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

:root {
  --primary: #2563EB;
  --primary-dark: #0B3D91;
  --primary-light: #3B82F6;
  --accent: #14B8A6;
  --text: #0F172A;
  --text-light: #64748B;
  --bg: #FFFFFF;
  --bg-gray: #F8FAFC;
  --border: #E2E8F0;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  z-index: 1000;
}

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

.nav-brand {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-dark);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 30px;
}

.nav-menu a {
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  transition: color 0.3s;
}

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

.nav-toggle {
  display: none;
  font-size: 24px;
  cursor: pointer;
}

/* Banner */
.banner {
  height: 100vh;
  min-height: 600px;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: white;
  position: relative;
  overflow: hidden;
}

.banner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.banner-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 20px;
}

.banner h1 {
  font-size: 64px;
  font-weight: 800;
  margin-bottom: 20px;
  letter-spacing: 4px;
}

.banner p {
  font-size: 22px;
  margin-bottom: 40px;
  opacity: 0.9;
}

.banner-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
}

.btn {
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s;
  border: none;
  display: inline-block;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  color: white;
  border: 2px solid white;
}

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

.btn-full {
  width: 100%;
}

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

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

.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 15px;
  color: var(--text);
}

.section-subtitle {
  font-size: 18px;
  text-align: center;
  color: var(--text-light);
  margin-bottom: 60px;
}

/* 产品中心 */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

.product-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  border: 1px solid var(--border);
}

.product-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.product-image {
  width: 100%;
  height: 220px;
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 64px;
}

.product-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.product-info {
  padding: 25px;
}

.product-info h3 {
  font-size: 22px;
  margin-bottom: 12px;
  color: var(--text);
}

.product-info p {
  color: var(--text-light);
  font-size: 15px;
  line-height: 1.7;
}

/* 技术参数 */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 25px;
  margin-bottom: 60px;
}

.tech-card {
  background: white;
  padding: 35px 25px;
  border-radius: 12px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all 0.3s;
}

.tech-card:hover {
  transform: translateY(-5px);
}

.tech-icon {
  font-size: 48px;
  margin-bottom: 20px;
}

.tech-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
  color: var(--primary-dark);
}

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

.standards-list {
  background: white;
  padding: 40px;
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.standards-list h3 {
  font-size: 24px;
  margin-bottom: 25px;
  color: var(--primary-dark);
}

.standards-list ul {
  list-style: none;
}

.standards-list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-size: 15px;
}

.standards-list li:last-child {
  border-bottom: none;
}

.standards-list li::before {
  content: '✓ ';
  color: var(--accent);
  font-weight: bold;
  margin-right: 8px;
}

/* 应用领域 */
.applications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 25px;
}

.application-card {
  background: white;
  padding: 35px 25px;
  border-radius: 12px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  border-top: 4px solid var(--primary);
}

.application-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.application-icon {
  font-size: 48px;
  margin-bottom: 18px;
}

.application-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
  color: var(--text);
}

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

/* 关于我们 */
.about-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

.about-text h3 {
  font-size: 28px;
  margin-bottom: 20px;
  color: var(--primary-dark);
}

.about-text p {
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-light);
  margin-bottom: 30px;
}

.about-features {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}

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

.feature-num {
  display: block;
  font-size: 42px;
  font-weight: 800;
  color: var(--primary);
}

.feature-text {
  display: block;
  font-size: 14px;
  color: var(--text-light);
  margin-top: 5px;
}

/* 联系我们 */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.contact-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.contact-icon {
  font-size: 32px;
  min-width: 50px;
}

.contact-item h4 {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--text);
}

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

.contact-form {
  background: var(--bg-gray);
  padding: 40px;
  border-radius: 12px;
}

.contact-form h3 {
  font-size: 24px;
  margin-bottom: 25px;
  color: var(--primary-dark);
}

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

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 14px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  transition: border-color 0.3s;
  background: white;
}

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

.form-group textarea {
  resize: vertical;
}

/* 页脚 */
.footer {
  background: var(--text);
  color: white;
  padding: 60px 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  font-size: 24px;
  margin-bottom: 12px;
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

.footer-links h4,
.footer-contact h4 {
  font-size: 18px;
  margin-bottom: 20px;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s;
}

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

.footer-contact p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
  margin-bottom: 10px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
  color: rgba(255, 255, 255, 0.5);
  font-size: 13px;
}

/* 响应式 */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 20px;
    box-shadow: var(--shadow);
  }

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

  .nav-toggle {
    display: block;
  }

  .banner h1 {
    font-size: 40px;
  }

  .banner p {
    font-size: 16px;
  }

  .banner-buttons {
    flex-direction: column;
    align-items: center;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 28px;
  }

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

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

  .about-features {
    justify-content: center;
  }
}

/* 后台管理样式 */
.admin-layout {
  display: flex;
  min-height: 100vh;
}

.admin-sidebar {
  width: 250px;
  background: var(--text);
  color: white;
  padding: 20px 0;
}

.admin-sidebar h2 {
  padding: 0 20px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  font-size: 20px;
}

.admin-menu {
  list-style: none;
  margin-top: 20px;
}

.admin-menu li a {
  display: block;
  padding: 12px 20px;
  color: rgba(255,255,255,0.8);
  text-decoration: none;
  transition: all 0.3s;
}

.admin-menu li a:hover,
.admin-menu li a.active {
  background: var(--primary);
  color: white;
}

.admin-main {
  flex: 1;
  background: var(--bg-gray);
  padding: 30px;
}

.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.admin-header h1 {
  font-size: 28px;
}

.admin-card {
  background: white;
  border-radius: 12px;
  padding: 25px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.stat-card {
  background: white;
  padding: 25px;
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.stat-card h3 {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 10px;
}

.stat-card .stat-num {
  font-size: 36px;
  font-weight: 700;
  color: var(--primary);
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
}

.admin-table th,
.admin-table td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.admin-table th {
  background: var(--bg-gray);
  font-weight: 600;
  color: var(--text);
}

.admin-table tr:hover {
  background: var(--bg-gray);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: 6px;
}

.btn-danger {
  background: #EF4444;
  color: white;
}

.btn-success {
  background: #10B981;
  color: white;
}

.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
}

.login-box {
  background: white;
  padding: 40px;
  border-radius: 12px;
  width: 100%;
  max-width: 400px;
  box-shadow: var(--shadow-lg);
}

.login-box h2 {
  text-align: center;
  margin-bottom: 30px;
  color: var(--primary-dark);
}