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

body {
  font-family: 'Roboto', sans-serif;
  color: #333;
  line-height: 1.6;
  background-color: #fff;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

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

img {
  max-width: 100%;
  border-radius: 8px;
}

/* 按钮 */
.btn {
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.btn-large {
  padding: 14px 32px;
  font-size: 16px;
}

.btn-primary {
  background-color: #2563eb;
  color: #fff;
}

.btn-primary:hover {
  background-color: #1d4ed8;
}

.btn-outline {
  background: transparent;
  color: #2563eb;
  border: 1px solid #2563eb;
}

.btn-outline:hover {
  background-color: #eff6ff;
}

/* 导航 */
.header {
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  padding: 16px 0;
  position: sticky;
  top: 0;
  background: #fff;
  z-index: 999;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo img {
  height: 40px;
  border-radius: 0;
}

.nav {
  display: flex;
  gap: 30px;
}

.nav-link {
  font-size: 15px;
  color: #555;
  font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
  color: #2563eb;
}

.header-actions {
  display: flex;
  gap: 14px;
}

/* 横幅 */
.hero {
  padding: 80px 0;
  background: linear-gradient(180deg, #f8fafc 0%, #eff6ff 100%);
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 40px;
}

.hero-content {
  flex: 1;
}

.hero-content h1 {
  font-size: 42px;
  line-height: 1.2;
  margin-bottom: 20px;
  color: #1e293b;
}

.hero-content p {
  font-size: 18px;
  color: #64748b;
  margin-bottom: 30px;
}

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

.hero-image {
  flex: 1;
  text-align: center;
}

/* 模块标题 */
.section-title {
  text-align: center;
  margin-bottom: 50px;
}

.section-title h2 {
  font-size: 32px;
  margin-bottom: 10px;
  color: #1e293b;
}

.section-title p {
  font-size: 16px;
  color: #64748b;
}

/* 功能卡片 */
.features {
  padding: 80px 0;
}

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

.feature-card {
  background: #fff;
  padding: 30px;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  transition: transform 0.2s;
}

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

.feature-icon {
  width: 64px;
  height: 64px;
  background-color: #dbeafe;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px auto;
}

.feature-icon .material-icons {
  font-size: 32px;
  color: #2563eb;
}

.feature-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
  color: #1e293b;
}

.feature-card p {
  font-size: 15px;
  color: #64748b;
}

.feature-card img {
  margin-bottom: 18px;
  height: 180px;
  object-fit: cover;
  width: 100%;
}

/* 底部 */
.footer {
  padding: 50px 0;
  background: #f8fafc;
  border-top: 1px solid #e2e8f0;
  text-align: center;
}

.footer-logo img {
  height: 40px;
  margin-bottom: 20px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
}

.footer-link {
  font-size: 14px;
  color: #64748b;
}

.footer-link:hover {
  color: #2563eb;
}

.footer-copyright {
  font-size: 13px;
  color: #94a3b8;
}

/* 响应式 */
@media (max-width: 900px) {
  .hero-inner {
    flex-direction: column;
    text-align: center;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .nav {
    display: none;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .hero-content h1 {
    font-size: 32px;
  }
}