/* CSS 变量 */
:root {
  --chrome-blue: #4285F4;
  --chrome-green: #34A853;
  --chrome-yellow: #FBBC05;
  --chrome-red: #EA4335;
  --primary-color: #4285F4;
  --secondary-color: #34A853;
  --accent-color: #FBBC05;
  --text-color: #202124;
  --text-secondary: #5f6368;
  --background-color: #ffffff;
  --background-secondary: #f8f9fa;
  --border-color: #e0e0e0;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
  --border-radius: 8px;
  --transition: all 0.3s ease;
  --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* 深色模式 */
@media (prefers-color-scheme: dark) {
  :root {
    --text-color: #e8eaed;
    --text-secondary: #9aa0a6;
    --background-color: #202124;
    --background-secondary: #303134;
    --border-color: #5f6368;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
  }
}

/* 基础样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-color);
  transition: var(--transition);
}

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

/* 头部 */
.header {
  background-color: var(--background-color);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: var(--transition);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
}

.nav-logo {
  flex-shrink: 0;
}

.nav-logo svg {
  height: 30px;
  color: var(--text-color);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 30px;
}

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

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
}

.nav-toggle span {
  width: 25px;
  height: 2px;
  background-color: var(--text-color);
  transition: var(--transition);
}

/* 按钮 */
.btn-primary {
  display: inline-block;
  padding: 12px 24px;
  background-color: var(--primary-color);
  color: white;
  text-decoration: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  background-color: #3367d6;
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  color: white;
}

.btn-secondary {
  display: inline-block;
  padding: 12px 24px;
  background-color: transparent;
  color: var(--text-color);
  text-decoration: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

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

/* 英雄区域 */
.hero {
  padding: 100px 0;
  background: linear-gradient(135deg, var(--background-secondary) 0%, var(--background-color) 100%);
  transition: var(--transition);
}

.hero-content {
  max-width: 500px;
  margin-bottom: 50px;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 20px;
  line-height: 1.2;
  background: linear-gradient(135deg, var(--chrome-blue), var(--chrome-green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 30px;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.hero-image {
  max-width: 600px;
  margin: 0 auto;
}

.hero-image svg {
  width: 100%;
  height: auto;
}

/* 功能区域 */
.features {
  padding: 100px 0;
}

.features h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.section-description {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 50px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-top: 50px;
}

.feature-card {
  background-color: var(--background-color);
  border-radius: var(--border-radius);
  padding: 40px 30px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

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

.feature-icon {
  margin-bottom: 20px;
  display: inline-block;
}

.feature-card h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 15px;
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 性能区域 */
.performance {
  padding: 100px 0;
  background-color: var(--background-secondary);
  transition: var(--transition);
}

.performance h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.performance-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-top: 50px;
}

.stat-item {
  text-align: center;
  padding: 40px 20px;
  background-color: var(--background-color);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.stat-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 10px;
  background: linear-gradient(135deg, var(--chrome-blue), var(--chrome-green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  color: var(--text-secondary);
  font-weight: 500;
}

/* 安全区域 */
.security {
  padding: 100px 0;
}

.security h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.security-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
  margin-top: 50px;
}

.security-item {
  text-align: center;
  padding: 40px 30px;
  background-color: var(--background-color);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.security-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.security-item h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 15px;
}

.security-item p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 下载 CTA */
.download-cta {
  padding: 100px 0;
  background: linear-gradient(135deg, var(--chrome-blue), var(--chrome-green));
  color: white;
  text-align: center;
}

.download-cta h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 15px;
}

.download-cta p {
  font-size: 1.1rem;
  margin-bottom: 30px;
  opacity: 0.9;
}

.download-cta .btn-primary {
  background-color: white;
  color: var(--chrome-blue);
  font-weight: 600;
}

.download-cta .btn-primary:hover {
  background-color: var(--background-secondary);
  transform: translateY(-2px);
}

/* 支持区域 */
.support {
  padding: 100px 0;
  background-color: var(--background-secondary);
  transition: var(--transition);
}

.support h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.support-links {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-top: 50px;
  flex-wrap: wrap;
}

.support-link {
  display: inline-block;
  padding: 15px 30px;
  background-color: var(--background-color);
  color: var(--text-color);
  text-decoration: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.support-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  color: var(--primary-color);
}

/* 下载页面样式 */
.download-hero {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--chrome-blue), var(--chrome-green));
  color: white;
  text-align: center;
}

.download-hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 15px;
}

.download-hero p {
  font-size: 1.1rem;
  opacity: 0.9;
}

.download-options {
  padding: 100px 0;
}

.download-options h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.platforms {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-top: 50px;
}

.platform-card {
  background-color: var(--background-color);
  border-radius: var(--border-radius);
  padding: 40px 30px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

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

.platform-icon {
  margin-bottom: 20px;
  display: inline-block;
}

.platform-card h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.platform-card p {
  color: var(--text-secondary);
  margin-bottom: 20px;
}

/* 系统要求 */
.system-requirements {
  padding: 100px 0;
  background-color: var(--background-secondary);
  transition: var(--transition);
}

.system-requirements h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.requirements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-top: 50px;
}

.requirement-item {
  background-color: var(--background-color);
  border-radius: var(--border-radius);
  padding: 40px 30px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.requirement-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.requirement-item h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.requirement-item ul {
  list-style: none;
}

.requirement-item li {
  color: var(--text-secondary);
  margin-bottom: 10px;
  position: relative;
  padding-left: 20px;
}

.requirement-item li:before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--chrome-green);
  font-weight: bold;
}

/* FAQ */
.faq {
  padding: 100px 0;
}

.faq h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
  text-align: center;
}

.faq-items {
  max-width: 800px;
  margin: 50px auto 0;
}

.faq-item {
  margin-bottom: 20px;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  background-color: var(--background-color);
  transition: var(--transition);
}

.faq-item:hover {
  box-shadow: var(--shadow-hover);
}

.faq-question {
  padding: 20px 30px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  background-color: var(--background-secondary);
  transition: var(--transition);
  margin: 0;
  border: none;
  width: 100%;
  text-align: left;
  position: relative;
}

.faq-question:hover {
  background-color: var(--border-color);
}

.faq-question:after {
  content: "+";
  position: absolute;
  right: 30px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.5rem;
  font-weight: bold;
  transition: var(--transition);
}

.faq-question.active:after {
  content: "-";
}

.faq-answer {
  padding: 0 30px;
  max-height: 0;
  overflow: hidden;
  transition: var(--transition);
}

.faq-answer.active {
  padding: 20px 30px;
  max-height: 200px;
}

.faq-answer p {
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
}

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

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.footer-logo {
  margin-bottom: 30px;
}

.footer-logo svg {
  height: 40px;
  color: var(--text-color);
}

.footer-links {
  display: flex;
  gap: 30px;
  margin-bottom: 30px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.9rem;
}

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

.footer-copyright {
  font-size: 0.9rem;
  opacity: 0.8;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background-color: var(--background-color);
    flex-direction: column;
    align-items: center;
    padding: 30px 0;
    gap: 20px;
    box-shadow: var(--shadow);
    transform: translateY(-150%);
    transition: var(--transition);
    z-index: 999;
  }

  .nav-links.active {
    transform: translateY(0);
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: 60px 0;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-content {
    max-width: 100%;
    text-align: center;
  }

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

  .features,
  .performance,
  .security,
  .support,
  .download-cta,
  .download-options,
  .system-requirements,
  .faq {
    padding: 60px 0;
  }

  .features h2,
  .performance h2,
  .security h2,
  .support h2,
  .download-cta h2,
  .download-options h2,
  .system-requirements h2,
  .faq h2 {
    font-size: 1.8rem;
  }

  .support-links {
    flex-direction: column;
    align-items: center;
  }

  .support-link {
    width: 200px;
    text-align: center;
  }

  .footer-links {
    flex-direction: column;
    gap: 15px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.8rem;
  }

  .btn-primary,
  .btn-secondary {
    padding: 10px 20px;
    font-size: 0.9rem;
  }

  .features h2,
  .performance h2,
  .security h2,
  .support h2,
  .download-cta h2,
  .download-options h2,
  .system-requirements h2,
  .faq h2 {
    font-size: 1.5rem;
  }

  .feature-card,
  .platform-card,
  .requirement-item {
    padding: 30px 20px;
  }

  .stat-item {
    padding: 30px 15px;
  }

  .stat-number {
    font-size: 2rem;
  }
}

/* 动画效果 */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

.fade-in {
  animation: fadeIn 0.8s ease forwards;
}

.pulse {
  animation: pulse 2s infinite;
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--background-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* 选择文本样式 */
::selection {
  background-color: var(--chrome-blue);
  color: white;
}

/* 焦点样式 */
:focus {
  outline: 2px solid var(--chrome-blue);
  outline-offset: 2px;
}

/* 无障碍支持 */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000000;
    --text-secondary: #000000;
  }
}