:root {
  --primary: #3860f4;
  --primary-dark: #2a4ad4;
  --primary-light: #eef2ff;
  --text: #1a1f36;
  --text-muted: #5a6278;
  --bg: #ffffff;
  --bg-alt: #f7f9fc;
  --border: #e8ecf4;
  --shadow: 0 4px 24px rgba(56, 96, 244, 0.08);
  --shadow-lg: 0 12px 40px rgba(56, 96, 244, 0.12);
  --radius: 12px;
  --header-h: 72px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s;
}

.header.scrolled {
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-img {
  height: 36px;
  width: auto;
  border-radius: 6px;
  object-fit: contain;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.logo-sub {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav a {
  font-size: 15px;
  color: var(--text-muted);
  transition: color 0.2s;
  position: relative;
}

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

.nav a.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

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

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: 0.3s;
}

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-h);
  background: linear-gradient(135deg, #f0f4ff 0%, #ffffff 50%, #f7f9ff 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -200px;
  right: -200px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(56, 96, 244, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -100px;
  left: -100px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(56, 96, 244, 0.05) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 80px 0;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 13px;
  font-weight: 500;
  border-radius: 20px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--text) 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: clamp(16px, 2.5vw, 20px);
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.25s;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 16px rgba(56, 96, 244, 0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(56, 96, 244, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary-light);
}

/* Section common */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-header p {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.about-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all 0.3s;
}

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

.about-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  opacity: 0.3;
  margin-bottom: 12px;
}

.about-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.about-card p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
}

/* Services */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 28px;
  text-align: center;
  transition: all 0.3s;
}

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

.service-icon {
  font-size: 40px;
  margin-bottom: 20px;
}

.service-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

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

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: all 0.3s;
}

.contact-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
}

.contact-icon {
  width: 48px;
  height: 48px;
  background: var(--primary-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 20px;
}

.contact-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-muted);
}

.contact-card p {
  font-size: 15px;
  color: var(--text);
  line-height: 1.6;
}

.contact-card a {
  color: var(--primary);
}

.contact-card a:hover {
  text-decoration: underline;
}

/* Footer */
.footer {
  background: #0d1a35;
  color: rgba(255, 255, 255, 0.8);
  padding: 40px 0;
  text-align: center;
}

.footer p {
  font-size: 14px;
  line-height: 2;
}

.footer a {
  color: rgba(255, 255, 255, 0.8);
  transition: color 0.2s;
}

.footer a:hover {
  color: #fff;
}

/* Animations */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
  }

  .services-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s;
  }

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

  .nav a {
    padding: 14px 0;
    width: 100%;
    text-align: center;
    border-bottom: 1px solid var(--border);
  }

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

  .menu-toggle {
    display: flex;
  }

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

  .menu-toggle.active span:nth-child(2) {
    opacity: 0;
  }

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

  .section {
    padding: 60px 0;
  }

  .hero-inner {
    padding: 60px 0;
  }
}