/* ===== 基础变量 ===== */
:root {
  --color-primary: #0066cc;
  --color-primary-dark: #004d99;
  --color-primary-light: #e6f0fa;
  --color-accent: #00b4d8;
  --color-text: #1a1a2e;
  --color-text-muted: #5a6270;
  --color-bg: #ffffff;
  --color-bg-alt: #f5f7fa;
  --color-border: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 20px rgba(0, 102, 204, 0.12);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --transition: 0.3s ease;
  --header-height: 72px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  overflow-x: hidden;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #fff;
}

.btn-full {
  width: 100%;
}

/* ===== 导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--color-text);
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 800;
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 15px;
  color: var(--color-text-muted);
  font-weight: 500;
  position: relative;
  transition: color var(--transition);
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition);
}

.nav-toggle.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== 首屏 ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #0a1628 0%, #0d3b6e 50%, #0066cc 100%);
  z-index: 0;
}

.hero-bg::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 80%, rgba(0, 180, 216, 0.25) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(0, 102, 204, 0.3) 0%, transparent 50%);
}

.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}

.hero-content {
  position: relative;
  z-index: 1;
  color: #fff;
  padding: 80px 24px;
  max-width: 1140px;
  margin: 0 auto;
  width: 100%;
}

.hero-tag {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 20px;
  font-size: 13px;
  letter-spacing: 1px;
  margin-bottom: 24px;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards;
}

.hero h1 {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.15s forwards;
}

.hero-desc {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.8);
  max-width: 560px;
  margin-bottom: 40px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.3s forwards;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 64px;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.45s forwards;
}

.hero-stats {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.8s ease 0.6s forwards;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-size: 36px;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
}

.stat-num::after {
  content: attr(data-suffix);
}

.stat-label {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 6px;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 通用区块 ===== */
.section {
  padding: 100px 0;
}

.section-header {
  margin-bottom: 56px;
}

.section-header.center {
  text-align: center;
}

.section-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  color: var(--color-text);
}

.section-sub {
  margin-top: 12px;
  color: var(--color-text-muted);
  font-size: 16px;
}

/* ===== 关于我们 ===== */
.about {
  background: var(--color-bg);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: 20px;
  font-size: 16px;
}

.about-text strong {
  color: var(--color-text);
}

.about-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.about-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all var(--transition);
}

.about-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.about-card-icon {
  font-size: 28px;
  margin-bottom: 12px;
}

.about-card h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 6px;
}

.about-card p {
  font-size: 14px;
  color: var(--color-text-muted);
}

/* ===== 核心业务 ===== */
.services {
  background: var(--color-bg-alt);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: all var(--transition);
  opacity: 0;
  transform: translateY(30px);
}

.service-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.service-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-6px);
}

.service-icon {
  width: 48px;
  height: 48px;
  background: var(--color-primary-light);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--color-primary);
}

.service-icon svg {
  width: 24px;
  height: 24px;
}

.service-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 12px;
}

.service-card p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* ===== 我们的优势 ===== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.advantage-item {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 36px;
  border-left: 3px solid var(--color-primary);
  background: var(--color-bg-alt);
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: all var(--transition);
  opacity: 0;
  transform: translateX(-20px);
}

.advantage-item.visible {
  opacity: 1;
  transform: translateX(0);
}

.advantage-item:hover {
  background: var(--color-primary-light);
}

.advantage-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--color-primary);
  opacity: 0.3;
  line-height: 1;
}

.advantage-item h3 {
  font-size: 18px;
  font-weight: 700;
}

.advantage-item p {
  font-size: 15px;
  color: var(--color-text-muted);
}

/* ===== 联系我们 ===== */
.contact {
  background: var(--color-bg-alt);
}

.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 8px;
}

.contact-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.contact-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.5px;
}

.contact-form {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow-sm);
}

.contact-form h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 28px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
  color: var(--color-text);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text);
  background: var(--color-bg);
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

.form-tip {
  margin-top: 12px;
  font-size: 14px;
  text-align: center;
  min-height: 20px;
}

.form-tip.success {
  color: #059669;
}

.form-tip.error {
  color: #dc2626;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 600;
  color: #fff;
}

.footer-copy {
  font-size: 13px;
}

.footer-beian {
  font-size: 13px;
}

.footer-beian a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
}

.footer-beian a:hover {
  color: #fff;
  text-decoration: underline;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 24px;
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-110%);
    opacity: 0;
    transition: all var(--transition);
    pointer-events: none;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-links li {
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links li:last-child {
    border-bottom: none;
  }

  .nav-links a {
    display: block;
    padding: 16px 0;
    font-size: 16px;
  }

  .about-grid,
  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-cards {
    grid-template-columns: 1fr 1fr;
  }

  .advantages-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    gap: 32px;
  }

  .contact-form {
    padding: 28px 24px;
  }
}

@media (max-width: 480px) {
  .services-grid {
    grid-template-columns: 1fr;
  }

  .about-cards {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}