/* =========================================================
   知否科技 · 企业官网
   设计风格：简约大气 | 现代克制 | 大量留白
   ========================================================= */

:root {
  /* 品牌色 */
  --brand: #4f46e5;
  --brand-600: #4338ca;
  --brand-700: #3730a3;
  --brand-cyan: #06b6d4;

  /* 中性色 */
  --ink: #0f172a;
  --text: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --bg-dark: #0f172a;

  /* 渐变 */
  --grad: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
  --grad-soft: linear-gradient(135deg, rgba(79,70,229,0.08) 0%, rgba(6,182,212,0.08) 100%);

  /* 排版 */
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 10px 40px -12px rgba(15, 23, 42, 0.12);
  --shadow-sm: 0 4px 20px -8px rgba(15, 23, 42, 0.10);
  --maxw: 1200px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 文字工具 ---------- */
.section { padding: 100px 0; }
.section-soft { background: var(--bg-soft); }
.center { text-align: center; }


.h-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  color: var(--ink);
  line-height: 1.25;
  letter-spacing: -0.5px;
}

.h-sub {
  font-size: 17px;
  color: var(--muted);
  max-width: 640px;
  margin: 18px auto 0;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  border: none;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
  white-space: nowrap;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 12px 30px -10px rgba(79,70,229,.55); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 40px -12px rgba(79,70,229,.6); }
.btn-ghost { background: transparent; color: var(--ink); border: 1.5px solid var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-light { background: #fff; color: var(--brand); }
.btn-light:hover { transform: translateY(-2px); box-shadow: var(--shadow); }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  color: var(--ink);
  letter-spacing: .5px;
}
.brand .logo-mark {
  width: 38px; height: 38px;
  border-radius: 11px;
  background: var(--grad);
  display: grid; place-items: center;
  color: #fff; font-size: 18px; font-weight: 800;
}
.nav-links { display: flex; align-items: center; gap: 34px; }
.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  position: relative;
  transition: color .2s;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -6px;
  width: 0; height: 2px;
  background: var(--grad);
  transition: width .25s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--brand); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-cta { display: flex; align-items: center; gap: 14px; }

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.menu-toggle span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; transition: .3s; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 130px 0 120px;
  background:
    radial-gradient(900px 500px at 80% -10%, rgba(6,182,212,.12), transparent 60%),
    radial-gradient(800px 500px at 0% 10%, rgba(79,70,229,.12), transparent 55%),
    var(--bg);
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: .35;
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000, transparent 75%);
  mask-image: radial-gradient(circle at 50% 30%, #000, transparent 75%);
}
.hero-inner { position: relative; max-width: 820px; }
.hero h1 {
  font-size: clamp(38px, 6vw, 64px);
  font-weight: 800;
  color: var(--ink);
  line-height: 1.15;
  letter-spacing: -1px;
}
.hero h1 .accent {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero p.lead {
  font-size: 19px;
  color: var(--muted);
  margin: 26px 0 38px;
  max-width: 640px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--line);
  font-size: 14px;
  color: var(--text);
  margin-bottom: 26px;
  box-shadow: var(--shadow-sm);
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: #22c55e; box-shadow: 0 0 0 4px rgba(34,197,94,.18); }

/* ---------- 数据条 ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  background: var(--bg-dark);
  border-radius: 24px;
  padding: 46px 40px;
  margin-top: -60px;
  position: relative;
  z-index: 5;
  box-shadow: var(--shadow);
}
.stat { text-align: center; }
.stat .num {
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.stat .label { color: #cbd5e1; font-size: 15px; margin-top: 6px; }

/* ---------- 区块标题 ---------- */
.block-head { text-align: center; margin-bottom: 60px; }

/* ---------- 业务卡片 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 38px 32px;
  transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.card .icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  background: var(--grad-soft);
  display: grid; place-items: center;
  margin-bottom: 22px;
  color: var(--brand);
}
.card h3 { font-size: 21px; font-weight: 700; color: var(--ink); margin-bottom: 12px; }
.card p { color: var(--muted); font-size: 15px; }
.card .more { display: inline-block; margin-top: 18px; color: var(--brand); font-weight: 600; font-size: 15px; }

/* ---------- 优势 ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.adv {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform .3s, box-shadow .3s;
}
.adv:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.adv .n { font-size: 14px; font-weight: 700; color: var(--brand); letter-spacing: 1px; }
.adv h4 { font-size: 18px; margin: 12px 0 8px; color: var(--ink); }
.adv p { font-size: 14px; color: var(--muted); }

/* ---------- 时间线 ---------- */
.timeline { position: relative; max-width: 820px; margin: 0 auto; }
.timeline::before {
  content: "";
  position: absolute;
  left: 22px; top: 8px; bottom: 8px;
  width: 2px;
  background: linear-gradient(var(--brand), var(--brand-cyan));
}
.tl-item { position: relative; padding: 0 0 44px 70px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-dot {
  position: absolute; left: 13px; top: 4px;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: #fff;
  border: 4px solid var(--brand);
  z-index: 2;
}
.tl-year { font-size: 15px; font-weight: 700; color: var(--brand); }
.tl-item h4 { font-size: 20px; color: var(--ink); margin: 4px 0 8px; }
.tl-item p { color: var(--muted); font-size: 15px; }

/* ---------- 案例墙 ---------- */
.cases {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
.case {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 28px 18px;
  text-align: center;
  font-weight: 700;
  color: var(--ink);
  font-size: 17px;
  transition: transform .25s, box-shadow .25s, background .25s, color .25s;
}
.case:hover { background: var(--grad); color: #fff; transform: translateY(-4px); box-shadow: var(--shadow); }

/* ---------- 价值观 ---------- */
.value-box {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 60px;
  align-items: center;
}
.value-text h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; color: var(--ink); line-height: 1.25; }
.value-text p { color: var(--muted); font-size: 17px; margin-top: 20px; }
.value-cards { display: grid; gap: 16px; }
.value-card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 24px 26px;
}
.value-card h4 { color: var(--ink); font-size: 18px; }
.value-card p { color: var(--muted); font-size: 14px; margin-top: 6px; }

/* ---------- 资质荣誉 ---------- */
.honors { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.honor {
  background: var(--grad-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px 30px;
  text-align: center;
}
.honor .ic { font-size: 30px; margin-bottom: 14px; }
.honor h4 { color: var(--ink); font-size: 18px; font-weight: 700; }
.honor p { color: var(--muted); font-size: 14px; margin-top: 8px; }

/* ---------- CTA 区 ---------- */
.cta {
  background: var(--bg-dark);
  border-radius: 28px;
  padding: 80px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta::after {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(600px 300px at 20% 0%, rgba(79,70,229,.35), transparent 60%),
              radial-gradient(500px 300px at 90% 100%, rgba(6,182,212,.3), transparent 60%);
}
.cta > * { position: relative; z-index: 2; }
.cta h2 { color: #fff; font-size: clamp(28px, 4vw, 42px); font-weight: 800; }
.cta p { color: #cbd5e1; font-size: 18px; margin: 18px auto 34px; max-width: 560px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg-dark); color: #94a3b8; padding: 64px 0 30px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; }
.footer-grid .brand { color: #fff; margin-bottom: 16px; }
.footer-grid p { font-size: 14px; line-height: 1.9; }
.footer-col h5 { color: #fff; font-size: 16px; margin-bottom: 18px; font-weight: 700; }
.footer-col a { display: block; font-size: 14px; padding: 6px 0; transition: color .2s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  margin-top: 48px; padding-top: 24px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px;
  font-size: 13px;
}
.footer-left { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; }
.footer-icp { color: #9aa1b3; }
.footer-icp:hover { color: #fff; }

/* ---------- 页面头图（子页） ---------- */
.page-hero {
  padding: 110px 0 70px;
  background:
    radial-gradient(700px 400px at 85% -20%, rgba(6,182,212,.14), transparent 60%),
    radial-gradient(700px 400px at 0% 0%, rgba(79,70,229,.14), transparent 55%),
    var(--bg-soft);
  text-align: center;
}
.page-hero h1 { font-size: clamp(32px, 5vw, 52px); font-weight: 800; color: var(--ink); letter-spacing: -.5px; }
.page-hero p { color: var(--muted); font-size: 17px; margin-top: 16px; }

/* ---------- 服务详情 ---------- */
.service-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  padding: 56px 0;
  border-bottom: 1px solid var(--line);
}
.service-row:last-child { border-bottom: none; }
.service-row.reverse .service-text { order: 2; }
.service-text .tag {
  display: inline-block;
  font-size: 13px; font-weight: 700; letter-spacing: 1px;
  color: var(--brand); background: var(--grad-soft);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 16px;
}
.service-text h2 { font-size: clamp(24px, 3vw, 34px); font-weight: 800; color: var(--ink); }
.service-text p { color: var(--muted); margin: 16px 0 22px; }
.service-list { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 20px; }
.service-list li { display: flex; align-items: flex-start; gap: 10px; font-size: 15px; color: var(--text); }
.service-list li::before { content: "✓"; color: var(--brand); font-weight: 800; }
.service-visual {
  background: var(--grad-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-height: 320px;
  display: grid; place-items: center;
  position: relative;
  overflow: hidden;
}
.service-visual .big-icon { font-size: 90px; filter: drop-shadow(0 10px 20px rgba(79,70,229,.25)); }

/* ---------- 联系页 ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 50px; align-items: start; }
.contact-info .info-item {
  display: flex; gap: 16px; align-items: flex-start;
  padding: 22px 0; border-bottom: 1px solid var(--line);
}
.contact-info .info-item:last-child { border-bottom: none; }
.contact-info .ic {
  width: 46px; height: 46px; flex: none;
  border-radius: 12px; background: var(--grad-soft);
  display: grid; place-items: center; color: var(--brand); font-size: 20px;
}
.contact-info .ic-t { font-weight: 700; color: var(--ink); }
.contact-info .ic-d { color: var(--muted); font-size: 15px; }

.form-card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 40px;
  box-shadow: var(--shadow-sm);
}
.form-card h3 { font-size: 22px; color: var(--ink); margin-bottom: 24px; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.field input, .field textarea, .field select {
  width: 100%; padding: 13px 16px;
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  font-family: inherit; font-size: 15px; color: var(--text);
  background: var(--bg-soft);
  transition: border-color .2s, box-shadow .2s;
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(79,70,229,.12); background: #fff;
}
.field textarea { resize: vertical; min-height: 120px; }
.form-note { font-size: 13px; color: var(--muted); margin-top: 14px; }
.form-success {
  display: none;
  background: #ecfdf5; border: 1px solid #a7f3d0; color: #047857;
  padding: 14px 18px; border-radius: var(--radius-sm); margin-bottom: 18px; font-size: 14px;
}

.map-box {
  margin-top: 50px;
  height: 360px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: #f1f5f9;
  overflow: hidden;
  position: relative;
}
.map-box > div,
.map-box > canvas {
  width: 100% !important;
  height: 100% !important;
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .grid-3, .cases, .adv-grid, .honors { grid-template-columns: repeat(2, 1fr); }
  .value-box, .service-row, .service-row.reverse .service-text, .contact-grid { grid-template-columns: 1fr; }
  .service-row.reverse .service-text { order: 0; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); gap: 30px 16px; }
}
@media (max-width: 680px) {
  .section { padding: 70px 0; }
  .nav-links, .nav-cta .btn { display: none; }
  .menu-toggle { display: flex; }
  .nav-links.open {
    display: flex; flex-direction: column; gap: 0;
    position: absolute; top: 72px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 10px 24px 20px;
  }
  .nav-links.open a { padding: 14px 0; border-bottom: 1px solid var(--line); }
  .grid-3, .cases, .adv-grid, .honors, .service-list { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .stats { padding: 36px 24px; }
  .form-card { padding: 28px 22px; }
}

/* ---------- Logo 图片 ---------- */
.brand .logo-img {
  width: 38px; height: 38px;
  border-radius: 11px;
  object-fit: contain;
  flex-shrink: 0;
}