/* ==========================================================================
   海獭 HaiTa 网络加速器 - 极速原生 CSS 设计系统
   ========================================================================== */

/* 1. CSS 变量与全局重置 */
:root {
  --bg-dark: #070a12;
  --bg-card: rgba(15, 23, 42, 0.7);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-color-glow: rgba(0, 210, 255, 0.3);

  --primary-cyan: #00D2FF;
  --primary-blue: #3B82F6;
  --primary-indigo: #6366F1;
  --accent-green: #10B981;
  --accent-purple: #8B5CF6;
  --accent-amber: #F59E0B;

  --gradient-main: linear-gradient(135deg, #00D2FF 0%, #3B82F6 50%, #6366F1 100%);
  --gradient-glow: linear-gradient(135deg, rgba(0,210,255,0.4) 0%, rgba(99,102,241,0.4) 100%);
  --gradient-text: linear-gradient(135deg, #FFFFFF 30%, #7DD3FC 70%, #00D2FF 100%);
  --gradient-card-border: linear-gradient(135deg, rgba(0,210,255,0.4), rgba(255,255,255,0.05));

  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-subtle: #64748B;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --container-max: 1200px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* 无障碍跳转入口 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--primary-cyan);
  color: #070a12;
  font-weight: 800;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  z-index: 9999;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
  outline: 3px solid #FFFFFF;
}

/* 无障碍高亮焦点框 */
:focus-visible {
  outline: 2px solid var(--primary-cyan);
  outline-offset: 3px;
}

/* 锚点定位避免固定页眉遮挡 */
section[id], header[id], main[id] {
  scroll-margin-top: 90px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  line-height: 1.6;
  background: radial-gradient(circle at 50% 0%, #0f172a 0%, #070a12 70%);
  min-height: 100vh;
}

/* 2. 通用与版式 */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

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

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: rgba(0, 210, 255, 0.1);
  border: 1px solid rgba(0, 210, 255, 0.25);
  border-radius: var(--radius-full);
  color: var(--primary-cyan);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 4rem auto;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  line-height: 1.2;
}

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

/* 3. 按钮样式 (规范重点：CTA 大按钮适配 touch + 光效) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.875rem 2rem;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  white-space: nowrap;
  border: none;
  min-height: 48px;
}

.btn-primary {
  background: var(--gradient-main);
  color: #FFFFFF;
  box-shadow: 0 4px 20px rgba(0, 210, 255, 0.35);
  position: relative;
  overflow: hidden;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 210, 255, 0.55);
  opacity: 0.95;
}

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

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.btn-glow {
  animation: pulse-glow 2.5s infinite;
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 15px rgba(0, 210, 255, 0.4); }
  50% { box-shadow: 0 0 30px rgba(0, 210, 255, 0.7); }
}

/* 4. 顶栏 Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 1.25rem 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(7, 10, 18, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 0.875rem 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--gradient-main);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px rgba(0, 210, 255, 0.4);
}

.logo-icon svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: #FFFFFF;
  stroke-width: 2.2;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--primary-cyan);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 0.5rem;
}

/* 5. Hero 头部主视觉区 */
.hero {
  padding: 9rem 0 5rem 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 210, 255, 0.15) 0%, rgba(99, 102, 241, 0.05) 50%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3.5rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content h1 {
  font-size: 3.25rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.trust-badges {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  flex-wrap: wrap;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.trust-item svg {
  color: var(--accent-green);
  width: 18px;
  height: 18px;
}

/* Hero Widget 卡片动画 */
.hero-widget {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  backdrop-filter: blur(16px);
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  position: relative;
}

.hero-widget::after {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: linear-gradient(135deg, rgba(0,210,255,0.4), transparent 60%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.widget-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--accent-green);
  font-weight: 600;
}

.dot-pulse {
  width: 10px;
  height: 10px;
  background: var(--accent-green);
  border-radius: 50%;
  position: relative;
}

.dot-pulse::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: var(--accent-green);
  opacity: 0.4;
  animation: ping 1.8s cubic-bezier(0, 0, 0.2, 1) infinite;
}

@keyframes ping {
  75%, 100% { transform: scale(2); opacity: 0; }
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.03);
  padding: 0.875rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.node-flag {
  font-size: 1.25rem;
}

.node-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.node-ping {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: monospace;
  font-size: 0.875rem;
  color: var(--accent-green);
  font-weight: 700;
}

/* 6. 产品核心优势卡片 (3 大图文卡片) */
.features-section {
  padding: 6rem 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-color-glow);
  transform: translateY(-6px);
  box-shadow: 0 15px 35px rgba(0, 210, 255, 0.15);
}

.feature-icon-wrapper {
  width: 60px;
  height: 60px;
  background: rgba(0, 210, 255, 0.1);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--primary-cyan);
}

.feature-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.875rem;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 7. 流媒体与 AI 支持图卡 */
.media-ai-section {
  padding: 6rem 0;
  background: rgba(15, 23, 42, 0.4);
  border-y: 1px solid var(--border-color);
}

.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  backdrop-filter: blur(12px);
}

.category-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.category-badge {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
}

.badge-ai {
  background: rgba(99, 102, 241, 0.15);
  color: #A5B4FC;
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge-media {
  background: rgba(245, 158, 11, 0.15);
  color: #FDE047;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.service-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
  margin-top: 1.5rem;
}

.service-chip {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
}

.service-chip:hover {
  border-color: var(--primary-cyan);
  background: rgba(0, 210, 255, 0.08);
}

.chip-icon {
  width: 20px;
  height: 20px;
}

/* 8. 套餐价格对比表 */
.pricing-section {
  padding: 7rem 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.95) 0%, rgba(30, 41, 59, 0.9) 100%);
  border-color: var(--primary-cyan);
  box-shadow: 0 0 35px rgba(0, 210, 255, 0.25);
  transform: scale(1.04);
}

.popular-ribbon {
  position: absolute;
  top: 0;
  right: 2.5rem;
  transform: translateY(-50%);
  background: var(--gradient-main);
  color: #FFFFFF;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.plan-desc {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
  min-height: 40px;
}

.plan-price {
  margin-bottom: 2rem;
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}

.price-currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-cyan);
}

.price-amount {
  font-size: 3.25rem;
  font-weight: 900;
  line-height: 1;
}

.price-period {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.plan-features {
  list-style: none;
  margin-bottom: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.925rem;
  color: var(--text-main);
}

.plan-features li svg {
  color: var(--accent-green);
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* 9. 用户评价 */
.reviews-section {
  padding: 6rem 0;
  background: rgba(15, 23, 42, 0.3);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.stars {
  color: var(--accent-amber);
  margin-bottom: 1rem;
  display: flex;
  gap: 0.2rem;
}

.review-text {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  font-style: italic;
  line-height: 1.6;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 0.875rem;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
  color: #FFFFFF;
}

.user-details h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

.user-details p {
  font-size: 0.8rem;
  color: var(--text-subtle);
}

/* 10. FAQ 手风琴 (6 个常见问题 - 原生 details/summary 无障碍与 JS 兼容) */
.faq-section {
  padding: 6rem 0;
}

.faq-accordion {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

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

.faq-item[open], .faq-item.active {
  border-color: rgba(0, 210, 255, 0.4);
  background: var(--bg-card-hover);
}

.faq-question {
  padding: 1.5rem 1.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-size: 1.1rem;
  font-weight: 700;
  user-select: none;
  list-style: none;
}

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

.faq-icon {
  width: 24px;
  height: 24px;
  color: var(--primary-cyan);
  transition: var(--transition);
  flex-shrink: 0;
}

.faq-item[open] .faq-icon, .faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.75rem 1.5rem 1.75rem;
  color: var(--text-muted);
  font-size: 0.975rem;
  line-height: 1.7;
}

/* 11. 规定页脚：只保留 4 个标题且新页面打开 */
.footer {
  background: #04060c;
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 3rem 0;
}

.footer-top {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin-bottom: 3rem;
}

.footer-brand {
  margin-bottom: 2rem;
}

/* 按照规范：页脚只保留这四个标题链接，内容打开新页面展示 */
.footer-nav-titles {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3rem;
  list-style: none;
  flex-wrap: wrap;
}

.footer-title-link {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: var(--transition);
}

.footer-title-link:hover {
  color: var(--primary-cyan);
  border-color: var(--primary-cyan);
  background: rgba(0, 210, 255, 0.08);
  transform: translateY(-2px);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-subtle);
  font-size: 0.875rem;
}

/* 12. 全响应式适配 (@media 手机单栏化) */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content h1 {
    font-size: 2.5rem;
  }

  .hero-cta {
    justify-content: center;
  }

  .trust-badges {
    justify-content: center;
  }

  .features-grid, .pricing-grid, .reviews-grid {
    grid-template-columns: 1fr;
  }

  .pricing-card.featured {
    transform: none;
  }

  .media-ai-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* 手机端抽屉菜单 */
  }

  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: #090d16;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
  }

  .mobile-toggle {
    display: block;
  }

  .hero-content h1 {
    font-size: 2.1rem;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .footer-nav-titles {
    gap: 1rem;
    flex-direction: column;
    width: 100%;
  }

  .footer-title-link {
    width: 100%;
    text-align: center;
  }
}

/* 13. 无障碍动画减弱支持 */
@media (prefers-reduced-motion: reduce) {
  *, ::before, ::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}