/* Google Chrome 风格现代浏览器官网 CSS */
:root {
  --primary: #4285f4;
  --primary-dark: #3367d6;
  --text: #202124;
  --text-light: #5f6368;
  --bg: #ffffff;
  --card-bg: #f8f9fa;
  --border: #dadce0;
}

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

body {
  font-family: "Google Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
}

/* 导航栏 */
.navbar {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
  padding: 0 5%;
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  font-size: 22px;
}

.logo-svg {
  width: 32px;
  height: 32px;
}

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

.nav-menu a {
  color: var(--text-light);
  text-decoration: none;
  font-weight: 500;
  padding: 8px 0;
  position: relative;
  transition: color 0.3s;
}

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

.nav-menu a.active {
  color: var(--primary);
  font-weight: 600;
}

.nav-menu a.active:after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--primary);
  border-radius: 3px;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn {
  padding: 10px 24px;
  border-radius: 50px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  border: none;
  font-size: 15px;
}

.btn-primary {
  background: var(--primary);
  color: white;
  box-shadow: 0 1px 3px rgba(66, 133, 244, 0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(66, 133, 244, 0.4);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

/* 英雄区 */
.hero {
  background: linear-gradient(135deg, #f0f7ff 0%, #e6f0ff 100%);
  padding: 140px 5% 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(66,133,244,0.08) 0%, transparent 70%);
  z-index: 0;
}

.hero-content {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-text h1 {
  font-size: 56px;
  line-height: 1.1;
  margin-bottom: 24px;
  color: #1a73e8;
}

.hero-text p {
  font-size: 22px;
  color: var(--text-light);
  margin-bottom: 40px;
  max-width: 480px;
}

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

/* 特性区 */
.features {
  padding: 100px 5%;
  background: white;
}

.section-title {
  text-align: center;
  font-size: 38px;
  margin-bottom: 20px;
  color: var(--text);
}

.section-subtitle {
  text-align: center;
  font-size: 20px;
  color: var(--text-light);
  max-width: 680px;
  margin: 0 auto 60px;
}

.features-grid {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 32px;
}

.feature-card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 40px 32px;
  border: 1px solid var(--border);
  transition: all 0.4s cubic-bezier(0.4, 0.0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-12px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.08);
  border-color: #4285f4;
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: #e8f0fe;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: #4285f4;
}

.feature-card h3 {
  font-size: 24px;
  margin-bottom: 16px;
}

.feature-card p {
  color: var(--text-light);
  font-size: 16px;
}

/* 下载区 */
.download-section {
  background: linear-gradient(135deg, #f8f9fa 0%, #f1f3f4 100%);
  padding: 100px 5%;
}

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

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 50px;
}

.download-card {
  background: white;
  border-radius: 20px;
  padding: 40px;
  text-align: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06);
  transition: all 0.3s;
  border: 1px solid #e0e0e0;
}

.download-card:hover {
  transform: scale(1.03);
  box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.15);
}

.platform-icon {
  width: 78px;
  height: 78px;
  margin: 0 auto 24px;
}

.download-card h3 {
  font-size: 26px;
  margin-bottom: 12px;
}

.download-card .desc {
  color: var(--text-light);
  margin-bottom: 32px;
  min-height: 48px;
}

.download-btn {
  width: 100%;
  padding: 16px;
  font-size: 18px;
  font-weight: 600;
}

/* 用户评价 */
.testimonials {
  padding: 100px 5%;
  background: white;
}

.testimonial-grid {
  max-width: 1280px;
  margin: 60px auto 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 30px;
}

.testimonial {
  background: #f8f9fa;
  padding: 40px;
  border-radius: 18px;
  border-left: 5px solid var(--primary);
}

.testimonial p {
  font-size: 17px;
  line-height: 1.7;
  margin-bottom: 24px;
  font-style: italic;
  color: #444;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 16px;
}

.testimonial-author .avatar {
  width: 48px;
  height: 48px;
  background: #4285f4;
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 18px;
}

/* FAQ */
.faq {
  padding: 100px 5%;
  background: #f8f9fa;
}

.faq-container {
  max-width: 820px;
  margin: 0 auto;
}

.faq-item {
  background: white;
  margin-bottom: 16px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.faq-question {
  padding: 24px 32px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 500;
  font-size: 18px;
  transition: background 0.2s;
}

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

.faq-answer {
  padding: 0 32px 28px;
  color: var(--text-light);
  font-size: 16px;
  line-height: 1.75;
  display: none;
}

.faq-item.active .faq-answer {
  display: block;
}

/* SEO 页面专用 */
.seo-content {
  max-width: 860px;
  margin: 0 auto;
  padding: 60px 5% 120px;
}

.seo-content h1, .seo-content h2 {
  color: var(--text);
  margin-bottom: 20px;
}

.seo-content p {
  font-size: 18px;
  line-height: 1.8;
  margin-bottom: 28px;
  color: #444;
}

/* 页脚 */
.footer {
  background: #202124;
  color: #dadce0;
  padding: 80px 5% 40px;
  font-size: 14px;
}

.footer-content {
  max-width: 1280px;
  margin: 0 auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 60px;
}

.footer-col h3 {
  color: white;
  margin-bottom: 20px;
  font-size: 15px;
  letter-spacing: 0.5px;
}

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

.footer-col ul li {
  margin-bottom: 12px;
}

.footer-col a {
  color: #dadce0;
  text-decoration: none;
  transition: color .2s;
}

.footer-col a:hover {
  color: #8ab4f8;
}

.footer-notice {
  border-top: 1px solid #3c4043;
  padding-top: 30px;
  text-align: center;
  font-size: 13px;
  line-height: 1.7;
  color: #9aa0a6;
}

.footer-notice strong {
  color: #8ab4f8;
}

/* 响应式 */
@media (max-width: 768px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }
  
  .hero-text h1 {
    font-size: 42px;
  }
  
  .nav-menu {
    display: none;
  }
  
  .features-grid, .download-grid {
    grid-template-columns: 1fr;
  }
}

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

.loading-spinner {
  animation: spin 1s linear infinite;
}

/* 徽章 */
.badge {
  display: inline-block;
  background: #34a853;
  color: white;
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 20px;
  margin-left: 10px;
  font-weight: 500;
}