/* ========================================
   Civigenesis 公司官网 - 全局样式
   ======================================== */

/* CSS 变量 - 品牌色彩 */
:root {
  /* 主色调 */
  --bg-dark: #0A0F1F;
  --bg-secondary: #111827;
  --bg-card: #1A2236;
  
  /* 科技蓝 */
  --primary-blue: #2A6DF4;
  --primary-blue-hover: #1E55D9;
  
  /* 银色 */
  --silver: #A0AEC0;
  --silver-light: #CBD5E0;
  
  /* 金色 - Beyond Skyrim 点缀色 */
  --gold: #C89F3B;
  --gold-hover: #D4AF4E;
  
  /* 文字颜色 */
  --text-primary: #FFFFFF;
  --text-secondary: #A0AEC0;
  --text-muted: #718096;
  
  /* 渐变 */
  --gradient-blue: linear-gradient(135deg, #2A6DF4 0%, #1E40AF 100%);
  --gradient-gold: linear-gradient(135deg, #C89F3B 0%, #8B6914 100%);
  
  /* 间距 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  
  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.75rem;
  --radius-lg: 1.5rem;
  --radius-full: 9999px;
  
  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(42, 109, 244, 0.3);
  
  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ========================================
   基础重置与字体
   ======================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); }
h2 { font-size: clamp(2rem, 4vw, 3.5rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h4 { font-size: clamp(1.25rem, 2vw, 1.5rem); }

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

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

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

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

/* ========================================
   工具类
   ======================================== */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.container-narrow {
  max-width: 1000px;
}

.text-center { text-align: center; }
.text-gold { color: var(--gold); }
.text-blue { color: var(--primary-blue); }

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

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.section-header h2 {
  margin-bottom: var(--spacing-sm);
}

.section-header p {
  font-size: 1.25rem;
  max-width: 700px;
  margin: 0 auto;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 15, 31, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(10, 15, 31, 0.98);
  box-shadow: var(--shadow-md);
}

.navbar-container {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  max-width: 1400px;
  margin: 0 auto;
  gap: var(--spacing-md);
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--text-primary);
}

.navbar-logo svg {
  width: 40px;
  height: 40px;
}

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

.navbar-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  list-style: none;
}

.navbar-menu a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  position: relative;
}

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

.navbar-menu a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--primary-blue);
  border-radius: var(--radius-full);
}

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

/* 语言切换（右上角） */
.navbar-lang {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.9rem;
  font-weight: 500;
}

.navbar-lang a {
  color: var(--text-muted);
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
  text-decoration: none;
}

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

.navbar-lang a.lang-active {
  color: var(--text-primary);
  pointer-events: none;
}

.navbar-lang .lang-sep {
  color: var(--text-muted);
  opacity: 0.6;
  user-select: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.95rem;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.btn-gold {
  background: var(--gradient-gold);
  color: var(--text-primary);
}

.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(200, 159, 59, 0.4);
}

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

.btn-outline:hover {
  border-color: var(--primary-blue);
  color: var(--primary-blue);
}

/* 置灰状态（功能待开放） */
.btn-disabled,
.btn-disabled:hover {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
  transform: none;
}
.btn-primary.btn-disabled {
  background: var(--bg-secondary);
  border-color: var(--border);
  color: var(--text-muted);
}
.btn-outline.btn-disabled {
  border-color: var(--border);
  color: var(--text-muted);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.1rem;
}

/* GitHub Stars 按钮 */
.github-stars {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-card);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  color: var(--text-primary);
  transition: all var(--transition-base);
}

.github-stars:hover {
  background: var(--bg-secondary);
  transform: translateY(-2px);
}

.github-stars svg {
  width: 20px;
  height: 20px;
}

.stars-count {
  font-weight: 600;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.mobile-menu-btn span {
  width: 25px;
  height: 2px;
  background: var(--text-primary);
  transition: all var(--transition-fast);
}

/* ========================================
   页脚
   ======================================== */
.footer {
  background: var(--bg-secondary);
  padding: var(--spacing-lg) 0 var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-brand {
  max-width: 300px;
}

.footer-brand .navbar-logo {
  margin-bottom: var(--spacing-sm);
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-links h4 {
  font-size: 1rem;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

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

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

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

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

.footer-social,
.footer-channels {
  margin-top: var(--spacing-sm);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--bg-card);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: all var(--transition-base);
}

.footer-social a:hover {
  background: var(--primary-blue);
  color: var(--text-primary);
  transform: translateY(-3px);
}

.footer-channels-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm) var(--spacing-md);
  margin-top: var(--spacing-xs);
  font-size: 0.9rem;
}

.footer-channels-row:first-child {
  margin-top: 0;
}

.footer-channels-row a,
.footer-channels-row span {
  color: var(--text-muted);
  transition: color var(--transition-base);
}

.footer-channels-row a:hover {
  color: var(--primary-blue);
}

.footer-channels-row .channel-sep {
  color: var(--text-muted);
  opacity: 0.6;
}

/* 联系我们渠道 - 仅 logo，三行：4+4+2 */
.footer-contacts {
  margin-top: var(--spacing-sm);
}

.footer-contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-xs);
}

.footer-contact-row:first-child {
  margin-top: 0;
}

/* 可点击的 logo 链接：仅图标 */
a.footer-contact-item {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition-base);
}

a.footer-contact-item:hover {
  background: rgba(42, 109, 244, 0.25);
  color: var(--primary-blue);
  border-color: rgba(42, 109, 244, 0.4);
}

a.footer-contact-item svg,
a.footer-contact-item i {
  width: 18px;
  height: 18px;
  font-size: 1.125rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* 微信/QQ：图标 + 账号 */
.footer-contact-item.footer-contact-wechat-qq {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-contact-item .footer-contact-icon {
  width: 36px;
  height: 36px;
  min-width: 36px;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-contact-item .footer-contact-icon svg,
.footer-contact-item .footer-contact-icon i {
  width: 18px;
  height: 18px;
  font-size: 1.125rem;
  color: var(--text-secondary);
}

.footer-contact-value {
  font-size: 0.85rem;
  color: var(--text-muted);
}

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

.footer-bottom p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-brand-bar {
  display: flex;
  gap: var(--spacing-md);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-brand-bar span {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xl) 0;
  overflow: hidden;
}

.hero-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 1000px;
  padding: 0 var(--spacing-md);
}

.hero-content h1 {
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content .subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.hero-brand-relationship {
  background: rgba(42, 109, 244, 0.1);
  border: 1px solid rgba(42, 109, 244, 0.3);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  backdrop-filter: blur(10px);
}

.hero-brand-relationship p {
  font-size: 1.2rem;
  color: var(--text-primary);
  margin: 0;
}

.hero-brand-relationship strong {
  color: var(--primary-blue);
}

.hero-cta {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* ========================================
   卡片组件
   ======================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-md);
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-blue);
  transform: scaleX(0);
  transition: transform var(--transition-base);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(42, 109, 244, 0.3);
}

.card:hover::before {
  transform: scaleX(1);
}

.card-gold::before {
  background: var(--gradient-gold);
}

.card-gold:hover {
  border-color: rgba(200, 159, 59, 0.3);
}

.card-icon {
  width: 60px;
  height: 60px;
  background: rgba(42, 109, 244, 0.2);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-sm);
}

.card-gold .card-icon {
  background: rgba(200, 159, 59, 0.2);
}

.card-icon svg {
  width: 30px;
  height: 30px;
  color: var(--primary-blue);
}

.card-gold .card-icon svg {
  color: var(--gold);
}

.card h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-xs);
}

.card p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

/* ========================================
   数据统计
   ======================================== */
.stats-section {
  background: var(--bg-secondary);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  text-align: center;
}

.stat-item {
  padding: var(--spacing-md);
}

.stat-number {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--primary-blue);
  font-family: 'Montserrat', sans-serif;
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* ========================================
   代码块
   ======================================== */
.code-block {
  background: var(--bg-dark);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  overflow-x: auto;
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-family: 'Fira Code', 'Monaco', 'Consolas', monospace;
  font-size: 0.9rem;
  line-height: 1.8;
}

.code-block code {
  color: var(--text-secondary);
}

.code-block .command {
  color: var(--primary-blue);
}

.code-block .comment {
  color: var(--text-muted);
}

/* ========================================
   特性网格
   ======================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-sm);
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.feature-item svg {
  width: 24px;
  height: 24px;
  color: var(--primary-blue);
  flex-shrink: 0;
  margin-top: 3px;
}

.feature-item span {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ========================================
   实验卡片
   ======================================== */
.experiment-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: all var(--transition-base);
}

.experiment-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(200, 159, 59, 0.3);
}

.experiment-canvas {
  width: 100%;
  height: 200px;
  background: var(--bg-dark);
}

.experiment-content {
  padding: var(--spacing-md);
}

.experiment-content h3 {
  color: var(--gold);
  margin-bottom: var(--spacing-xs);
}

.experiment-content .progress {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-sm);
  font-style: italic;
}

.experiment-buttons {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  margin-top: var(--spacing-sm);
}

.experiment-buttons .btn {
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
}

/* ========================================
   定价卡片
   ======================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.pricing-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  transition: all var(--transition-base);
  position: relative;
}

.pricing-card.featured {
  border-color: var(--primary-blue);
  box-shadow: var(--shadow-glow);
}

.pricing-card.featured::before {
  content: '推荐';
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  background: var(--gradient-blue);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
}

.pricing-card h3 {
  margin-bottom: var(--spacing-xs);
}

.pricing-card .price {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-blue);
  margin-bottom: var(--spacing-sm);
}

.pricing-card .price span {
  font-size: 1rem;
  color: var(--text-muted);
}

.pricing-card ul {
  list-style: none;
  margin: var(--spacing-md) 0;
  text-align: left;
}

.pricing-card li {
  padding: var(--spacing-xs) 0;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.pricing-card li svg {
  width: 18px;
  height: 18px;
  color: var(--primary-blue);
  flex-shrink: 0;
}

/* ========================================
   联系表单
   ======================================== */
.contact-form {
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-xs);
  color: var(--text-primary);
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(42, 109, 244, 0.2);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

/* ========================================
   时间轴
   ======================================== */
.timeline {
  position: relative;
  max-width: 800px;
  margin: var(--spacing-lg) auto;
  padding: var(--spacing-md) 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100%;
  background: rgba(255, 255, 255, 0.1);
}

.timeline-item {
  display: flex;
  justify-content: flex-end;
  padding: var(--spacing-md) 0;
  position: relative;
  width: 50%;
}

.timeline-item:nth-child(odd) {
  align-self: flex-start;
  justify-content: flex-end;
  padding-right: var(--spacing-lg);
  text-align: right;
}

.timeline-item:nth-child(even) {
  align-self: flex-end;
  justify-content: flex-start;
  margin-left: 50%;
  padding-left: var(--spacing-lg);
  text-align: left;
}

.timeline-item::before {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  background: var(--primary-blue);
  border-radius: 50%;
  top: 50%;
  transform: translateY(-50%);
}

.timeline-item:nth-child(odd)::before {
  right: -8px;
}

.timeline-item:nth-child(even)::before {
  left: -8px;
}

.timeline-content {
  background: var(--bg-card);
  padding: var(--spacing-sm);
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.timeline-content h4 {
  color: var(--gold);
  margin-bottom: var(--spacing-xs);
}

.timeline-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin: 0;
}

/* ========================================
   打字机效果
   ======================================== */
.typewriter {
  overflow: hidden;
  border-right: 3px solid var(--gold);
  white-space: nowrap;
  animation: typing 3.5s steps(40, end), blink-caret 0.75s step-end infinite;
  max-width: fit-content;
  margin: 0 auto;
}

@keyframes typing {
  from { width: 0; }
  to { width: 100%; }
}

@keyframes blink-caret {
  from, to { border-color: transparent; }
  50% { border-color: var(--gold); }
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .navbar-container {
    grid-template-columns: 1fr auto auto;
  }
  
  .navbar-center {
    justify-self: end;
  }
  
  .mobile-menu-btn {
    display: flex;
  }
  
  .navbar-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--bg-dark);
    flex-direction: column;
    padding: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
  }
  
  .navbar-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .navbar-cta {
    display: none;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .footer-brand {
    max-width: 100%;
  }
  
  .footer-social {
    justify-content: center;
  }

  .footer-channels-row {
    justify-content: center;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-brand-bar {
    justify-content: center;
    flex-wrap: wrap;
  }
  
  .timeline::before {
    left: 20px;
  }
  
  .timeline-item,
  .timeline-item:nth-child(odd),
  .timeline-item:nth-child(even) {
    width: 100%;
    margin-left: 0;
    padding-left: 60px;
    padding-right: 0;
    text-align: left;
    justify-content: flex-start;
  }
  
  .timeline-item::before,
  .timeline-item:nth-child(odd)::before,
  .timeline-item:nth-child(even)::before {
    left: 12px;
    right: auto;
  }
  
  .hero-content h1 {
    font-size: 2.5rem;
  }
  
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
}

@media (max-width: 480px) {
  .cards-grid,
  .features-grid,
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .hero-brand-relationship p {
    font-size: 1rem;
  }
}

/* ========================================
   动画类
   ======================================== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* 页面过渡 */
.page-transition {
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}