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

html, body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
  color: #2c3e50;
  background: #f8f9fa;
  line-height: 1.6;
}

/* ============ 导航栏 ============ */
.navbar {
  background: #fff;
  border-bottom: 1px solid #e8eaed;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.navbar-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.navbar-brand {
  font-size: 20px;
  font-weight: 700;
  color: #1a73e8;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.navbar-brand svg {
  width: 28px;
  height: 28px;
}

.navbar-menu {
  display: flex;
  list-style: none;
  gap: 0;
}

.navbar-menu li {
  margin: 0;
}

.navbar-menu a {
  display: block;
  padding: 20px 18px;
  color: #5f6368;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  border-bottom: 3px solid transparent;
  transition: all 0.3s ease;
}

.navbar-menu a:hover {
  color: #1a73e8;
  background: #f8f9fa;
}

.navbar-menu a.active {
  color: #1a73e8;
  border-bottom-color: #1a73e8;
}

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

/* ============ 英雄区域 ============ */
.hero {
  background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
  color: #fff;
  padding: 80px 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 80%, rgba(255,255,255,0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero p {
  font-size: 18px;
  margin-bottom: 30px;
  opacity: 0.95;
  line-height: 1.5;
}

.hero-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-block;
  white-space: nowrap;
}

.btn-primary {
  background: #fff;
  color: #1a73e8;
}

.btn-primary:hover {
  background: #f1f3f4;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-secondary {
  background: rgba(255,255,255,0.2);
  color: #fff;
  border: 1px solid rgba(255,255,255,0.4);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.3);
  border-color: rgba(255,255,255,0.6);
}

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

.btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

/* ============ 特性卡片网格 ============ */
.features {
  padding: 60px 20px;
  background: #fff;
}

.section-title {
  text-align: center;
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 50px;
  color: #1a1a1a;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.feature-card {
  padding: 30px;
  background: #f8f9fa;
  border-radius: 12px;
  text-align: center;
  transition: all 0.3s ease;
  border: 1px solid #e8eaed;
}

.feature-card:hover {
  background: #fff;
  border-color: #1a73e8;
  box-shadow: 0 8px 24px rgba(26, 115, 232, 0.12);
  transform: translateY(-4px);
}

.feature-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, #1a73e8, #0d47a1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}

.feature-icon svg {
  width: 32px;
  height: 32px;
  stroke-width: 1.5;
}

.feature-card h3 {
  font-size: 18px;
  margin-bottom: 12px;
  color: #1a1a1a;
}

.feature-card p {
  font-size: 14px;
  color: #5f6368;
  line-height: 1.6;
}

/* ============ 平台下载区 ============ */
.platforms {
  padding: 60px 20px;
  background: #f8f9fa;
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.platform-card {
  background: #fff;
  padding: 30px;
  border-radius: 12px;
  text-align: center;
  border: 1px solid #e8eaed;
  transition: all 0.3s ease;
}

.platform-card:hover {
  border-color: #1a73e8;
  box-shadow: 0 8px 24px rgba(26, 115, 232, 0.12);
}

.platform-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: #f1f3f4;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.platform-icon svg {
  width: 32px;
  height: 32px;
  stroke: #1a73e8;
  fill: none;
  stroke-width: 1.5;
}

.platform-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: #1a1a1a;
}

.platform-card p {
  font-size: 13px;
  color: #5f6368;
  margin-bottom: 16px;
}

.platform-card .btn {
  width: 100%;
  padding: 10px 16px;
  font-size: 14px;
}

/* ============ 对比表格 ============ */
.comparison {
  padding: 60px 20px;
  background: #fff;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 30px;
  border: 1px solid #e8eaed;
  border-radius: 8px;
  overflow: hidden;
}

.comparison-table th {
  background: #f8f9fa;
  padding: 16px;
  text-align: left;
  font-weight: 600;
  color: #1a1a1a;
  border-bottom: 1px solid #e8eaed;
}

.comparison-table td {
  padding: 14px 16px;
  border-bottom: 1px solid #e8eaed;
  color: #5f6368;
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-table .check {
  color: #34a853;
  font-weight: 600;
}

.comparison-table .cross {
  color: #ea4335;
}

/* ============ FAQ 区域 ============ */
.faq {
  padding: 60px 20px;
  background: #f8f9fa;
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: #fff;
  margin-bottom: 12px;
  border: 1px solid #e8eaed;
  border-radius: 8px;
  overflow: hidden;
}

.faq-question {
  padding: 18px 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 500;
  color: #1a1a1a;
  transition: all 0.3s ease;
  user-select: none;
}

.faq-question:hover {
  background: #f8f9fa;
}

.faq-item.open .faq-question {
  background: #f1f3f4;
}

.faq-chevron {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s ease;
  color: #1a73e8;
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
  color: #5f6368;
  font-size: 14px;
  line-height: 1.6;
}

.faq-item.open .faq-answer {
  padding: 16px 24px;
  max-height: 500px;
}

/* ============ 用户评价 ============ */
.testimonials {
  padding: 60px 20px;
  background: #fff;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.testimonial-card {
  padding: 24px;
  background: #f8f9fa;
  border-radius: 12px;
  border-left: 4px solid #1a73e8;
}

.testimonial-stars {
  color: #fbbc04;
  font-size: 14px;
  margin-bottom: 12px;
}

.testimonial-text {
  font-size: 14px;
  color: #5f6368;
  margin-bottom: 16px;
  line-height: 1.6;
  font-style: italic;
}

.testimonial-author {
  font-weight: 600;
  color: #1a1a1a;
  font-size: 14px;
}

/* ============ 统计数据 ============ */
.stats {
  padding: 40px 20px;
  background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
  color: #fff;
  text-align: center;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  max-width: 1000px;
  margin: 0 auto;
}

.stat-item h3 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 8px;
}

.stat-item p {
  font-size: 14px;
  opacity: 0.9;
}

/* ============ CTA 横幅 ============ */
.cta-banner {
  padding: 50px 20px;
  background: linear-gradient(135deg, #34a853 0%, #0d652d 100%);
  color: #fff;
  text-align: center;
}

.cta-banner h2 {
  font-size: 28px;
  margin-bottom: 16px;
}

.cta-banner p {
  font-size: 16px;
  margin-bottom: 24px;
  opacity: 0.95;
}

.cta-banner .btn {
  background: #fff;
  color: #0d652d;
  font-weight: 600;
}

.cta-banner .btn:hover {
  background: #f1f3f4;
}

/* ============ 页脚 ============ */
.footer {
  background: #2c3e50;
  color: #ecf0f1;
  padding: 40px 20px;
  text-align: center;
  font-size: 13px;
  line-height: 1.8;
}

.footer p {
  margin: 8px 0;
}

.footer a {
  color: #3498db;
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

/* ============ 动画 ============ */
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

/* ============ 响应式设计 ============ */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 32px;
  }

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

  .hero-buttons {
    flex-direction: column;
  }

  .hero-buttons .btn {
    width: 100%;
  }

  .section-title {
    font-size: 24px;
  }

  .navbar-menu {
    gap: 0;
  }

  .navbar-menu a {
    padding: 16px 12px;
    font-size: 13px;
  }

  .comparison-table {
    font-size: 13px;
  }

  .comparison-table th,
  .comparison-table td {
    padding: 12px;
  }

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

  .cta-banner h2 {
    font-size: 22px;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 50px 20px;
  }

  .hero h1 {
    font-size: 24px;
  }

  .hero p {
    font-size: 14px;
  }

  .section-title {
    font-size: 20px;
    margin-bottom: 30px;
  }

  .features-grid,
  .platforms-grid,
  .testimonials-grid {
    grid-template-columns: 1fr;
  }

  .navbar-container {
    height: 56px;
  }

  .navbar-brand {
    font-size: 16px;
  }

  .navbar-menu a {
    padding: 14px 10px;
    font-size: 12px;
  }

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