/* 南通大数洞察网络科技有限公司 - 企业官网样式 */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #06b6d4;
  --dark: #0b1220;
  --dark-2: #101a30;
  --text: #1e293b;
  --text-light: #64748b;
  --bg-light: #f4f7fc;
  --white: #ffffff;
  --radius: 12px;
  --shadow: 0 8px 30px rgba(15, 30, 60, .08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  line-height: 1.7;
}

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

.container { width: min(1180px, 92%); margin: 0 auto; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  transition: all .25s;
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 8px 20px rgba(37, 99, 235, .35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(37, 99, 235, .45); }
.btn-ghost {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, .5);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .12); }

/* ===== 顶部导航 ===== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(11, 18, 32, .85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  font-size: 18px;
}
.logo-mark {
  width: 36px; height: 36px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  font-size: 18px;
  color: #fff;
}
.logo small { display: block; font-size: 11px; font-weight: 400; color: #93a4c3; }
.nav-links { display: flex; gap: 34px; }
.nav-links a {
  color: #cbd5e1;
  font-size: 15px;
  transition: color .2s;
}
.nav-links a:hover, .nav-links a.active { color: #fff; }
.nav-toggle { display: none; background: none; border: none; color: #fff; font-size: 24px; cursor: pointer; }

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 160px 0 110px;
  background:
    radial-gradient(ellipse 60% 50% at 70% 20%, rgba(37, 99, 235, .35), transparent),
    radial-gradient(ellipse 50% 40% at 20% 80%, rgba(6, 182, 212, .2), transparent),
    var(--dark);
  color: #fff;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}
.hero-inner { position: relative; display: grid; grid-template-columns: 1.15fr .85fr; gap: 50px; align-items: center; }
.hero h1 { font-size: 42px; line-height: 1.35; margin-bottom: 20px; }
.hero h1 span {
  background: linear-gradient(90deg, #60a5fa, #22d3ee);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.sub { color: #a5b4cf; font-size: 18px; margin-bottom: 34px; max-width: 560px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 40px; margin-top: 48px; }
.hero-stats .num { font-size: 32px; font-weight: 800; color: #22d3ee; }
.hero-stats .label { color: #8fa0be; font-size: 14px; }

/* hero 右侧代码卡片 */
.hero-card {
  background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: var(--radius);
  padding: 24px;
  font-family: Consolas, Monaco, monospace;
  font-size: 14px;
  color: #9fb3d9;
  box-shadow: var(--shadow);
}
.hero-card .dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 6px; }
.hero-card .line { margin: 8px 0; }
.hero-card .k { color: #7dd3fc; }
.hero-card .s { color: #86efac; }
.hero-card .c { color: #64748b; }

/* ===== 通用区块 ===== */
.section { padding: 90px 0; }
.section.alt { background: var(--bg-light); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section-head .tag {
  display: inline-block;
  color: var(--primary);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 2px;
  margin-bottom: 12px;
}
.section-head h2 { font-size: 32px; margin-bottom: 14px; }
.section-head p { color: var(--text-light); }

/* ===== 卡片网格 ===== */
.grid { display: grid; gap: 28px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 34px 30px;
  box-shadow: var(--shadow);
  border: 1px solid #e8eef7;
  transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 16px 40px rgba(15, 30, 60, .14); }
.card .icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(37, 99, 235, .12), rgba(6, 182, 212, .12));
  display: flex; align-items: center; justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}
.card h3 { font-size: 20px; margin-bottom: 10px; }
.card p { color: var(--text-light); font-size: 15px; }
.card ul { margin-top: 14px; }
.card ul li { color: var(--text-light); font-size: 14px; padding: 4px 0 4px 20px; position: relative; }
.card ul li::before {
  content: "✓";
  position: absolute; left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* ===== 流程 ===== */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.step { text-align: center; padding: 30px 20px; background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow); }
.step .no {
  width: 46px; height: 46px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  display: flex; align-items: center; justify-content: center;
}
.step h4 { font-size: 17px; margin-bottom: 8px; }
.step p { color: var(--text-light); font-size: 14px; }

/* ===== 页面小标题 (子页 hero) ===== */
.page-hero {
  padding: 150px 0 70px;
  background:
    radial-gradient(ellipse 60% 60% at 60% 0%, rgba(37, 99, 235, .3), transparent),
    var(--dark);
  color: #fff;
  text-align: center;
}
.page-hero h1 { font-size: 34px; margin-bottom: 12px; }
.page-hero p { color: #a5b4cf; }

/* ===== 联系 ===== */
.contact-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact-info .item {
  display: flex; gap: 16px;
  align-items: flex-start;
  background: var(--white);
  border-radius: var(--radius);
  padding: 22px 26px;
  box-shadow: var(--shadow);
  margin-bottom: 18px;
}
.contact-info .icon {
  width: 44px; height: 44px; flex: none;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(37, 99, 235, .12), rgba(6, 182, 212, .12));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
}
.contact-info h4 { font-size: 16px; margin-bottom: 2px; }
.contact-info p { color: var(--text-light); font-size: 15px; }
.contact-form { background: var(--white); border-radius: var(--radius); padding: 34px; box-shadow: var(--shadow); }
.contact-form h3 { margin-bottom: 20px; }
.form-row { margin-bottom: 18px; }
.form-row label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.form-row input, .form-row textarea, .form-row select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #d7e0ee;
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  outline: none;
  transition: border .2s;
}
.form-row input:focus, .form-row textarea:focus { border-color: var(--primary); }
.form-row textarea { min-height: 120px; resize: vertical; }
.form-tip { color: var(--text-light); font-size: 13px; margin-top: 12px; }

/* ===== 页脚 ===== */
.footer { background: var(--dark); color: #93a4c3; padding: 60px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer h4 { color: #fff; font-size: 16px; margin-bottom: 16px; }
.footer p, .footer li { font-size: 14px; padding: 4px 0; }
.footer a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .08);
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
  color: #64748b;
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-card { display: none; }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .contact-wrap { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .nav-links {
    display: none;
    position: absolute;
    top: 68px; left: 0; right: 0;
    background: var(--dark-2);
    flex-direction: column;
    padding: 20px 5%;
    gap: 18px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .hero h1 { font-size: 30px; }
}