/* ===== CSS 变量 ===== */
:root {
  --primary: #0EA5E9;
  --primary-light: #38BDF8;
  --primary-dark: #0284C7;
  --secondary: #F3F4F6;
  --text-dark: #1F2937;
  --text-gray: #6B7280;
  --text-light: #9CA3AF;
  --white: #FFFFFF;
  --border: #E5E7EB;
  --shadow: rgba(0, 0, 0, 0.08);
  --radius: 6px;
  --transition: 0.3s ease;
}

/* ===== 重置样式 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  background: var(--white);
}

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

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
}

/* ===== 布局 ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 50px;
}

.section-title h2 {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 12px;
}

.section-title p {
  font-size: 16px;
  color: var(--text-gray);
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--white);
  box-shadow: 0 1px 3px var(--shadow);
  z-index: 1000;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo img {
  height: 40px;
}

.logo span {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-dark);
}

.nav-links {
  display: flex;
  gap: 32px;
}

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

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

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.mobile-menu-btn span {
  width: 25px;
  height: 2px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero 区域 ===== */
.hero {
  padding: 140px 0 100px;
  background: linear-gradient(180deg, #F0F9FF 0%, var(--white) 100%);
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content h1 {
  font-size: 48px;
  font-weight: 800;
  color: var(--text-dark);
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-content h1 span {
  color: var(--primary);
}

.hero-content p {
  font-size: 18px;
  color: var(--text-gray);
  margin-bottom: 32px;
  line-height: 1.7;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

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

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

.btn-secondary {
  background: var(--white);
  color: var(--text-dark);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image .illustration {
  width: 100%;
  max-width: 480px;
  height: 360px;
  background: var(--white);
  border-radius: 12px;
  box-shadow: 0 10px 40px var(--shadow);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.hero-image .illustration-header {
  height: 40px;
  background: var(--secondary);
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 8px;
}

.hero-image .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
}

.hero-image .illustration-body {
  flex: 1;
  padding: 30px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.hero-image .card {
  background: #F8FAFC;
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}

.hero-image .card-icon {
  width: 48px;
  height: 48px;
  background: var(--primary-light);
  border-radius: 50%;
  margin: 0 auto 12px;
  opacity: 0.8;
}

/* ===== 服务特点 ===== */
.features {
  background: var(--white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: var(--primary-light);
  transform: translateY(-4px);
  box-shadow: 0 10px 30px var(--shadow);
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: #F0F9FF;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 24px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-dark);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-gray);
  line-height: 1.7;
}

/* ===== 关于我们 ===== */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-image {
  background: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 100%);
  border-radius: 12px;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--text-gray);
}

.about-text h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-dark);
}

.about-text p {
  color: var(--text-gray);
  margin-bottom: 20px;
  line-height: 1.8;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 32px;
}

.stat-item {
  text-align: center;
}

.stat-item .number {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
}

.stat-item .label {
  font-size: 14px;
  color: var(--text-gray);
}

/* ===== 服务列表 ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.service-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  transition: all var(--transition);
}

.service-card:hover {
  border-color: var(--primary-light);
  box-shadow: 0 8px 30px var(--shadow);
}

.service-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.service-icon {
  width: 48px;
  height: 48px;
  background: #F0F9FF;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.service-card h3 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-dark);
}

.service-card p {
  color: var(--text-gray);
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 20px;
}

.service-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 4px 12px;
  background: var(--secondary);
  border-radius: 20px;
  font-size: 12px;
  color: var(--text-gray);
}

/* ===== 案例展示 ===== */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.case-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--transition);
}

.case-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px var(--shadow);
}

.case-image {
  height: 180px;
  background: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  color: var(--primary-light);
}

.case-info {
  padding: 24px;
}

.case-info h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-dark);
}

.case-info p {
  font-size: 14px;
  color: var(--text-gray);
  margin-bottom: 12px;
  line-height: 1.6;
}

.case-tags {
  display: flex;
  gap: 8px;
}

/* ===== 表单样式 ===== */
.form-container {
  max-width: 600px;
  margin: 0 auto;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
}

.form-group {
  margin-bottom: 24px;
}

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

.form-group label .required {
  color: #EF4444;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  font-family: inherit;
  transition: border-color var(--transition);
  background: var(--white);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-submit {
  margin-top: 32px;
}

.form-submit .btn {
  width: 100%;
  justify-content: center;
}

/* 表单消息 */
.form-message {
  padding: 16px;
  border-radius: var(--radius);
  margin-bottom: 24px;
  display: none;
}

.form-message.success {
  display: block;
  background: #ECFDF5;
  color: #065F46;
  border: 1px solid #A7F3D0;
}

.form-message.error {
  display: block;
  background: #FEF2F2;
  color: #991B1B;
  border: 1px solid #FECACA;
}

/* ===== 页面头部 ===== */
.page-header {
  padding: 140px 0 60px;
  background: linear-gradient(180deg, #F0F9FF 0%, var(--white) 100%);
  text-align: center;
}

.page-header h1 {
  font-size: 40px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 12px;
}

.page-header p {
  font-size: 18px;
  color: var(--text-gray);
}

/* ===== 联系信息 ===== */
.contact-info {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-bottom: 50px;
}

.contact-card {
  text-align: center;
  padding: 30px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.contact-icon {
  width: 56px;
  height: 56px;
  background: #F0F9FF;
  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-dark);
}

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

/* ===== 页脚 ===== */
.footer {
  background: var(--text-dark);
  color: var(--white);
  padding: 60px 0 30px;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand .logo {
  margin-bottom: 16px;
}

.footer-brand .logo span {
  color: var(--white);
}

.footer-brand p {
  font-size: 14px;
  color: #9CA3AF;
  line-height: 1.7;
}

.footer-links h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 14px;
  color: #9CA3AF;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--white);
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid #374151;
  text-align: center;
  font-size: 14px;
  color: #9CA3AF;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-btns {
    justify-content: center;
  }

  .features-grid,
  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px;
    gap: 16px;
    box-shadow: 0 10px 30px var(--shadow);
  }

  .nav-links.active {
    display: flex;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero-content h1 {
    font-size: 32px;
  }

  .section {
    padding: 60px 0;
  }

  .section-title h2 {
    font-size: 26px;
  }

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

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

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

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

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-brand .logo {
    justify-content: center;
  }
}