/* ===== 设计变量 ===== */
:root {
  --blue: #2f7bff;
  --cyan: #19d8c8;
  --ink: #0e1726;
  --ink-2: #3a4658;
  --muted: #6b7689;
  --line: #e6ebf3;
  --bg: #ffffff;
  --bg-alt: #f5f8ff;
  --radius: 16px;
  --maxw: 1180px;
  --shadow: 0 18px 40px -20px rgba(20, 50, 110, 0.28);
  --shadow-sm: 0 8px 24px -12px rgba(20, 50, 110, 0.22);
  --grad: linear-gradient(120deg, #2f7bff, #19d8c8);
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

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

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-size: 15px; font-weight: 600; padding: 12px 24px; border-radius: 999px;
  border: 1px solid transparent; cursor: pointer; transition: .25s ease; white-space: nowrap;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.btn-outline { border-color: var(--blue); color: var(--blue); }
.btn-outline:hover { background: var(--blue); color: #fff; }
.btn-ghost { color: var(--ink-2); }
.btn-ghost:hover { color: var(--blue); }
.btn-block { width: 100%; }

/* ===== 导航 ===== */
.navbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82); backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent; transition: .3s;
}
.navbar.scrolled { border-color: var(--line); box-shadow: 0 6px 24px -18px rgba(20,50,110,.4); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { display: flex; }
.brand-text { font-weight: 800; font-size: 19px; letter-spacing: .5px; line-height: 1.1; display: flex; flex-direction: column; }
.brand-text small { font-size: 10px; font-weight: 600; color: var(--muted); letter-spacing: 2px; }
.nav-links { display: flex; align-items: center; gap: 26px; }
.nav-links a { font-size: 15px; color: var(--ink-2); font-weight: 500; transition: .2s; position: relative; }
.nav-links a:not(.btn)::after {
  content: ""; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
  background: var(--grad); transition: .25s;
}
.nav-links a:not(.btn):hover::after, .nav-links a.active::after { width: 100%; }
.nav-links a:hover, .nav-links a.active { color: var(--blue); }
.nav-cta { padding: 9px 18px; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; transition: .3s; }

/* ===== Hero ===== */
.hero { position: relative; overflow: hidden; padding: 80px 0 90px; }
.hero-bg { position: absolute; inset: 0; z-index: 0; }
.orb { position: absolute; border-radius: 50%; filter: blur(60px); opacity: .35; }
.orb-1 { width: 420px; height: 420px; background: #2f7bff; top: -120px; right: -80px; }
.orb-2 { width: 360px; height: 360px; background: #19d8c8; bottom: -140px; left: -100px; opacity: .25; }
.grid-line {
  position: absolute; inset: 0;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 46px 46px; opacity: .35;
  mask-image: radial-gradient(circle at 70% 30%, #000, transparent 70%);
}
.hero-inner { position: relative; z-index: 1; display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; }
.tag {
  display: inline-block; font-size: 13px; font-weight: 600; color: var(--blue);
  background: #eaf1ff; padding: 6px 14px; border-radius: 999px; margin-bottom: 18px;
}
.hero h1 { font-size: clamp(34px, 5vw, 56px); line-height: 1.15; font-weight: 800; letter-spacing: -1px; }
.hero h1 .grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lead { color: var(--ink-2); font-size: 17px; margin: 22px 0 30px; max-width: 540px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 34px; margin-top: 44px; flex-wrap: wrap; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 30px; font-weight: 800; color: var(--ink); }
.hero-stats span { font-size: 13px; color: var(--muted); }
.hero-visual { display: flex; justify-content: center; }
.hero-art { width: 100%; max-width: 440px; filter: drop-shadow(0 24px 40px rgba(20,50,110,.18)); }

/* ===== 通用 section ===== */
.section { padding: 84px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { max-width: 720px; margin: 0 auto 52px; text-align: center; }
.eyebrow { font-size: 13px; font-weight: 700; letter-spacing: 2px; color: var(--blue); text-transform: uppercase; }
.section-head h2 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; margin: 12px 0 14px; letter-spacing: -.5px; }
.section-head p { color: var(--muted); font-size: 16px; }

/* ===== 关于我们 ===== */
.about-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.about-card { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px; transition: .3s; }
.about-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.about-icon { width: 48px; height: 48px; border-radius: 12px; display: grid; place-items: center; font-size: 22px; color: #fff; background: var(--grad); margin-bottom: 16px; }
.about-card h3 { font-size: 17px; margin-bottom: 8px; }
.about-card p { color: var(--muted); font-size: 14.5px; }

/* ===== 核心业务卡片 ===== */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px 26px; transition: .3s; position: relative; overflow: hidden; }
.card::before { content: ""; position: absolute; inset: 0 0 auto 0; height: 4px; background: var(--grad); opacity: 0; transition: .3s; }
.card:hover { transform: translateY(-8px); box-shadow: var(--shadow); }
.card:hover::before { opacity: 1; }
.card-ic {
  width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center; font-size: 26px;
  background: linear-gradient(135deg, var(--c1), var(--c2)); margin-bottom: 18px;
}
.card h3 { font-size: 18px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

/* ===== 解决方案 ===== */
.solutions { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.sol { display: flex; gap: 20px; align-items: flex-start; background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 28px; transition: .3s; }
.sol:hover { box-shadow: var(--shadow); border-color: transparent; transform: translateY(-4px); }
.sol-num { font-size: 30px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; font-family: var(--font); flex-shrink: 0; }
.sol-body h3 { font-size: 18px; margin-bottom: 6px; }
.sol-body p { color: var(--muted); font-size: 15px; }

/* ===== 客户案例 ===== */
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 26px; display: flex; flex-direction: column; gap: 12px; transition: .3s; position: relative; }
.case:hover { transform: translateY(-8px); box-shadow: var(--shadow); border-color: transparent; }
.case-tag { align-self: flex-start; font-size: 12px; font-weight: 600; color: var(--blue); background: #eaf1ff; padding: 4px 12px; border-radius: 999px; }
.case h3 { font-size: 18px; }
.case p { color: var(--muted); font-size: 14.5px; flex: 1; }
.case-metric { font-size: 14px; font-weight: 700; color: #0f9d77; background: #e7f8f1; align-self: flex-start; padding: 6px 12px; border-radius: 10px; }

/* ===== 新闻 ===== */
.news { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.news-item { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 24px; transition: .3s; }
.news-item:hover { box-shadow: var(--shadow); transform: translateY(-4px); }
.news-item time { font-size: 13px; color: var(--blue); font-weight: 600; }
.news-item h3 { font-size: 17px; margin: 10px 0 8px; line-height: 1.4; }
.news-item p { color: var(--muted); font-size: 14.5px; }

/* ===== 联系我们 ===== */
.contact { background: linear-gradient(180deg, #0e1726, #16264a); color: #fff; }
.contact .eyebrow { color: var(--cyan); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.contact-info h2 { font-size: clamp(26px, 3.2vw, 36px); margin: 10px 0 14px; }
.contact-info p { color: #b9c4d6; font-size: 16px; max-width: 440px; }
.info-list { list-style: none; margin-top: 24px; display: flex; flex-direction: column; gap: 14px; }
.info-list li { display: flex; align-items: center; gap: 12px; color: #d7deea; font-size: 15px; }
.info-list span { font-size: 18px; }
.contact-form { background: #fff; color: var(--ink); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 7px; color: var(--ink-2); }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line); border-radius: 10px; font-size: 15px;
  font-family: var(--font); transition: .2s; background: #fbfdff; color: var(--ink);
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(47,123,255,.15); }
.field textarea { resize: vertical; }
.form-tip { font-size: 14px; margin-top: 12px; min-height: 20px; }
.form-tip.ok { color: #0f9d77; }
.form-tip.err { color: #e23b3b; }

/* ===== 页脚 ===== */
.footer { background: #0a1120; color: #c4ccda; padding: 56px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 30px; padding-bottom: 40px; }
.footer-brand .brand-text { color: #fff; }
.footer-brand p { color: #8b97aa; font-size: 14px; margin-top: 12px; }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-col a { display: block; color: #9aa6b8; font-size: 14px; margin-bottom: 10px; transition: .2s; }
.footer-col a:hover { color: var(--cyan); }
.footer-mini { font-size: 13px; color: #8b97aa; margin-bottom: 12px; }
.qr { width: 70px; height: 70px; border-radius: 10px; background: #1b2436; display: grid; place-items: center; color: #6b7689; font-size: 12px; border: 1px dashed #2c3a52; }
.footer-bottom { border-top: 1px solid #1b2436; padding: 18px 24px; display: flex; justify-content: space-between; font-size: 13px; color: #6b7689; flex-wrap: wrap; gap: 8px; }

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed; right: 24px; bottom: 24px; width: 46px; height: 46px; border-radius: 50%;
  background: var(--grad); color: #fff; display: grid; place-items: center; font-size: 20px;
  box-shadow: var(--shadow); opacity: 0; pointer-events: none; transition: .3s; z-index: 40;
}
.back-top.show { opacity: 1; pointer-events: auto; }
.back-top:hover { transform: translateY(-3px); }

/* ===== 滚动进场动画 ===== */
.reveal { opacity: 0; transform: translateY(28px); transition: .7s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { order: -1; }
  .about-grid { grid-template-columns: repeat(2, 1fr); }
  .cards, .cases, .news { grid-template-columns: repeat(2, 1fr); }
  .solutions { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 680px) {
  .nav-links {
    position: absolute; top: 70px; left: 0; right: 0; background: #fff; flex-direction: column;
    gap: 0; padding: 10px 0; border-bottom: 1px solid var(--line); box-shadow: var(--shadow-sm);
    transform: translateY(-12px); opacity: 0; pointer-events: none; transition: .25s;
  }
  .nav-links.open { transform: none; opacity: 1; pointer-events: auto; }
  .nav-links a { width: 100%; padding: 13px 24px; }
  .nav-links a:not(.btn)::after { display: none; }
  .nav-cta { margin: 8px 24px; text-align: center; }
  .nav-toggle { display: flex; }
  .cards, .cases, .news, .about-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .hero-stats { gap: 22px; }
  .section { padding: 60px 0; }
}