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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --text: #1e293b;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 24px rgba(37, 99, 235, 0.08);
  --radius: 12px;
  --header-h: 72px;
}

html {
  scroll-behavior: smooth;
}

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

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  border-radius: 8px;
  font-weight: 800;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

.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(--text);
  border-radius: 2px;
  transition: 0.3s;
}

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

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 70% 20%, rgba(37, 99, 235, 0.12) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
    linear-gradient(180deg, #f0f5ff 0%, #ffffff 100%);
  z-index: -1;
}

.hero-content {
  padding: 80px 24px;
}

.hero-tag {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--text-muted);
  max-width: 540px;
  margin-bottom: 36px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
}

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

.btn-outline:hover {
  background: rgba(37, 99, 235, 0.06);
}

.btn-full {
  width: 100%;
}

/* Sections */
.section {
  padding: 96px 0;
}

.section-header {
  margin-bottom: 48px;
}

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

.section-label {
  display: inline-block;
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 800;
  line-height: 1.3;
}

.section-desc {
  color: var(--text-muted);
  margin-top: 12px;
  font-size: 1.05rem;
}

/* About */
.about {
  background: var(--bg-alt);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 1.05rem;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.stat-item {
  background: var(--bg);
  padding: 28px 20px;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: var(--shadow);
}

.stat-num {
  display: block;
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
}

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

.service-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all 0.25s;
}

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

.service-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.service-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.service-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* Scope */
.scope {
  padding: 64px 0;
  background: var(--bg-alt);
}

.scope-box {
  background: var(--bg);
  border-left: 4px solid var(--primary);
  padding: 32px 36px;
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow);
}

.scope-box h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  color: var(--primary);
}

.scope-box p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

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

.contact-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.contact-value {
  font-size: 1.05rem;
  font-weight: 600;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-form input,
.contact-form textarea {
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--primary);
}

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

/* Footer */
.footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 32px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
}

.footer-brand .logo-icon {
  width: 32px;
  height: 32px;
  font-size: 0.95rem;
}

.footer-copy {
  font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 992px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

  .nav-links {
    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;
    transition: 0.3s;
    pointer-events: none;
  }

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

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

  .nav-links a {
    display: block;
    padding: 14px 0;
  }

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

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }

  .section {
    padding: 64px 0;
  }
}

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

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}