/* ============ 基础 ============ */
:root {
  --primary: #1e5eff;
  --primary-dark: #1246c8;
  --dark: #0b1526;
  --text: #333;
  --text-light: #777;
  --bg-light: #f5f8fc;
  --radius: 12px;
}
* { 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; }
img { max-width: 100%; }
.container { width: min(1180px, 92%); margin: 0 auto; }

/* ============ 顶部通栏 ============ */
.topbar {
  background: var(--dark);
  color: #9fb3d1;
  font-size: 13px;
}
.topbar-inner {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  gap: 12px;
  flex-wrap: wrap;
}

/* ============ 导航 ============ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.3s;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 46px; height: 46px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 18px;
  letter-spacing: 1px;
}
.logo-mark svg { display: block; }
.logo-text { line-height: 1.3; }
.logo-text strong { display: block; font-size: 19px; color: var(--dark); }
.logo-text span { font-size: 11px; color: var(--text-light); letter-spacing: 2px; }

.nav { display: flex; gap: 34px; }
.nav a {
  font-size: 15px;
  color: var(--text);
  position: relative;
  padding: 6px 0;
  transition: color 0.25s;
}
.nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  background: var(--primary);
  transition: width 0.25s;
}
.nav a:hover, .nav a.active { color: var(--primary); }
.nav a:hover::after, .nav a.active::after { width: 100%; }

.menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.menu-btn span {
  width: 24px; height: 2px;
  background: var(--dark);
  transition: 0.3s;
}

/* ============ 首屏 ============ */
.hero {
  position: relative;
  color: #fff;
  overflow: hidden;
  background: var(--dark);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 75% 20%, rgba(30, 94, 255, 0.35), transparent 55%),
    radial-gradient(ellipse at 15% 85%, rgba(20, 184, 166, 0.18), transparent 50%),
    linear-gradient(120deg, #0b1526 0%, #101f3d 100%);
}
.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 48px 48px;
}
.hero-content {
  position: relative;
  padding: 120px 0 140px;
  max-width: 720px;
}
.hero-tag {
  display: inline-block;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 999px;
  padding: 4px 16px;
  font-size: 13px;
  color: #c8d6ee;
  margin-bottom: 22px;
}
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.25;
  margin-bottom: 20px;
}
.hero-desc {
  font-size: 17px;
  color: #b9c8e2;
  margin-bottom: 36px;
}
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 13px 34px;
  border-radius: 8px;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: 0.25s;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  box-shadow: 0 6px 18px rgba(30, 94, 255, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(30, 94, 255, 0.45); }
.btn-ghost {
  border: 1px solid rgba(255,255,255,0.45);
  color: #fff;
  background: transparent;
}
.btn-ghost:hover { background: rgba(255,255,255,0.1); }

/* ============ 数据条 ============ */
.stats {
  background: #fff;
  box-shadow: 0 8px 30px rgba(0,0,0,0.05);
  position: relative;
  z-index: 2;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 34px 0;
  text-align: center;
}
.stat strong {
  display: block;
  font-size: 34px;
  color: var(--primary);
  font-weight: 700;
}
.stat span { font-size: 14px; color: var(--text-light); }

/* ============ 通用区块 ============ */
.section { padding: 90px 0; }
.section-head { text-align: center; margin-bottom: 56px; }
.section-head h2 {
  font-size: 32px;
  color: var(--dark);
  position: relative;
  display: inline-block;
  padding-bottom: 14px;
}
.section-head h2::after {
  content: "";
  position: absolute;
  left: 50%; bottom: 0;
  transform: translateX(-50%);
  width: 44px; height: 3px;
  border-radius: 2px;
  background: var(--primary);
}
.section-sub {
  color: #b3c2d8;
  font-size: 14px;
  letter-spacing: 4px;
  text-transform: uppercase;
  margin-top: 6px;
}

/* ============ 关于 ============ */
.about { background: var(--bg-light); }
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-text h3 { font-size: 24px; color: var(--dark); margin-bottom: 18px; }
.about-text p { color: var(--text-light); margin-bottom: 14px; }
.about-list {
  list-style: none;
  margin-top: 20px;
  background: #fff;
  border-radius: var(--radius);
  padding: 18px 24px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.04);
}
.about-list li {
  padding: 7px 0;
  border-bottom: 1px dashed #e4eaf3;
  font-size: 14.5px;
  color: var(--text);
}
.about-list li:last-child { border-bottom: none; }
.about-card {
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.about-card-item {
  background: #fff;
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  gap: 16px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.04);
  transition: transform 0.25s, box-shadow 0.25s;
}
.about-card-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 26px rgba(0,0,0,0.08);
}
.about-card-item .icon {
  width: 48px; height: 48px;
  flex-shrink: 0;
  border-radius: 10px;
  background: rgba(30, 94, 255, 0.08);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
}
.about-card-item .icon svg { display: block; }
.about-card-item h4 { font-size: 16px; color: var(--dark); margin-bottom: 4px; }
.about-card-item p { font-size: 14px; color: var(--text-light); }

/* ============ 业务 ============ */
.business-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.biz-card {
  background: #fff;
  border: 1px solid #e9eef7;
  border-radius: var(--radius);
  padding: 34px 28px;
  transition: 0.3s;
}
.biz-card:hover {
  border-color: var(--primary);
  box-shadow: 0 14px 32px rgba(30, 94, 255, 0.12);
  transform: translateY(-6px);
}
.biz-icon {
  width: 60px; height: 60px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(30,94,255,0.1), rgba(30,94,255,0.04));
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px;
}
.biz-icon svg { display: block; }
.biz-card h3 { font-size: 19px; color: var(--dark); margin-bottom: 10px; }
.biz-card p { font-size: 14.5px; color: var(--text-light); }

/* ============ 优势 ============ */
.strength { background: var(--dark); color: #fff; }
.strength .section-head h2 { color: #fff; }
.strength-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 26px;
}
.strength-item {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.09);
  border-radius: var(--radius);
  padding: 30px 24px;
  transition: 0.3s;
}
.strength-item:hover {
  background: rgba(30, 94, 255, 0.14);
  border-color: rgba(30, 94, 255, 0.4);
  transform: translateY(-6px);
}
.strength-item strong {
  font-size: 30px;
  color: var(--primary);
  opacity: 0.9;
}
.strength-item h3 { font-size: 17px; margin: 12px 0 8px; }
.strength-item p { font-size: 13.5px; color: #9fb3d1; }

/* ============ 合作领域 ============ */
.case-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 26px;
}
.case-item {
  position: relative;
  border-radius: var(--radius);
  padding: 42px 26px;
  color: #fff;
  overflow: hidden;
  background: linear-gradient(135deg, var(--c1), var(--c2));
  transition: transform 0.3s, box-shadow 0.3s;
}
.case-item:hover { transform: translateY(-6px); box-shadow: 0 16px 34px rgba(0,0,0,0.2); }
.case-item::after {
  content: "";
  position: absolute;
  right: -30px; bottom: -30px;
  width: 120px; height: 120px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
}
.case-item h3 { font-size: 20px; margin-bottom: 8px; position: relative; z-index: 1; }
.case-item p { font-size: 13.5px; opacity: 0.85; position: relative; z-index: 1; }

/* ============ 联系 ============ */
.contact { background: var(--bg-light); }
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}
.contact-item {
  display: flex;
  gap: 16px;
  margin-bottom: 26px;
}
.contact-item .icon {
  width: 48px; height: 48px;
  flex-shrink: 0;
  border-radius: 10px;
  background: rgba(30, 94, 255, 0.08);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
}
.contact-item .icon svg { display: block; }
.contact-item h4 { font-size: 16px; color: var(--dark); }
.contact-item p { font-size: 14.5px; color: var(--text-light); }

.contact-form {
  background: #fff;
  border-radius: var(--radius);
  padding: 34px;
  box-shadow: 0 6px 24px rgba(0,0,0,0.06);
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.contact-form h3 { font-size: 20px; color: var(--dark); }
.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid #dfe6f2;
  border-radius: 8px;
  padding: 12px 14px;
  font-size: 14.5px;
  font-family: inherit;
  outline: none;
  transition: border-color 0.25s;
  resize: vertical;
}
.contact-form input:focus,
.contact-form textarea:focus { border-color: var(--primary); }
.form-tip { font-size: 14px; color: #16a34a; min-height: 20px; }

/* ============ 页脚 ============ */
.footer {
  background: #08101f;
  color: #8ea3c2;
  padding: 56px 0 30px;
  font-size: 14px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.4fr;
  gap: 40px;
  align-items: start;
}
.footer-brand { display: flex; gap: 14px; align-items: center; }
.footer-brand strong { display: block; color: #fff; font-size: 16px; }
.footer-brand p { font-size: 13px; }
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links a:hover { color: #fff; }
.footer-copy { text-align: right; }
.footer-copy p { margin-bottom: 6px; }

/* ============ 响应式 ============ */
@media (max-width: 900px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .business-grid { grid-template-columns: repeat(2, 1fr); }
  .strength-grid, .case-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-copy { text-align: left; }
}
@media (max-width: 640px) {
  .nav {
    position: fixed;
    top: 72px;
    left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }
  .nav.open { max-height: 360px; }
  .nav a { padding: 14px 6%; border-bottom: 1px solid #f0f3f8; }
  .menu-btn { display: flex; }
  .business-grid, .strength-grid, .case-grid { grid-template-columns: 1fr; }
  .hero-content { padding: 80px 0 100px; }
  .section { padding: 64px 0; }
}