/* ============================================
   德扑圈下载站 - Design System
   Apple + Linear + Stripe + Vercel Inspired
   ============================================ */

/* CSS Variables - Design Tokens */
:root {
  /* Colors - Deep Blue + Tech Blue */
  --color-primary: #0066FF;
  --color-primary-dark: #0044CC;
  --color-primary-light: #3B82F6;
  --color-accent: #06B6D4;
  --color-accent-light: #22D3EE;
  --color-deep: #0A1628;
  --color-deep-light: #1E293B;
  --color-deep-card: #1A2B44;
  
  /* Neutral Colors */
  --color-bg: #FAFBFC;
  --color-bg-alt: #F1F5F9;
  --color-surface: #FFFFFF;
  --color-border: #E2E8F0;
  --color-border-light: #F1F5F9;
  --color-text: #0F172A;
  --color-text-secondary: #475569;
  --color-text-tertiary: #94A3B8;
  --color-text-inverse: #F8FAFC;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #0066FF 0%, #06B6D4 100%);
  --gradient-deep: linear-gradient(135deg, #0A1628 0%, #1E3A5F 100%);
  --gradient-hero: linear-gradient(160deg, #0A1628 0%, #0D2847 40%, #0E3A6B 100%);
  --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.08) 0%, rgba(255,255,255,0.02) 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(0,102,255,0.15) 0%, transparent 60%);
  --gradient-blue-purple: linear-gradient(135deg, #0066FF 0%, #8B5CF6 100%);
  --gradient-cyan: linear-gradient(135deg, #06B6D4 0%, #3B82F6 100%);
  
  /* Glass Morphism */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.18);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
  --glass-blur: blur(20px);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.08);
  --shadow-xl: 0 24px 64px rgba(0,0,0,0.12);
  --shadow-blue: 0 12px 32px rgba(0,102,255,0.25);
  --shadow-blue-lg: 0 24px 64px rgba(0,102,255,0.3);
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
  --radius-full: 9999px;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Consolas", monospace;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  --space-5xl: 128px;
  
  /* Container */
  --container-max: 1200px;
  --container-narrow: 800px;
  --container-wide: 1400px;
  
  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.container-wide {
  max-width: var(--container-wide);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 2.5vw, 1.75rem); }
h4 { font-size: clamp(1.125rem, 2vw, 1.375rem); }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-center { text-align: center; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  white-space: nowrap;
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-blue-lg);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn-ghost:hover {
  color: var(--color-primary);
  background: var(--color-bg-alt);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 8px 20px;
  font-size: 0.875rem;
}

.btn-block {
  width: 100%;
}

/* Header / Navigation */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
}

.site-header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-deep);
  text-decoration: none;
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.125rem;
  font-weight: 800;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--color-primary);
  background: rgba(0, 102, 255, 0.06);
}

.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--color-border);
  padding: var(--space-sm);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition-base);
}

.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown a {
  display: block;
  padding: 8px 12px;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-dropdown a:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 8px;
  cursor: pointer;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
}

/* Hero Section */
.hero {
  position: relative;
  min-height: 600px;
  padding: 120px 0 80px;
  background: var(--gradient-hero);
  overflow: hidden;
  display: flex;
  align-items: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-glow);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  top: 20%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(6,182,212,0.12) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 6px 16px;
  background: rgba(0, 102, 255, 0.15);
  border: 1px solid rgba(0, 102, 255, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  color: #60A5FA;
  margin-bottom: var(--space-lg);
}

.hero h1 {
  color: white;
  font-size: clamp(2.2rem, 5.5vw, 3.8rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-lg);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.6;
  margin-bottom: var(--space-xl);
  max-width: 600px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-lg);
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-meta-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.hero-meta-label {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero-meta-value {
  font-size: 1rem;
  font-weight: 600;
  color: white;
}

.hero-image {
  position: absolute;
  right: 5%;
  top: 50%;
  transform: translateY(-50%);
  width: 45%;
  max-width: 500px;
  z-index: 1;
}

.hero-image img {
  width: 100%;
  border-radius: var(--radius-2xl);
  box-shadow: 0 40px 80px rgba(0,0,0,0.4);
}

/* Sections */
.section {
  padding: var(--space-4xl) 0;
}

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

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto var(--space-3xl);
}

.section-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 800;
  margin-bottom: var(--space-md);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* Cards */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--color-border);
}

.card-glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

.card-gradient {
  background: var(--gradient-deep);
  color: white;
  border: none;
}

.card-gradient h3, .card-gradient h4 {
  color: white;
}

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
  color: white;
  font-size: 1.5rem;
}

.card-icon-cyan { background: var(--gradient-cyan); }
.card-icon-purple { background: var(--gradient-blue-purple); }
.card-icon-deep { background: var(--gradient-deep); }

/* Grid */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Download Buttons */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-md);
}

.download-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--space-xl);
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
  cursor: pointer;
}

.download-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-blue);
  transform: translateY(-4px);
}

.download-card-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
  color: white;
}

.download-card-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.download-card-desc {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
}

/* FAQ Accordion */
.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-md);
  overflow: hidden;
  transition: all var(--transition-base);
}

.faq-item.active {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--color-primary);
  transition: transform var(--transition-base);
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
  padding: 0 var(--space-lg);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding-bottom: var(--space-lg);
}

.faq-answer p {
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-xs);
  padding: var(--space-md) 0;
  font-size: 0.875rem;
}

.breadcrumb a {
  color: var(--color-text-tertiary);
}

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

.breadcrumb-separator {
  color: var(--color-text-tertiary);
}

.breadcrumb-current {
  color: var(--color-text-secondary);
  font-weight: 500;
}

/* Article Layout */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-2xl);
  align-items: start;
}

.article-main {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--space-3xl);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
}

.article-sidebar {
  position: sticky;
  top: 88px;
}

.article-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border-light);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 4px;
}

.article-toc {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.article-toc-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.article-toc ol {
  list-style: decimal;
  padding-left: var(--space-lg);
}

.article-toc li {
  margin-bottom: var(--space-xs);
  font-size: 0.875rem;
}

.article-toc a {
  color: var(--color-text-secondary);
}

.article-toc a:hover {
  color: var(--color-primary);
}

.article-content {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text);
}

.article-content h2 {
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  font-size: 1.5rem;
}

.article-content h3 {
  margin-top: var(--space-xl);
  margin-bottom: var(--space-md);
  font-size: 1.25rem;
}

.article-content p {
  margin-bottom: var(--space-md);
  color: var(--color-text-secondary);
}

.article-content ul, .article-content ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

.article-content ul li {
  list-style: disc;
  margin-bottom: var(--space-sm);
  color: var(--color-text-secondary);
}

.article-content ol li {
  list-style: decimal;
  margin-bottom: var(--space-sm);
  color: var(--color-text-secondary);
}

.article-content strong {
  color: var(--color-text);
  font-weight: 600;
}

.article-content blockquote {
  border-left: 4px solid var(--color-primary);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-md);
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
}

.article-content code {
  font-family: var(--font-mono);
  background: var(--color-bg-alt);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.875em;
  color: var(--color-primary);
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--space-md);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.article-content th {
  background: var(--color-bg-alt);
  padding: var(--space-md);
  text-align: left;
  font-weight: 600;
  font-size: 0.9rem;
}

.article-content td {
  padding: var(--space-md);
  border-top: 1px solid var(--color-border-light);
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.article-content img {
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-md);
}

.article-footer {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border-light);
}

.article-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

.article-nav-item {
  padding: var(--space-lg);
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.article-nav-item:hover {
  background: var(--color-surface);
  box-shadow: var(--shadow-md);
}

.article-nav-label {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-xs);
}

.article-nav-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text);
}

/* Sidebar Widgets */
.sidebar-widget {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--color-border-light);
  margin-bottom: var(--space-lg);
}

.sidebar-widget-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-primary);
}

.sidebar-list li {
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-border-light);
}

.sidebar-list li:last-child {
  border-bottom: none;
}

.sidebar-list a {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.sidebar-list a:hover {
  color: var(--color-primary);
}

.sidebar-list-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: var(--radius-sm);
  background: var(--color-bg-alt);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-tertiary);
  flex-shrink: 0;
}

/* Stats */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.stat-item {
  text-align: center;
}

.stat-value {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
}

/* Testimonials */
.testimonial-card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
}

.testimonial-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.testimonial-rating {
  display: flex;
  gap: 2px;
  margin-bottom: var(--space-md);
  color: #FBBF24;
}

.testimonial-text {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.testimonial-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 0.9rem;
}

.testimonial-name {
  font-size: 0.9rem;
  font-weight: 600;
}

.testimonial-role {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

/* CTA Section */
.cta-section {
  position: relative;
  padding: var(--space-4xl) 0;
  background: var(--gradient-deep);
  text-align: center;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-glow);
}

.cta-content {
  position: relative;
  z-index: 2;
  max-width: 640px;
  margin: 0 auto;
}

.cta-content h2 {
  color: white;
  margin-bottom: var(--space-md);
}

.cta-content p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 1.125rem;
  margin-bottom: var(--space-xl);
}

/* Tags */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--color-bg-alt);
  color: var(--color-text-secondary);
}

.tag-primary {
  background: rgba(0, 102, 255, 0.1);
  color: var(--color-primary);
}

.tag-success {
  background: rgba(16, 185, 129, 0.1);
  color: #059669;
}

.tag-warning {
  background: rgba(245, 158, 11, 0.1);
  color: #D97706;
}

/* Alert Box */
.alert {
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-md);
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
}

.alert-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.alert-info {
  background: rgba(0, 102, 255, 0.05);
  border: 1px solid rgba(0, 102, 255, 0.15);
  color: var(--color-primary);
}

.alert-warning {
  background: rgba(245, 158, 11, 0.05);
  border: 1px solid rgba(245, 158, 11, 0.15);
  color: #D97706;
}

.alert-success {
  background: rgba(16, 185, 129, 0.05);
  border: 1px solid rgba(16, 185, 129, 0.15);
  color: #059669;
}

/* Steps */
.steps {
  counter-reset: step;
}

.step-item {
  position: relative;
  padding-left: 56px;
  padding-bottom: var(--space-xl);
}

.step-item:last-child {
  padding-bottom: 0;
}

.step-item::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  z-index: 2;
}

.step-item::after {
  content: '';
  position: absolute;
  left: 19px;
  top: 40px;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
}

.step-item:last-child::after {
  display: none;
}

.step-title {
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.step-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

/* QR Code */
.qr-code-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-xl);
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-md);
}

.qr-code-img {
  width: 180px;
  height: 180px;
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-md);
  background: white;
  padding: var(--space-sm);
}

.qr-code-label {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-align: center;
}

/* Version Timeline */
.version-timeline {
  position: relative;
  padding-left: var(--space-xl);
}

.version-timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
}

.version-item {
  position: relative;
  padding-bottom: var(--space-xl);
}

.version-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--gradient-primary);
  border: 3px solid var(--color-bg);
}

.version-item:last-child {
  padding-bottom: 0;
}

.version-number {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.version-date {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-sm);
}

.version-changes {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.version-changes li {
  list-style: disc;
  margin-left: var(--space-md);
  margin-bottom: 4px;
}

/* Floating Customer Service */
.floating-service {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.floating-btn {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-blue);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 1.5rem;
}

.floating-btn:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-blue-lg);
}

.floating-panel {
  position: absolute;
  right: 0;
  bottom: 70px;
  width: 280px;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--color-border);
  padding: var(--space-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition-base);
}

.floating-panel.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.floating-panel-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
  text-align: center;
}

.floating-panel-wechat {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(0, 200, 83, 0.08);
  border-radius: var(--radius-lg);
  font-size: 1.1rem;
  font-weight: 700;
  color: #07C160;
  letter-spacing: 0.05em;
}

.floating-panel-desc {
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
  margin-top: var(--space-sm);
}

/* Footer */
.site-footer {
  background: var(--gradient-deep);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-4xl) 0 var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.footer-brand {
  max-width: 320px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 800;
  color: white;
  margin-bottom: var(--space-md);
}

.footer-desc {
  font-size: 0.875rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.5);
}

.footer-col-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: white;
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-col ul li {
  margin-bottom: var(--space-sm);
}

.footer-col ul li a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: white;
}

.footer-bottom {
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-bottom p {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.4);
  margin: 0;
}

.footer-links {
  display: flex;
  gap: var(--space-md);
}

.footer-links a {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.4);
}

.footer-links a:hover {
  color: white;
}

/* Friend Links */
.friend-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: center;
}

.friend-link {
  padding: 6px 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.friend-link:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* Page Hero (for subpages) */
.page-hero {
  position: relative;
  padding: 120px 0 60px;
  background: var(--gradient-hero);
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-glow);
}

.page-hero-content {
  position: relative;
  z-index: 2;
}

.page-hero h1 {
  color: white;
  margin-bottom: var(--space-md);
}

.page-hero p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 1.125rem;
  max-width: 640px;
}

/* Page Hero Download CTA */
.page-hero-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

.page-hero-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.page-hero-btn svg {
  width: 20px;
  height: 20px;
}

.page-hero-btn-primary {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  color: white;
  box-shadow: 0 8px 24px rgba(0, 242, 254, 0.35);
}

.page-hero-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(0, 242, 254, 0.45);
}

.page-hero-btn-outline {
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(8px);
}

.page-hero-btn-outline:hover {
  background: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-2px);
}

@media (max-width: 640px) {
  .page-hero-cta {
    flex-direction: column;
    align-items: stretch;
  }

  .page-hero-btn {
    width: 100%;
    padding: 0.85rem 1rem;
  }
}

/* Hub Layout */
.hub-grid {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-2xl);
  align-items: start;
}

.hub-main {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  border: 1px solid var(--color-border-light);
}

.hub-sidebar {
  position: sticky;
  top: 88px;
}

/* Related Articles */
.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.related-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
}

.related-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.related-card-img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.related-card-body {
  padding: var(--space-md);
}

.related-card-title {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  line-height: 1.4;
}

.related-card-meta {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

/* Tabs */
.tabs {
  display: flex;
  gap: var(--space-xs);
  border-bottom: 2px solid var(--color-border);
  margin-bottom: var(--space-xl);
  overflow-x: auto;
}

.tab {
  padding: var(--space-md) var(--space-lg);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.tab:hover {
  color: var(--color-primary);
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* Animation Classes */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  font-size: 0.7rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-new { background: #DCFCE7; color: #16A34A; }
.badge-hot { background: #FEE2E2; color: #DC2626; }
.badge-rec { background: #DBEAFE; color: #2563EB; }

/* Divider */
.divider {
  height: 1px;
  background: var(--color-border-light);
  margin: var(--space-xl) 0;
}

/* Content Image */
.content-img {
  width: 100%;
  border-radius: var(--radius-lg);
  margin: var(--space-md) 0;
  box-shadow: var(--shadow-md);
}

/* Summary Box */
.summary-box {
  background: linear-gradient(135deg, rgba(0,102,255,0.05) 0%, rgba(6,182,212,0.05) 100%);
  border: 1px solid rgba(0,102,255,0.15);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-xl);
  margin-bottom: var(--space-xl);
}

.summary-box p {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text);
  margin: 0;
}

/* Responsive */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .article-layout, .hub-grid {
    grid-template-columns: 1fr;
  }
  .article-sidebar, .hub-sidebar {
    position: static;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .related-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-image {
    display: none;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: var(--space-md);
    box-shadow: var(--shadow-lg);
    border-top: 1px solid var(--color-border);
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    padding-left: var(--space-md);
  }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }

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

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

  .article-main, .hub-main {
    padding: var(--space-lg);
  }

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

  .article-nav {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: 500px;
    padding: 100px 0 60px;
  }

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

  .floating-service {
    right: 16px;
    bottom: 16px;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-actions {
    flex-direction: column;
  }
  
  .hero-actions .btn {
    width: 100%;
  }
}

/* Print */
@media print {
  .site-header, .site-footer, .floating-service, .nav-toggle {
    display: none;
  }
  
  body {
    color: black;
    background: white;
  }
}

/* Selection */
::selection {
  background: rgba(0, 102, 255, 0.2);
  color: var(--color-text);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-alt);
}

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

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

/* ============================================
   下载CTA按钮
   ============================================ */
.download-cta {
  text-align: center;
  margin: var(--space-2xl) 0;
  padding: var(--space-2xl) var(--space-lg);
  background: linear-gradient(135deg, rgba(0,102,255,0.04) 0%, rgba(6,182,212,0.04) 100%);
  border: 2px dashed rgba(0,102,255,0.2);
  border-radius: var(--radius-xl);
}

.download-cta-hint {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-lg);
}

.download-cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 16px 48px;
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  background: var(--gradient-primary);
  border: none;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-blue);
  cursor: pointer;
  transition: all var(--transition-base);
  letter-spacing: 0.02em;
  min-width: 260px;
}

.download-cta-btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-blue-lg);
  color: #fff;
}

.download-cta-btn:active {
  transform: translateY(0);
}

.download-cta-btn svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.download-cta-subs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.download-cta-subs a {
  font-size: 0.825rem;
  color: var(--color-text-secondary);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  background: var(--color-bg-alt);
  transition: all var(--transition-fast);
}

.download-cta-subs a:hover {
  color: var(--color-primary);
  background: rgba(0,102,255,0.08);
}

/* ============================================
   下载弹窗 (Download Modal)
   ============================================ */
.download-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(10, 22, 40, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.download-modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.download-modal {
  position: relative;
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  width: 90%;
  max-width: 420px;
  padding: var(--space-3xl) var(--space-2xl);
  text-align: center;
  transform: translateY(20px);
  transition: all var(--transition-base);
}

.download-modal-overlay.active .download-modal {
  transform: translateY(0);
}

.download-modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--color-text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-bg-alt);
}

.download-modal-close:hover {
  background: #FEE2E2;
  color: #DC2626;
}

.download-modal-icon {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--gradient-primary);
  margin: 0 auto var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-blue);
}

.download-modal-icon svg {
  width: 36px;
  height: 36px;
  color: white;
}

.download-modal h3 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.download-modal p {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xl);
  line-height: 1.6;
}

.download-modal-wechat {
  background: linear-gradient(135deg, rgba(7,193,96,0.06) 0%, rgba(7,193,96,0.02) 100%);
  border: 1px solid rgba(7,193,96,0.15);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.download-modal-wechat-label {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-sm);
}

.download-modal-wechat-id {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-size: 1.5rem;
  font-weight: 800;
  color: #07C160;
  letter-spacing: 0.15em;
  cursor: pointer;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  user-select: all;
}

.download-modal-wechat-id:hover {
  background: rgba(7,193,96,0.08);
}

.download-modal-wechat-id .copy-hint {
  font-size: 0.75rem;
  font-weight: 500;
  color: #07C160;
  background: rgba(7,193,96,0.1);
  padding: 2px 10px;
  border-radius: var(--radius-full);
  letter-spacing: normal;
}

.download-modal-copy-btn {
  width: 100%;
  padding: 14px 24px;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #07C160 0%, #06AD56 100%);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: 0 8px 24px rgba(7,193,96,0.3);
  letter-spacing: 0.02em;
}

.download-modal-copy-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(7,193,96,0.4);
  color: #fff;
}

.download-modal-copy-btn.copied {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  box-shadow: var(--shadow-blue);
}

.download-modal-copy-btn.copied:hover {
  box-shadow: var(--shadow-blue-lg);
}

/* 响应式 */
@media (max-width: 480px) {
  .download-modal {
    padding: var(--space-2xl) var(--space-lg);
    border-radius: var(--radius-xl);
  }

  .download-cta-btn {
    width: 100%;
    min-width: auto;
    padding: 14px 32px;
  }
}