------- 通用布局 ---------- */
.shell{max-width:var(--max-width);margin:0 auto;padding:0 24px}

.section{padding:80px 0}
.section-head{text-align:center;margin-bottom:48px}
.eyebrow{
  display:inline-block;font-size:13px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;
  color:var(--blue);background:var(--blue-light);padding:4px 14px;border-radius:20px;margin-bottom:12px;
}
.section-head h2{font-size:32px;font-weight:800;color:var(--gray-900);margin-bottom:8px}
.section-head h2 .accent{color:var(--blue)}
.section-sub{font-size:16px;color:var(--gray-500);max-width:500px;margin:0 auto}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:15px;padding:12px 28px;
  border-radius:50px;border:2px solid transparent;cursor:pointer;transition:all var(--transition);
  text-decoration:none;white-space:nowrap;
}
.btn-primary{background:var(--blue);color:var(--white);border-color:var(--blue)}
.btn-primary:hover{background:var(--blue-dark);border-color:var(--blue-dark);color:var(--white);transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.btn-outline{background:transparent;color:var(--blue);border-color:var(--blue)}
.btn-outline:hover{background:var(--blue);color:var(--white)}
.btn-block{display:flex;width:100%;justify-content:center}

/* ==================== 导航栏 ==================== */
.site-header{
  position:sticky;top:0;z-index:1000;height:var(--nav-height);
  background:rgba(255,255,255,.85);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid rgba(0,0,0,.06);transition:all var(--transition);
}
.site-header.scrolled{box-shadow:var(--shadow-md)}

.nav{display:flex;align-items:center;justify-content:space-between;height:100%}

.brand{display:flex;align-items:center;gap:10px;color:var(--gray-900);font-weight:800;font-size:20px}
.brand:hover{color:var(--blue)}
.brand-icon{font-size:26px;color:var(--blue)}

.nav-actions{display:flex;align-items:center;gap:8px}
.nav-links{display:flex;align-items:center;gap:6px}
.nav-links a{
  padding:8px 16px;border-radius:8px;font-size:15px;font-weight:500;color:var(--gray-600);
  transition:all var(--transition);position:relative;
}
.nav-links a:hover{color:var(--blue);background:var(--blue-bg)}
.nav-links a.nav-cta{
  background:var(--blue);color:var(--white);padding:8px 20px;border-radius:50px;margin-left:8px;
}
.nav-links a.nav-cta:hover{background:var(--blue-dark);color:var(--white)}

/* 移动端菜单按钮 */
.menu-btn{
  display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:8px;z-index:1001;
}
.menu-btn span{
  display:block;width:24px;height:2.5px;background:var(--gray-700);border-radius:2px;
  transition:all var(--transition);
}

/* ==================== 英雄区 ==================== */
.hero{
  position:relative;padding:80px 0 100px;background:linear-gradient(135deg,#eff6ff 0%,#dbeafe 50%,#f0f9ff 100%);
  overflow:hidden;
}
.hero-bg{
  position:absolute;inset:0;
  background:radial-gradient(ellipse at 30% 50%,rgba(37,99,235,.08) 0%,transparent 70%),
             radial-gradient(ellipse at 70% 40%,rgba(245,158,11,.06) 0%,transparent 60%);
}
.hero-inner{position:relative;display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}

.hero-eyebrow{font-size:14px;font-weight:600;color:var(--blue);margin-bottom:16px;letter-spacing:.02em}
.hero-copy h1{font-size:44px;font-weight:900;color:var(--gray-900);line-height:1.2;margin-bottom:20px}
.hero-highlight{color:var(--blue)}
.hero-lead{font-size:18px;color:var(--gray-500);line-height:1.7;margin-bottom:32px;max-width:480px}
.hero-ctas{display:flex;gap:14px;flex-wrap:wrap}

.hero-stats{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.stat-item{
  background:var(--white);border-radius:var(--radius);padding:24px;text-align:center;
  box-shadow:var(--shadow-md);transition:transform var(--transition);
}
.stat-item:hover{transform:translateY(-4px)}
.stat-num{display:block;font-size:36px;font-weight:900;color:var(--amber)}
.stat-item span{font-size:14px;color:var(--gray-500);margin-top:4px;display:block}

/* ==================== 关于我们 ==================== */
.about-layout{display:grid;grid-template-columns:1.2fr .8fr;gap:48px;align-items:start}
.about-text p{font-size:16px;margin-bottom:16px;line-height:1.8}
.about-list{margin-top:20px}
.about-list li{display:flex;align-items:center;gap:10px;padding:8px 0;font-size:15px;color:var(--gray-600)}
.about-list li i{color:var(--green);font-size:18px;flex-shrink:0}
.about-service-areas{background:var(--blue-bg);border-radius:var(--radius-lg);padding:28px}
.about-service-areas h3{font-size:18px;font-weight:700;color:var(--gray-800);margin-bottom:16px}
.area-tags{display:flex;flex-wrap:wrap;gap:8px}
.area-tags span{
  background:var(--white);padding:8px 16px;border-radius:20px;font-size:14px;font-weight:500;
  color:var(--blue);box-shadow:var(--shadow-sm);transition:all var(--transition);
}
.area-tags span:hover{background:var(--blue);color:var(--white);transform:translateY(-1px)}

/* ==================== 服务卡片 ==================== */
.services{background:var(--gray-50)}
.service-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}

.svc-card{
  background:var(--white);border-radius:var(--radius-lg);padding:32px 24px;text-align:center;
  box-shadow:var(--shadow-md);transition:all var(--transition);
  border:2px solid transparent;position:relative;overflow:hidden;
}
.svc-card:hover{transform:translateY(-8px);box-shadow:var(--shadow-xl);border-color:var(--blue)}
.svc-card-featured{border-color:var(--blue);background:linear-gradient(180deg,#eff6ff 0%,var(--white) 30%)}
.svc-badge{
  position:absolute;top:16px;right:16px;background:var(--amber);color:var(--white);font-size:12px;
  font-weight:700;padding:4px 12px;border-radius:20px;
}
.svc-icon{
  width:64px;height:64px;margin:0 auto 20px;background:var(--blue-bg);border-radius:50%;
  display:flex;align-items:center;justify-content:center;font-size:26px;color:var(--blue);
}
.svc-card h3{font-size:18px;font-weight:700;color:var(--gray-800);margin-bottom:8px}
.svc-card>p{font-size:14px;color:var(--gray-500);margin-bottom:16px;min-height:40px}
.svc-price{margin:8px 0}
.price-label{font-size:13px;color:var(--gray-400);display:block}
.price-num{font-size:28px;font-weight:900;color:var(--amber)}
.price-suffix{font-size:14px;color:var(--gray-400)}
.svc-features{margin-top:16px;text-align:left}
.svc-features li{display:flex;align-items:center;gap:8px;padding:6px 0;font-size:13px;color:var(--gray-600)}
.svc-features li i{color:var(--green);font-size:12px;flex-shrink:0}

/* ==================== 案例展示 ==================== */
.case-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.case-card{background:var(--white);border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow-md);transition:all var(--transition)}
.case-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-xl)}
.case-img-wrap{position:relative;height:160px;background:var(--gray-100);display:flex;align-items:center;justify-content:center}
.case-placeholder{font-size:48px;color:var(--blue);opacity:.5}
.case-tag{
  position:absolute;top:12px;left:12px;background:var(--blue);color:var(--white);
  font-size:12px;font-weight:600;padding:4px 12px;border-radius:20px;
}
.case-body{padding:20px}
.case-body h4{font-size:16px;font-weight:700;color:var(--gray-800);margin-bottom:8px}
.case-body p{font-size:14px;color:var(--gray-500);line-height:1.6;margin-bottom:12px}
.case-location{font-size:13px;color:var(--blue);font-weight:500}
.case-location i{margin-right:4px}

/* ==================== 行业资讯 ==================== */
.news{background:var(--gray-50)}
.news-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.news-card{
  background:var(--white);border-radius:var(--radius-lg);padding:24px;
  box-shadow:var(--shadow-md);transition:all var(--transition);
}
.news-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.news-cat{
  display:inline-block;font-size:12px;font-weight:600;padding:3px 10px;border-radius:12px;
  background:var(--blue-light);color:var(--blue);margin-bottom:8px;
}
.news-card time{display:block;font-size:13px;color:var(--gray-400);margin-bottom:8px}
.news-card h4{font-size:16px;font-weight:700;line-height:1.4;margin-bottom:8px}
.news-card h4 a{color:var(--gray-800)}
.news-card h4 a:hover{color:var(--blue)}
.news-card p{font-size:14px;color:var(--gray-500);line-height:1.6}

/* ==================== FAQ ==================== */
.faq{background:var(--white)}
.faq-list{max-width:720px;margin:0 auto}
.faq-item{border:1px solid var(--gray-200);border-radius:var(--radius);margin-bottom:12px;overflow:hidden;transition:all var(--transition)}
.faq-item:hover{border-color:var(--blue-light)}
.faq-item.active{border-color:var(--blue);box-shadow:var(--shadow-md)}
.faq-question{
  width:100%;display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:18px 24px;background:var(--white);border:none;cursor:pointer;
  font-size:16px;font-weight:600;color:var(--gray-800);text-align:left;
  transition:all var(--transition);
}
.faq-question:hover{background:var(--blue-bg)}
.faq-question i{font-size:14px;color:var(--gray-400);transition:transform var(--transition);flex-shrink:0}
.faq-item.active .faq-question i{transform:rotate(180deg);color:var(--blue)}
.faq-answer{max-height:0;overflow:hidden;transition:max-height .35s ease}
.faq-item.active .faq-answer{max-height:300px}
.faq-answer p{padding:0 24px 20px;font-size:15px;color:var(--gray-600);line-height:1.7}

/* ==================== 联系我们 ==================== */
.contact{background:var(--gray-50)}
.contact-layout{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:start}
.contact-form{background:var(--white);border-radius:var(--radius-lg);padding:32px;box-shadow:var(--shadow-md)}
.form-group{margin-bottom:20px}
.form-group label{display:block;font-size:14px;font-weight:600;color:var(--gray-700);margin-bottom:6px}
.required{color:var(--red)}
.form-group input,
.form-group select,
.form-group textarea{
  width:100%;padding:12px 16px;border:1.5px solid var(--gray-300);border-radius:var(--radius-sm);
  font-size:15px;color:var(--gray-700);background:var(--white);transition:border-color var(--transition);
  font-family:inherit;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus{
  outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.1)
}
.form-group input.error,
.form-group textarea.error{border-color:var(--red)}
.form-group input.valid{border-color:var(--green)}
.form-note{font-size:12px;color:var(--gray-400);text-align:center;margin-top:16px}
.form-note a{color:var(--gray-500);text-decoration:underline}

.contact-info{display:flex;flex-direction:column;gap:16px}
.info-card{
  display:flex;align-items:flex-start;gap:16px;background:var(--white);border-radius:var(--radius);
  padding:20px;box-shadow:var(--shadow-sm);transition:all var(--transition);
}
.info-card:hover{box-shadow:var(--shadow-md)}
.info-icon{
  width:44px;height:44px;min-width:44px;background:var(--blue-bg);border-radius:50%;
  display:flex;align-items:center;justify-content:center;font-size:18px;color:var(--blue);
}
.info-card strong{display:block;font-size:15px;color:var(--gray-800);margin-bottom:4px}
.info-card p{font-size:14px;color:var(--gray-500)}
.info-card a{color:var(--blue);font-weight:500}

/* ==================== 底部 ==================== */
.site-footer{background:var(--gray-900);color:var(--gray-300);padding-top:56px}
.footer-inner{display:grid;grid-template-columns:1fr 2fr;gap:48px;padding-bottom:40px}
.footer-brand .brand-icon{font-size:28px;color:var(--blue);display:block;margin-bottom:8px}
.footer-brand strong{display:block;font-size:20px;color:var(--white);margin-bottom:4px}
.footer-brand p{font-size:14px;color:var(--gray-400)}
.footer-links{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.footer-col h4{font-size:16px;font-weight:700;color:var(--white);margin-bottom:16px}
.footer-col ul li{padding:6px 0}
.footer-col ul li a{font-size:14px;color:var(--gray-400);transition:color var(--transition)}
.footer-col ul li a:hover{color:var(--white)}
.footer-col ul li{font-size:14px;color:var(--gray-400)}
.footer-col i{margin-right:6px;color:var(--blue)}
.footer-bottom{border-top:1px solid var(--gray-800);padding:20px 0;text-align:center}
.footer-bottom p{font-size:13px;color:var(--gray-500);margin:4px 0}
.footer-bottom a{color:var(--gray-400)}
.footer-bottom a:hover{color:var(--white)}

/* ==================== 移动端底部导航 ==================== */
.mobile-bottom-nav{
  display:none;position:fixed;bottom:0;left:0;right:0;z-index:999;
  background:rgba(255,255,255,.95);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  border-top:1px solid var(--gray-200);padding:6px 0 env(safe-area-inset-bottom,8px);
  justify-content:space-around;
}
.mobile-bottom-nav a{
  display:flex;flex-direction:column;align-items:center;gap:2px;padding:4px 16px;
  font-size:11px;color:var(--gray-500);text-decoration:none;transition:color var(--transition);
}
.mobile-bottom-nav a i{font-size:20px}
.mobile-bottom-nav a:hover,.mobile-bottom-nav a:active{color:var(--blue)}

/* ==================== 侧滑菜单 ==================== */
.side-drawer-overlay{
  position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:1100;opacity:0;pointer-events:none;
  transition:opacity var(--transition);
}
.side-drawer-overlay.active{opacity:1;pointer-events:auto}
.side-drawer{
  position:fixed;top:0;right:0;bottom:0;width:280px;z-index:1101;
  background:var(--white);padding:24px;transform:translateX(100%);
  transition:transform .3s cubic-bezier(.4,0,.2,1);
  overflow-y:auto;
}
.side-drawer.active{transform:translateX(0)}
.drawer-close{
  display:block;margin-left:auto;background:none;border:none;font-size:32px;color:var(--gray-500);
  cursor:pointer;padding:0 8px;line-height:1;
}
.drawer-close:hover{color:var(--gray-800)}
.side-drawer nav{margin-top:24px}
.side-drawer nav a{
  display:block;padding:14px 16px;font-size:16px;font-weight:500;color:var(--gray-700);
  border-radius:var(--radius-sm);transition:all var(--transition);
}
.side-drawer nav a:hover{background:var(--blue-bg);color:var(--blue)}
.side-drawer .drawer-cta{
  background:var(--blue)!important;color:var(--white)!important;text-align:center;
  margin-top:12px;border-radius:50px!important;
}

/* ==================== 回到顶部 ==================== */
.back-to-top{
  position:fixed;bottom:80px;right:24px;z-index:998;
  width:44px;height:44px;border-radius:50%;background:var(--blue);color:var(--white);
  border:none;cursor:pointer;font-size:18px;display:flex;align-items:center;justify-content:center;
  box-shadow:var(--shadow-lg);opacity:0;pointer-events:none;transform:translateY(10px);
  transition:all var(--transition);
}
.back-to-top.visible{opacity:1;pointer-events:auto;transform:translateY(0)}
.back-to-top:hover{background:var(--blue-dark);transform:translateY(-3px)}

/* ==================== 响应式设计 ==================== */

/* 平板 (≤1024px) */
@media (max-width:1024px){
  .hero-inner{grid-template-columns:1fr;gap:40px}
  .hero-stats{grid-template-columns:repeat(4,1fr);gap:12px}
  .service-cards{grid-template-columns:repeat(2,1fr)}
  .case-grid{grid-template-columns:repeat(2,1fr)}
  .news-grid{grid-template-columns:repeat(2,1fr)}
  .contact-layout{grid-template-columns:1fr}
  .footer-inner{grid-template-columns:1fr;gap:32px}
  .footer-links{grid-template-columns:repeat(3,1fr)}
}

/* 手机 (≤768px) */
@media (max-width:768px){
  .section{padding:56px 0}
  .shell{padding:0 16px}

  /* 导航 */
  .nav-links{display:none}
  .menu-btn{display:flex}
  .site-header{height:60px}
  :root{--nav-height:60px}

  /* 英雄 */
  .hero{padding:56px 0 64px}
  .hero-copy h1{font-size:28px}
  .hero-lead{font-size:15px}
  .hero-stats{grid-template-columns:repeat(2,1fr)}
  .stat-num{font-size:28px}
  .hero-ctas{flex-direction:column}
  .hero-ctas .btn{justify-content:center}

  /* 关于 */
  .about-layout{grid-template-columns:1fr;gap:32px}

  /* 服务 */
  .service-cards{grid-template-columns:1fr;gap:16px}

  /* 案例 */
  .case-grid{grid-template-columns:1fr;gap:16px}

  /* 资讯 */
  .news-grid{grid-template-columns:1fr;gap:16px}

  /* FAQ */
  .faq-question{font-size:15px;padding:14px 18px}
  .faq-answer p{padding:0 18px 16px}

  /* 联系 */
  .contact-layout{gap:24px}
  .contact-form{padding:24px}

  /* 底部 */
  .footer-links{grid-template-columns:1fr;gap:20px}

  /* 移动端底部导航显示 */
  .mobile-bottom-nav{display:flex}
  .back-to-top{bottom:80px;right:12px}
  body{padding-bottom:70px}
}

/* 小手机 (≤480px) */
@media (max-width:480px){
  .section-head h2{font-size:24px}
  .hero-copy h1{font-size:24px}
  .hero-stats{gap:8px}
  .stat-item{padding:16px 8px}
  .stat-num{font-size:24px}
  .stat-item span{font-size:12px}
  .svc-card{padding:24px 16px}
}

/* ---------- 打印样式 ---------- */
@media print{
  .site-header,.mobile-bottom-nav,.side-drawer,.back-to-top,.hero-bg{display:none!important}
  .section{padding:20px 0;page-break-inside:avoid}
  body{font-size:12pt;color:#000}
  a{color:#000;text-decoration:underline}
}

/* ---------- 减少动画 ---------- */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  html{scroll-behavior:auto}
}