/* 狗狗加速 (Gougou Accelerator) - 极简高能浅色设计系统 */

:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --accent-color: #0284c7;
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #0284c7 100%);
  --cta-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --cta-shadow: 0 10px 25px -5px rgba(37, 99, 235, 0.4);
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-subtle: #f1f5f9;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
  --shadow-hover: 0 20px 30px -10px rgba(37, 99, 235, 0.15);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
}

/* 全局基础设置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 统一按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1.05rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: var(--cta-gradient);
  color: #ffffff;
  box-shadow: var(--cta-shadow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 30px -5px rgba(37, 99, 235, 0.5);
  filter: brightness(1.05);
}

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

.btn-secondary:hover {
  background-color: var(--bg-subtle);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

.btn-block {
  width: 100%;
}

/* 顶部导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.header-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  border: 2px solid var(--primary-light);
  background: var(--bg-subtle);
}

.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 0.98rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s;
}

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

.nav-cta {
  padding: 10px 22px;
  font-size: 0.95rem;
}

/* Hero 主视觉区 */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  background: radial-gradient(circle at 50% 20%, rgba(37, 99, 235, 0.08) 0%, transparent 60%);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -1px;
  color: var(--text-main);
  margin-bottom: 20px;
}

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

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 780px;
  margin: 0 auto 36px;
  font-weight: 400;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-highlights {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  font-size: 0.95rem;
  color: var(--text-light);
}

.highlight-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 通用 Banner / Section Title */
.section {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 56px;
}

.section-tag {
  font-size: 0.88rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary-color);
  letter-spacing: 1px;
  margin-bottom: 12px;
  display: block;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* 核心优势 Grid */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.adv-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.adv-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(37, 99, 235, 0.3);
}

.adv-icon {
  width: 56px;
  height: 56px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.adv-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.adv-card p {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.6;
}

/* 流媒体与 AI 支持 */
.support-bg {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.support-card {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  transition: all 0.25s ease;
}

.support-card:hover {
  border-color: var(--primary-color);
  background: #ffffff;
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.support-icon {
  font-size: 2.2rem;
  margin-bottom: 12px;
}

.support-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 6px;

}

.support-card p {
  font-size: 0.88rem;
  color: var(--text-light);
}

/* 价格套餐对比表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch;
}

.price-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.price-card:hover {
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-color);
}

.price-card.popular {
  border: 2px solid var(--primary-color);
  box-shadow: var(--shadow-lg);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--cta-gradient);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
}

.price-header {
  text-align: center;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.price-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.price-amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.price-amount span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-light);
}

.price-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.price-features li {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.price-features li::before {
  content: "✓";
  color: var(--primary-color);
  font-weight: 800;
}

/* 用户评价 */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: var(--shadow-sm);
}

.rating {
  color: #f59e0b;
  font-size: 1rem;
  margin-bottom: 16px;
}

.testimonial-text {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
  font-style: italic;
}

.user-profile {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.user-info h5 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

.user-info p {
  font-size: 0.82rem;
  color: var(--text-light);
}

/* 原生折叠 FAQ 常见问题 */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s;
}

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

.faq-summary {
  padding: 20px 24px;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary::after {
  content: "+";
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--text-light);
  transition: transform 0.2s;
}

.faq-item[open] .faq-summary::after {
  content: "−";
  color: var(--primary-color);
}

.faq-content {
  padding: 0 24px 20px;
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 底部 CTA 区域 */
.cta-banner {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
  color: #ffffff;
  border-radius: 28px;
  padding: 60px 40px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  margin: 40px auto 80px;
}

.cta-banner h2 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-banner p {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.cta-banner .btn-primary {
  background: #ffffff;
  color: var(--primary-color);
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.cta-banner .btn-primary:hover {
  background: #f8fafc;
  color: var(--primary-hover);
}

/* 页脚 (Footer) - 严格保留 4 个标题链接 */
.footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  margin-bottom: 24px;
}

.footer-nav a {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.2s;
}

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

.copyright {
  font-size: 0.88rem;
  color: var(--text-light);
}

/* 子页面独立通用布局 (About, Terms, Privacy, Sitemap) */
.page-header {
  padding: 60px 0 40px;
  text-align: center;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 12px;
}

.page-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
}

.content-box {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  margin: 40px auto 80px;
  box-shadow: var(--shadow-sm);
  max-width: 900px;
}

.content-box h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 32px 0 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary-light);
}

.content-box h2:first-child {
  margin-top: 0;
}

.content-box p {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 16px;
}

.content-box ul {
  margin-bottom: 20px;
  padding-left: 24px;
}

.content-box li {
  font-size: 0.98rem;
  color: var(--text-muted);
  margin-bottom: 10px;
  line-height: 1.6;
}

/* 网站地图层级 */
.sitemap-tree {
  list-style: none;
  padding: 0;
}

.sitemap-tree > li {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.sitemap-tree ul {
  list-style: disc;
  margin-top: 10px;
  margin-left: 28px;
  font-weight: 400;
}

.sitemap-tree ul li {
  font-size: 1rem;
  margin-bottom: 8px;
}

.sitemap-tree a {
  color: var(--primary-color);
}

.sitemap-tree a:hover {
  text-decoration: underline;
}

/* 响应式媒体查询 (Mobile Single-Column) */
@media (max-width: 992px) {
  .advantages-grid,
  .pricing-grid,
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .header-nav {
    height: 70px;
  }
  
  .nav-links {
    display: none; /* 移动端保持极简直接突出按钮 */
  }

  .hero {
    padding: 50px 0 40px;
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .advantages-grid,
  .support-grid,
  .pricing-grid,
  .testimonials-grid {
    grid-template-columns: 1fr;
  }

  .cta-banner {
    padding: 40px 20px;
    border-radius: var(--radius-lg);
  }

  .cta-banner h2 {
    font-size: 1.6rem;
  }

  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }

  .content-box {
    padding: 24px;
    margin: 20px auto 40px;
  }
}

/* 文章高科技网格卡片 Grid Cards */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 36px;
}

.article-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.article-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--cta-gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.article-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(37, 99, 235, 0.4);
}

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

.article-card-tag {
  display: inline-block;
  padding: 4px 12px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
  align-self: flex-start;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 12px;
}

.article-card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-light);
}

.article-read-link {
  color: var(--primary-color);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.2s;
}

.article-read-link:hover {
  gap: 8px;
}

@media (max-width: 992px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .articles-grid {
    grid-template-columns: 1fr;
  }
}

/* Hero 主视觉图片展示区 */
.hero-image-container {
  margin-top: 40px;
  position: relative;
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

.hero-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 50px -12px rgba(37, 99, 235, 0.25), 0 10px 15px -3px rgba(0, 0, 0, 0.05);
  border: 4px solid #ffffff;
  display: block;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-img:hover {
  transform: translateY(-4px);
  box-shadow: 0 30px 60px -15px rgba(37, 99, 235, 0.35);
}