/* ==========================================================
   北京启齐科技有限公司 - 企业官网样式
   主题：科技蓝 · 现代商务
   ========================================================== */

/* ---------- 设计变量 ---------- */
:root {
  --blue-600: #1d4ed8;
  --blue-500: #2563eb;
  --blue-400: #3b82f6;
  --blue-300: #60a5fa;
  --teal-500: #0d9488;
  --ink-900: #0b1526;
  --ink-800: #101d33;
  --ink-700: #1c2b45;
  --text-1: #0f172a;
  --text-2: #475569;
  --text-3: #94a3b8;
  --bg-1: #ffffff;
  --bg-2: #f5f8fd;
  --border: #e2e8f0;
  --radius: 14px;
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, .06);
  --shadow-md: 0 10px 30px rgba(29, 78, 216, .10);
  --container: 1140px;
  --nav-h: 72px;
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 8px); }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
  color: var(--text-1);
  background: var(--bg-1);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font: inherit; cursor: pointer; }

.container { max-width: var(--container); margin-inline: auto; padding-inline: 24px; }

/* 焦点可见性（无障碍） */
a:focus-visible, button:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--blue-500);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  padding: 13px 30px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  color: #fff;
  box-shadow: 0 8px 20px rgba(37, 99, 235, .35);
}
.btn-primary:hover { box-shadow: 0 12px 26px rgba(37, 99, 235, .45); }
.btn-ghost {
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, .45);
  background: rgba(255, 255, 255, .06);
  backdrop-filter: blur(4px);
}
.btn-ghost:hover { border-color: #fff; background: rgba(255, 255, 255, .14); }
.btn-light { background: #fff; color: var(--blue-600); box-shadow: var(--shadow-md); }
.btn-block { width: 100%; }

/* ---------- 导航 ---------- */
.navbar {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--nav-h);
  z-index: 100;
  transition: background .25s ease, box-shadow .25s ease;
}
.navbar.scrolled {
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 100%; }

.logo { display: flex; align-items: center; gap: 10px; }
.logo-mark {
  display: grid; place-items: center;
  width: 40px; height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  color: #fff; font-size: 20px; font-weight: 700;
  box-shadow: 0 4px 12px rgba(37, 99, 235, .35);
}
.logo-text { font-weight: 700; font-size: 18px; color: #fff; line-height: 1.2; display: flex; flex-direction: column; }
.logo-text small { font-size: 10px; font-weight: 500; letter-spacing: 2px; opacity: .75; }
.navbar.scrolled .logo-text { color: var(--text-1); }

.nav-links { display: flex; gap: 32px; }
.nav-links a {
  color: rgba(255, 255, 255, .85);
  font-size: 15px; font-weight: 500;
  position: relative; padding: 6px 0;
  transition: color .2s;
}
.navbar.scrolled .nav-links a { color: var(--text-2); }
.nav-links a::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  width: 0; height: 2px;
  background: linear-gradient(90deg, var(--blue-400), var(--blue-600));
  border-radius: 2px;
  transition: width .25s ease;
}
.nav-links a:hover, .nav-links a.active { color: #fff; }
.navbar.scrolled .nav-links a:hover, .navbar.scrolled .nav-links a.active { color: var(--blue-600); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

.nav-toggle { display: none; background: none; border: none; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: #fff; margin: 5px 0; border-radius: 2px; transition: .25s; }
.navbar.scrolled .nav-toggle span { background: var(--text-1); }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  background: linear-gradient(160deg, var(--ink-900) 0%, var(--ink-800) 55%, #12264d 100%);
  color: #fff;
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.glow { position: absolute; border-radius: 50%; filter: blur(90px); opacity: .5; }
.glow-1 { width: 520px; height: 520px; background: var(--blue-600); top: -140px; right: -120px; }
.glow-2 { width: 420px; height: 420px; background: #0ea5e9; bottom: -160px; left: -100px; opacity: .35; }
.grid-lines {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
}

.hero-content { position: relative; z-index: 1; }
.hero-tag {
  display: inline-block;
  padding: 7px 18px;
  border: 1px solid rgba(96, 165, 250, .45);
  border-radius: 999px;
  background: rgba(37, 99, 235, .16);
  color: var(--blue-300);
  font-size: 14px;
  letter-spacing: 1px;
  margin-bottom: 26px;
}
.hero h1 {
  font-size: clamp(34px, 5.2vw, 58px);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: 1px;
}
.gradient-text {
  background: linear-gradient(90deg, #60a5fa, #38bdf8 60%, #22d3ee);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  max-width: 640px;
  margin-top: 22px;
  font-size: 17px;
  color: rgba(226, 232, 240, .82);
}
.hero-actions { display: flex; gap: 16px; margin-top: 38px; flex-wrap: wrap; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 720px;
  margin-top: 64px;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, .14);
}
.hero-stats strong {
  display: block;
  font-size: 34px;
  font-weight: 800;
  background: linear-gradient(90deg, #93c5fd, #67e8f9);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-stats span { font-size: 13px; color: rgba(203, 213, 225, .8); }

/* ---------- 通用区块 ---------- */
.section { padding: 96px 0; }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section-tag {
  color: var(--blue-500);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 4px;
  margin-bottom: 10px;
}
.section-head h2 { font-size: clamp(26px, 3.4vw, 36px); font-weight: 800; }
.section-desc { margin-top: 14px; color: var(--text-2); font-size: 16px; }

/* ---------- 关于我们 ---------- */
.about { background: var(--bg-2); }
.about-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: start; }
.about-text h3 { font-size: 24px; margin-bottom: 18px; }
.about-text p { color: var(--text-2); margin-bottom: 14px; }
.about-text strong { color: var(--blue-600); }
.about-points { margin-top: 20px; }
.about-points li {
  position: relative;
  padding-left: 30px;
  margin-bottom: 12px;
  color: var(--text-2);
}
.about-points li::before {
  content: "✓";
  position: absolute; left: 0; top: 0;
  width: 21px; height: 21px;
  display: grid; place-items: center;
  background: rgba(37, 99, 235, .12);
  color: var(--blue-600);
  border-radius: 50%;
  font-size: 12px; font-weight: 700;
}
.about-cards { display: grid; gap: 18px; }
.mini-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 26px;
  display: flex;
  gap: 18px;
  align-items: flex-start;
  box-shadow: var(--shadow-sm);
  transition: transform .25s ease, box-shadow .25s ease;
}
.mini-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.mini-icon { font-size: 26px; line-height: 1; }
.mini-card h4 { font-size: 16px; color: var(--blue-600); margin-bottom: 4px; }
.mini-card p { font-size: 14px; color: var(--text-2); }

/* ---------- 业务服务 ---------- */
.service-group-title {
  display: flex; align-items: center; gap: 10px;
  font-size: 19px;
  margin: 0 0 24px;
}
.service-group-title + .cards-grid { margin-bottom: 52px; }
.dot { width: 10px; height: 10px; border-radius: 3px; background: linear-gradient(135deg, var(--blue-400), var(--blue-600)); }
.dot-teal { background: linear-gradient(135deg, #2dd4bf, var(--teal-500)); }

.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 28px;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: var(--blue-300); }
.card-icon {
  width: 52px; height: 52px;
  display: grid; place-items: center;
  border-radius: 13px;
  background: linear-gradient(135deg, rgba(37, 99, 235, .12), rgba(37, 99, 235, .05));
  color: var(--blue-600);
  margin-bottom: 20px;
}
.card-icon svg { width: 26px; height: 26px; }
.card-icon.icon-teal {
  background: linear-gradient(135deg, rgba(13, 148, 136, .12), rgba(13, 148, 136, .05));
  color: var(--teal-500);
}
.card h4 { font-size: 18px; margin-bottom: 10px; }
.card p { font-size: 14.5px; color: var(--text-2); }

/* ---------- 服务优势 ---------- */
.cases { background: var(--bg-2); }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.feature {
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 30px 26px;
  position: relative;
  overflow: hidden;
  transition: transform .25s ease, box-shadow .25s ease;
}
.feature:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.feature-num {
  font-size: 44px;
  font-weight: 800;
  background: linear-gradient(180deg, var(--blue-300), transparent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1;
  display: block;
  margin-bottom: 14px;
}
.feature h4 { font-size: 17px; margin-bottom: 8px; }
.feature p { font-size: 14px; color: var(--text-2); }

/* 合作流程 */
.process { margin-top: 72px; text-align: center; }
.process-title { font-size: 20px; margin-bottom: 34px; }
.process-steps {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 14px;
}
.process-steps li { position: relative; padding-top: 8px; }
.process-steps span {
  display: grid; place-items: center;
  width: 44px; height: 44px;
  margin: 0 auto 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  color: #fff; font-weight: 700;
  box-shadow: 0 6px 14px rgba(37, 99, 235, .3);
}
.process-steps strong { display: block; font-size: 15px; }
.process-steps p { font-size: 12.5px; color: var(--text-3); margin-top: 4px; }

/* ---------- 联系我们 ---------- */
.contact-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 48px; align-items: start; }
.contact-item { display: flex; gap: 18px; padding: 22px 0; border-bottom: 1px dashed var(--border); }
.contact-item:last-child { border-bottom: none; }
.contact-icon {
  flex: none;
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: 12px;
  background: rgba(37, 99, 235, .1);
  color: var(--blue-600);
}
.contact-icon svg { width: 22px; height: 22px; }
.contact-item h5 { font-size: 15px; margin-bottom: 2px; }
.contact-item p { font-size: 14px; color: var(--text-2); }

.contact-form {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-field { margin-bottom: 18px; }
.form-field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; }
.form-field label span { color: #ef4444; }
.form-field input, .form-field select, .form-field textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font: inherit;
  font-size: 14.5px;
  color: var(--text-1);
  background: #fff;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.form-field textarea { resize: vertical; }
.form-field input:focus, .form-field select:focus, .form-field textarea:focus {
  outline: none;
  border-color: var(--blue-500);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, .12);
}
.form-status { margin-top: 14px; font-size: 14px; text-align: center; min-height: 20px; }
.form-status.ok { color: #16a34a; }
.form-status.err { color: #ef4444; }

/* ---------- CTA 横幅 ---------- */
.cta-band {
  background:
    radial-gradient(ellipse 60% 120% at 80% 20%, rgba(56, 189, 248, .25), transparent),
    linear-gradient(120deg, var(--ink-900), #122a55);
  color: #fff;
  padding: 72px 0;
}
.cta-inner { text-align: center; }
.cta-inner h2 { font-size: clamp(24px, 3vw, 32px); }
.cta-inner p { margin: 12px 0 28px; color: rgba(203, 213, 225, .85); }

/* ---------- 页脚 ---------- */
.footer { background: var(--ink-900); color: rgba(203, 213, 225, .8); padding: 64px 0 0; }
.footer-inner {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding-bottom: 44px;
}
.footer-brand .logo-text { color: #fff; }
.footer-brand p { margin-top: 16px; font-size: 13px; line-height: 1.9; color: rgba(148, 163, 184, .9); }
.footer-col h5 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; padding: 5px 0; transition: color .2s; }
.footer-col a:hover { color: var(--blue-300); }
.footer-col p { font-size: 13.5px; padding: 4px 0; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .1);
  padding-top: 20px;
  padding-bottom: 24px;
  font-size: 12.5px;
  color: rgba(148, 163, 184, .7);
  text-align: center;
}
.footer-bottom p { margin-top: 4px; }

/* ---------- 滚动入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .about-grid, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .process-steps { grid-template-columns: repeat(3, 1fr); row-gap: 28px; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .section { padding: 72px 0; }
  .nav-toggle { display: block; }
  .nav-links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: #fff;
    box-shadow: var(--shadow-md);
    max-height: 0;
    overflow: hidden;
    transition: max-height .3s ease;
  }
  .nav-links.open { max-height: 320px; }
  .nav-links a { color: var(--text-1) !important; padding: 15px 24px; border-bottom: 1px solid var(--border); }
  .nav-links a::after { display: none; }
  .cards-grid, .feature-grid, .form-row { grid-template-columns: 1fr; }
  .process-steps { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .hero-actions .btn { width: 100%; text-align: center; }
}