/* ========================================
   APP产品宣传网站 - 主样式文件
   设计风格：苹果简约风格
   ======================================== */

/* CSS变量定义 - 方便主题统一管理 */
:root {
  /* 颜色系统 */
  --primary-blue: #007AFF;
  --primary-blue-hover: #0056D6;
  --text-primary: #1D1D1F;
  --text-secondary: #86868B;
  --text-tertiary: #A1A1A6;
  --background-primary: #FFFFFF;
  --background-secondary: #F5F5F7;
  --background-tertiary: #FBFBFD;
  --border-color: #E5E5E7;
  --shadow-light: rgba(0, 0, 0, 0.08);
  --shadow-medium: rgba(0, 0, 0, 0.12);
  
  /* 字体系统 */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 32px;
  --font-size-4xl: 40px;
  --font-size-5xl: 48px;
  
  /* 间距系统 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --spacing-4xl: 80px;
  
  /* 圆角系统 */
  --border-radius-sm: 6px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 20px;
  
  /* 过渡动画 */
  --transition-fast: 0.15s ease-out;
  --transition-medium: 0.25s ease-out;
  --transition-slow: 0.35s ease-out;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   导航栏样式
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: all var(--transition-medium);
}

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

.navbar-brand {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.navbar-brand:hover {
  color: var(--primary-blue);
}

.navbar-nav {
  display: flex;
  list-style: none;
  gap: var(--spacing-xl);
}

.navbar-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 400;
  font-size: var(--font-size-base);
  transition: color var(--transition-fast);
  position: relative;
}

.navbar-nav a:hover,
.navbar-nav a.active {
  color: var(--primary-blue);
}

.navbar-nav a::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--primary-blue);
  transform: scaleX(0);
  transition: transform var(--transition-fast);
}

.navbar-nav a:hover::after,
.navbar-nav a.active::after {
  transform: scaleX(1);
}

/* ========================================
   主要内容区域
   ======================================== */
.main-content {
  margin-top: 64px; /* 导航栏高度 */
  min-height: calc(100vh - 64px);
}

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

.container-narrow {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ========================================
   英雄区域样式
   ======================================== */
.hero-section {
  background: linear-gradient(135deg, var(--background-primary) 0%, var(--background-secondary) 100%);
  padding: var(--spacing-4xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(0, 122, 255, 0.05) 0%, transparent 70%);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-2xl);
  line-height: 1.4;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ========================================
   按钮样式
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  border: none;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

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

.btn-primary:hover {
  background-color: var(--primary-blue-hover);
  transform: translateY(-1px);
  box-shadow: 0 8px 25px rgba(0, 122, 255, 0.3);
}

.btn-secondary {
  background-color: var(--background-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--background-primary);
  transform: translateY(-1px);
  box-shadow: 0 8px 25px var(--shadow-light);
}

/* ========================================
   卡片样式
   ======================================== */
.card {
  background-color: var(--background-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  box-shadow: 0 2px 12px var(--shadow-light);
  transition: all var(--transition-medium);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px var(--shadow-medium);
}

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

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

/* ========================================
   网格布局
   ======================================== */
.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* ========================================
   APP展示区域样式
   ======================================== */
.apps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-2xl);
  margin-top: var(--spacing-3xl);
}

.app-card {
  background: white;
  border-radius: 24px;
  padding: var(--spacing-2xl);
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
  border: 1px solid rgba(0,0,0,0.05);
  position: relative;
  overflow: hidden;
}

.app-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.15);
  border-color: rgba(0,0,0,0.1);
}

.app-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #007AFF, #34C759, #FF9500, #5856D6);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.app-card:hover::before {
  opacity: 1;
}

.app-icon-container {
  display: flex;
  justify-content: center;
  margin-bottom: var(--spacing-xl);
}

.app-icon-container > div {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
  transition: transform 0.3s ease;
}

.app-card:hover .app-icon-container > div {
  transform: scale(1.05);
}

.app-icon-container img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.app-features {
  margin-bottom: var(--spacing-lg);
}

.app-features > div {
  display: flex;
  align-items: center;
  margin-bottom: var(--spacing-sm);
  opacity: 0.8;
  transition: opacity 0.3s ease;
}

.app-card:hover .app-features > div {
  opacity: 1;
}

.app-features svg {
  margin-right: var(--spacing-sm);
  transition: transform 0.3s ease;
}

.app-card:hover .app-features svg {
  transform: translateX(2px);
}

/* APP展示区域响应式设计 */
@media (max-width: 768px) {
  .apps-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
  }
  
  .app-card {
    padding: var(--spacing-xl);
  }
  
  .app-icon-container > div {
    width: 70px;
    height: 70px;
    border-radius: 16px;
  }
}

@media (max-width: 480px) {
  .app-card {
    border-radius: 20px;
    padding: var(--spacing-lg);
  }
  
  .app-icon-container > div {
    width: 60px;
    height: 60px;
    border-radius: 14px;
  }
}

/* ========================================
   页脚样式
   ======================================== */
.footer {
  background-color: var(--background-tertiary);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-2xl) 0;
  margin-top: var(--spacing-4xl);
}

.footer-content {
  text-align: center;
  color: var(--text-tertiary);
  font-size: var(--font-size-sm);
}

/* ========================================
   工具类
   ======================================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }
.mb-2xl { margin-bottom: var(--spacing-2xl); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mt-2xl { margin-top: var(--spacing-2xl); }

.section-padding {
  padding: var(--spacing-3xl) 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}