/* CSS变量定义 - 支持主题切换 */
:root {
  /* 颜色变量 */
  --primary-color: #2563eb;
  --secondary-color: #7c3aed;
  --accent-color: #f59e0b;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #3b82f6;
  
  /* 背景色 */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  
  /* 文字颜色 */
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-tertiary: #94a3b8;
  
  /* 边框颜色 */
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  
  /* 卡片背景 */
  --card-bg: #ffffff;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  /* 渐变背景 */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  
  /* 间距 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* 字体 */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* 过渡 */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
}

/* 暗色主题 */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-tertiary: #94a3b8;
  
  --border-color: #334155;
  --border-hover: #475569;
  
  --card-bg: #1e293b;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* 头部导航 */
.header {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background-color: rgba(var(--bg-primary), 0.8);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo h1 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--primary-color);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

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

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width var(--transition-fast);
}

.nav-links a:hover::after {
  width: 100%;
}

/* 主题切换按钮 */
.theme-toggle {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border: 2px solid var(--border-color);
  border-radius: 50px;
  padding: 8px;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 56px;
  height: 56px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
  border-color: var(--primary-color);
  transform: scale(1.08) rotate(5deg);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
}

.theme-toggle:active {
  transform: scale(0.92) rotate(-2deg);
}

.theme-toggle svg {
  width: 28px;
  height: 28px;
  stroke: var(--text-secondary);
  transition: all var(--transition-normal);
  position: absolute;
}

.theme-toggle:hover svg {
  stroke: var(--primary-color);
}

[data-theme="dark"] .sun-icon {
  opacity: 0;
  transform: rotate(180deg) scale(0);
}

[data-theme="light"] .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

[data-theme="light"] .moon-icon {
  opacity: 0;
  transform: rotate(-180deg) scale(0);
}

/* 英雄区域 */
.hero {
  padding: var(--spacing-2xl) 0;
  background: var(--gradient-primary);
  color: white;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, rgba(255,255,255,0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.hero-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  box-shadow: var(--card-shadow);
  transition: all var(--transition-normal);
}

.hero-icon:hover {
  transform: scale(1.1);
  box-shadow: var(--card-shadow-hover);
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-lg);
  opacity: 0.9;
}

.version-info {
  background: rgba(255, 255, 255, 0.2);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-lg);
  display: inline-block;
  margin-bottom: var(--spacing-lg);
  backdrop-filter: blur(10px);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image svg {
  max-width: 100%;
  height: auto;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.2));
}

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

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

.btn-primary:hover {
  background-color: #1d4ed8;
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(37, 99, 235, 0.3);
}

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

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

.btn-large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-lg);
}

/* 功能特点 */
.features {
  padding: var(--spacing-2xl) 0;
  background-color: var(--bg-secondary);
}

.section-title {
  text-align: center;
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-2xl);
  color: var(--text-primary);
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.feature-card {
  background-color: var(--card-bg);
  padding: var(--spacing-xl);
  border-radius: var(--radius-xl);
  box-shadow: var(--card-shadow);
  transition: all var(--transition-normal);
  border: 1px solid var(--border-color);
}

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

.feature-icon {
  margin-bottom: var(--spacing-md);
}

.feature-card h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

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

/* 下载区域 */
.download {
  padding: var(--spacing-2xl) 0;
  background-color: var(--bg-primary);
}

.download-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
}

.download-info h3 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  color: var(--text-primary);
}

.download-features {
  margin-bottom: var(--spacing-xl);
}

.feature-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

.download-button {
  margin-bottom: var(--spacing-md);
}

.download-size {
  color: var(--text-tertiary);
  font-size: var(--font-size-sm);
}

.download-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.download-image svg {
  max-width: 100%;
  height: auto;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.1));
}

/* 关于我们 */
.about {
  padding: var(--spacing-2xl) 0;
  background-color: var(--bg-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
}

.about-text h3 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  color: var(--text-primary);
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.about-links {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.about-links a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border: 1px solid var(--primary-color);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.about-links a:hover {
  background-color: var(--primary-color);
  color: white;
}

.about-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.about-image svg {
  max-width: 100%;
  height: auto;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.1));
}

/* 页脚 */
.footer {
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

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

.footer-section li {
  margin-bottom: var(--spacing-xs);
}

.footer-section a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  color: var(--text-tertiary);
  font-size: var(--font-size-sm);
}

.footer-bottom p {
  margin-bottom: var(--spacing-xs);
}

.footer-bottom a {
  color: inherit;
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

.footer-bottom a:hover {
  opacity: 1;
  text-decoration: underline;
}

/* 安全警告 */
.security-warning {
  position: fixed;
  top: 20px;
  right: 20px;
  background-color: var(--warning-color);
  color: white;
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--card-shadow);
  z-index: 1000;
  max-width: 300px;
}

.warning-content {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
}

.warning-content button {
  background: none;
  border: none;
  color: white;
  font-size: var(--font-size-lg);
  cursor: pointer;
  padding: 0;
  margin-left: auto;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .nav-links {
    gap: var(--spacing-md);
  }
  
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-lg);
  }
  
  .hero-title {
    font-size: var(--font-size-3xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-lg);
  }
  
  .hero-buttons {
    justify-content: center;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .download-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .about-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .about-links {
    justify-content: center;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .hero-buttons {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: var(--spacing-xl) 0;
  }
  
  .features,
  .download,
  .about {
    padding: var(--spacing-xl) 0;
  }
  
  .section-title {
    font-size: var(--font-size-2xl);
  }
  
  .feature-card {
    padding: var(--spacing-lg);
  }
  
  .download-info h3,
  .about-text h3 {
    font-size: var(--font-size-2xl);
  }
}

/* 动画效果 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

@keyframes bounce {
  0%, 20%, 53%, 80%, 100% {
    transform: translate3d(0, 0, 0);
  }
  40%, 43% {
    transform: translate3d(0, -8px, 0);
  }
  70% {
    transform: translate3d(0, -4px, 0);
  }
  90% {
    transform: translate3d(0, -2px, 0);
  }
}

/* 滚动动画 */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-normal);
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* 加载动画 */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255,255,255,.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 焦点样式 */
button:focus,
a:focus,
input:focus,
textarea:focus,
select:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
  :root {
    --text-primary: #000000;
    --text-secondary: #333333;
    --bg-primary: #ffffff;
    --border-color: #000000;
  }
  
  [data-theme="dark"] {
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --bg-primary: #000000;
    --border-color: #ffffff;
  }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}