/* ==========================================================================
   vyprvpn - 奢华极简风格设计系统 (Luxury Minimalist Design System)
   调性：黑色与奶油白沉稳交融、高级衬线体、精致间距、粗圆品牌标题、克制微动效
   ========================================================================== */

:root {
  /* 奢华极简配色方案 (Luxury Minimalism Palette) */
  --bg-base: #fcfbf8;
  /* 温暖纯粹奶油白底色 */
  --bg-surface: #ffffff;
  /* 纯白主卡片面 */
  --bg-subtle: #f6f3ed;
  /* 柔和奶油暖灰衬底 */
  --bg-dark: #111215;
  /* 沉稳黑曜石背景 */
  --bg-dark-card: #191b20;
  /* 深色卡片背景 */
  --bg-dark-card-hover: #22252c;

  /* 文字层次 */
  --text-main: #141518;
  /* 极深黑曜石主文字 */
  --text-secondary: #525660;
  /* 沉稳暖炭灰副文字 */
  --text-muted: #888e99;
  /* 细腻石墨浅灰 */
  --text-on-dark: #fcfbf8;
  /* 暗底文字 */
  --text-on-dark-subtle: #9ea3ae;

  /* 奢华点缀色：香槟金 / 古典青铜 */
  --color-gold: #b38838;
  /* 雅致香槟金 */
  --color-gold-hover: #cba04c;
  /* 悬停高光金 */
  --color-gold-soft: #fbf5e9;
  /* 金色浅柔底色 */
  --color-gold-border: #e3d2b2;
  /* 金色发丝边框 */
  --color-accent-black: #111215;
  /* 核心纯黑按钮与徽章 */

  /* 边框与发丝线 (精细间距与发丝级勾勒) */
  --border-light: #e8e3da;
  /* 浅奶油灰边框 */
  --border-subtle: #f1ede5;
  /* 极轻微边框 */
  --border-gold: #dfcca9;
  /* 金色微边框 */
  --border-dark: #272a33;
  /* 深色微边框 */

  /* 阴影体系：克制、柔和、高级 */
  --shadow-sm: 0 2px 10px rgba(17, 18, 21, 0.03);
  --shadow-md: 0 8px 28px rgba(17, 18, 21, 0.05);
  --shadow-lg: 0 16px 48px rgba(17, 18, 21, 0.08);

  /* 字体系统：粗圆品牌风格 + 奢华衬线标题 + 高阅读性无衬线正文 */
  --font-brand: ui-rounded, "SF Pro Rounded", "Hiragino Maru Gothic ProN", "Microsoft YaHei UI", sans-serif;
  --font-serif: "Songti SC", "Noto Serif CJK SC", "STSong", "Source Han Serif CN", Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* 布局与精致间距 */
  --header-height: 76px;
  --container-max: 1180px;
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 9999px;
  --transition: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 基础重置 */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  background-color: var(--bg-base);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.8;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 尊重用户减弱动效偏好 */
@media (prefers-reduced-motion: reduce) {

  *,
  *::before,
  *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
    scroll-behavior: auto !important;
  }
}

/* 容器定义 */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 28px;
}

/* 链接样式 */
a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

/* 粗圆字体类 */
.font-brand {
  font-family: var(--font-brand);
}

/* 衬线字体类 */
.font-serif {
  font-family: var(--font-serif);
}

/* ==========================================================================
   1. Site Header (页眉：Logo、章节导航、知识科普入口)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(252, 251, 248, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

/* Brand Logo (粗圆风格，点击返回顶部) */
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  text-decoration: none;
  color: var(--text-main);
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--bg-dark);
  color: var(--color-gold);
  border: 1px solid var(--border-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.brand-logo:hover .brand-icon {
  transform: scale(1.04);
  color: var(--color-gold-hover);
  border-color: var(--color-gold);
}

.brand-logo span {
  font-family: var(--font-brand);
  font-size: 1.42rem;
  font-weight: 800;
  letter-spacing: -0.4px;
}

/* 导航链接 */
.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--text-main);
  background: var(--bg-subtle);
}

.nav-link.active {
  color: var(--text-main);
  font-weight: 600;
}

.nav-link.home-return {
  color: var(--color-gold);
  font-weight: 600;
}

.nav-link.home-return:hover {
  background: var(--color-gold-soft);
}

/* 知识科普入口徽章 */
.knowledge-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-gold-soft);
  color: var(--color-gold);
  border: 1px solid var(--color-gold-border);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-weight: 600;
}

.knowledge-badge:hover {
  background: var(--color-gold);
  color: #ffffff;
  border-color: var(--color-gold);
}

/* 移动端汉堡菜单按钮 */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-main);
  padding: 8px;
  border-radius: var(--radius-sm);
}

.mobile-toggle:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

/* ==========================================================================
   2. Hero 主视觉 (桌面随机错落图卡簇，手机上下排列；奢华极简与粗圆品牌主标题)
   ========================================================================== */
.hero-section {
  padding: 84px 0 96px;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border-light);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}

.hero-text-col {
  max-width: 620px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 6px 14px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-pill);
  color: var(--color-gold);
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 3.1rem;
  line-height: 1.25;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.hero-title span {
  font-family: var(--font-brand);
  font-weight: 800;
  color: var(--color-gold);
  letter-spacing: -0.03em;
}

.hero-desc {
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}

/* 按钮规范 (清晰悬停、点击、键盘焦点反馈) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 30px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
  text-align: center;
}

.btn:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 3px;
}

.btn-primary {
  background: var(--bg-dark);
  color: #ffffff;
  border-color: var(--bg-dark);
  box-shadow: 0 4px 14px rgba(17, 18, 21, 0.14);
}

.btn-primary:hover {
  background: #252830;
  border-color: #252830;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(17, 18, 21, 0.2);
}

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

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-light);
}

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

.btn-gold {
  background: var(--color-gold);
  color: #ffffff;
  border-color: var(--color-gold);
}

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

.hero-trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
}

.hero-trust-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.hero-trust-item svg {
  color: var(--color-gold);
  flex-shrink: 0;
}

/* 桌面端错落动态图卡簇 (Cluster Cards) */
.hero-card-cluster {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  position: relative;
}

.cluster-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  position: relative;
}

.cluster-card:nth-child(1) {
  transform: translateY(-8px);
}

.cluster-card:nth-child(4) {
  transform: translateY(8px);
}

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

.cluster-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.cluster-icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--color-gold-soft);
  color: var(--color-gold);
  display: flex;
  align-items: center;
  justify-content: center;
}

.cluster-badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

.cluster-value {
  font-family: var(--font-brand);
  font-size: 2.1rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.15;
  margin-bottom: 6px;
}

.cluster-label {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ==========================================================================
   3. 通用 Section 基础样式与精致间距
   ========================================================================== */
.section-block {
  padding: 108px 0;
  border-bottom: 1px solid var(--border-light);
  position: relative;
}

.bg-alt {
  background: var(--bg-subtle);
}

.section-header {
  text-align: center;
  max-width: 740px;
  margin: 0 auto 64px;
}

.section-pill {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gold);
  background: var(--color-gold-soft);
  border: 1px solid var(--color-gold-border);
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  margin-bottom: 16px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.32;
  margin-bottom: 18px;
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* ==========================================================================
   4. Core Advantages 核心优势 (6 个奢华图文卡片)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 36px 30px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

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

.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  color: var(--color-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
}

.feature-card h3 {
  font-family: var(--font-brand);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 14px;
  line-height: 1.35;
}

.feature-card p {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* ==========================================================================
   5. Streaming & AI Ecosystem 流媒体与 AI 支持
   ========================================================================== */
.ecosystem-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 36px;
  margin-bottom: 40px;
}

.eco-group {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 38px 32px;
  box-shadow: var(--shadow-sm);
}

.eco-group-title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 16px;
}

.eco-group-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 24px;
}

.eco-badges-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.eco-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-main);
  transition: var(--transition);
}

.eco-badge:hover {
  background: var(--color-gold-soft);
  border-color: var(--color-gold-border);
  transform: translateX(3px);
}

.eco-badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-gold);
  flex-shrink: 0;
}

.eco-disclaimer {
  max-width: 960px;
  margin: 0 auto;
  padding: 20px 24px;
  background: var(--bg-surface);
  border: 1px dashed var(--border-gold);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   6. Pricing Plans 套餐对比 (清晰展示名称、价格、周期、流量及购买按钮)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.pricing-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 36px 26px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

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

/* 推荐套餐高亮 (沉稳黑曜石背景与香槟金) */
.pricing-card.featured {
  background: var(--bg-dark);
  color: var(--text-on-dark);
  border-color: var(--color-gold);
  box-shadow: 0 16px 40px rgba(17, 18, 21, 0.18);
  transform: scale(1.03);
  z-index: 2;
}

.pricing-card.featured:hover {
  transform: scale(1.05) translateY(-4px);
}

.pricing-featured-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-gold);
  color: #ffffff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  text-transform: uppercase;
  white-space: nowrap;
}

.pricing-name {
  font-family: var(--font-brand);
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 6px;
}

.pricing-card.featured .pricing-name {
  color: #ffffff;
}

.pricing-cycle {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.pricing-card.featured .pricing-cycle {
  color: var(--text-on-dark-subtle);
}

.pricing-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 12px;
}

.pricing-currency {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-gold);
}

.pricing-amount {
  font-family: var(--font-brand);
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1;
}

.pricing-period {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.pricing-card.featured .pricing-period {
  color: var(--text-on-dark-subtle);
}

.pricing-traffic {
  font-family: var(--font-brand);
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-gold);
  background: var(--color-gold-soft);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 24px;
  border: 1px solid var(--color-gold-border);
}

.pricing-card.featured .pricing-traffic {
  background: rgba(179, 136, 56, 0.16);
  border-color: rgba(179, 136, 56, 0.4);
  color: #f1cf88;
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pricing-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.pricing-card.featured .pricing-feature-item {
  color: #d1d5db;
}

.pricing-feature-item svg {
  color: var(--color-gold);
  flex-shrink: 0;
  margin-top: 2px;
}

.pricing-btn {
  width: 100%;
}

.pricing-data-note {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==========================================================================
   7. User Reviews 用户评价 (真实严谨维度评价)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 34px 28px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

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

.review-rating {
  color: var(--color-gold);
  font-size: 1.15rem;
  letter-spacing: 2px;
  margin-bottom: 16px;
}

.review-text {
  font-family: var(--font-serif);
  font-size: 0.98rem;
  color: var(--text-main);
  line-height: 1.8;
  margin-bottom: 24px;
  flex-grow: 1;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 18px;
  border-top: 1px solid var(--border-subtle);
}

.review-avatar-text {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--bg-subtle);
  border: 1px solid var(--border-light);
  color: var(--color-gold);
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.review-user-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

.review-user-role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==========================================================================
   8. FAQ 常见问题 (手风琴折叠交互)
   ========================================================================== */
.faq-list {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-item:hover {
  border-color: var(--border-gold);
}

.faq-question {
  width: 100%;
  padding: 24px 28px;
  background: none;
  border: none;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  cursor: pointer;
  font-family: var(--font-brand);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  transition: var(--transition);
}

.faq-question:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: -2px;
}

.faq-icon {
  width: 20px;
  height: 20px;
  color: var(--color-gold);
  transition: transform 0.28s ease;
  flex-shrink: 0;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  padding: 0 28px;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 28px 26px;
  transition: max-height 0.4s ease-in-out;
}

.faq-answer p {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ==========================================================================
   9. Footer 页脚 (仅保留网站地图、关于我们、服务条款、隐私政策 4 个入口，新标签页打开)
   ========================================================================== */
.site-footer {
  background: var(--bg-dark);
  color: var(--text-on-dark);
  padding: 72px 0 48px;
  border-top: 1px solid var(--border-dark);
}

.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--border-dark);
  margin-bottom: 32px;
}

.footer-brand {
  font-family: var(--font-brand);
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.4px;
}

.footer-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.footer-nav-link {
  font-size: 0.92rem;
  color: var(--text-on-dark-subtle);
  transition: var(--transition);
}

.footer-nav-link:hover {
  color: var(--color-gold);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-on-dark-subtle);
  flex-wrap: wrap;
  gap: 16px;
}

/* ==========================================================================
   10. 浮动章节箭头导航 (上一章节 / 下一章节；根据滚动精准定位，边界禁用，防遮挡)
   ========================================================================== */
.section-nav-arrows {
  position: fixed;
  right: 28px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.arrow-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  color: var(--text-main);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

.arrow-btn:hover:not(:disabled) {
  background: var(--bg-dark);
  color: #ffffff;
  border-color: var(--bg-dark);
  transform: scale(1.08);
}

.arrow-btn:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

.arrow-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none;
  background: var(--bg-subtle);
  border-color: var(--border-subtle);
  color: var(--text-muted);
}

/* ==========================================================================
   11. 文章页、关于我们、条款与政策专属排版 (Article & Legal Layout)
   ========================================================================== */
.page-header {
  padding: 64px 0 40px;
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border-light);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

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

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

.article-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 16px;
  flex-wrap: wrap;
}

.article-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 64px 28px 96px;
}

.article-content {
  font-size: 1.02rem;
  line-height: 1.95;
  color: var(--text-main);
}

.article-content h2 {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 48px 0 20px;
  line-height: 1.35;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-light);
}

.article-content h3 {
  font-family: var(--font-brand);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 32px 0 14px;
}

.article-content p {
  margin-bottom: 22px;
  color: var(--text-secondary);
}

.article-content ul,
.article-content ol {
  margin: 0 0 24px 24px;
  color: var(--text-secondary);
}

.article-content li {
  margin-bottom: 10px;
}

.article-content blockquote {
  margin: 28px 0;
  padding: 20px 24px;
  background: var(--bg-subtle);
  border-left: 4px solid var(--color-gold);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.96rem;
  color: var(--text-main);
}

.article-cta-box {
  margin: 56px 0 24px;
  padding: 40px 32px;
  background: var(--bg-dark);
  color: #ffffff;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-dark);
  text-align: center;
}

.article-cta-box h4 {
  font-family: var(--font-brand);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.article-cta-box p {
  color: var(--text-on-dark-subtle);
  margin-bottom: 28px;
  max-width: 580px;
  margin-left: auto;
  margin-right: auto;
}

.article-cta-box .btn {
  background: var(--color-gold);
  color: #ffffff;
  border-color: var(--color-gold);
}

.article-cta-box .btn:hover {
  background: var(--color-gold-hover);
  border-color: var(--color-gold-hover);
}

/* ==========================================================================
   12. 响应式布局媒体查询 (移动端优先与精细适配)
   ========================================================================== */
@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .site-header {
    border-bottom: 1px solid var(--border-light);
  }

  .mobile-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-light);
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px;
    gap: 12px;
    box-shadow: var(--shadow-lg);
  }

  .site-nav.mobile-open {
    display: flex;
  }

  .site-nav .nav-link {
    width: 100%;
    padding: 10px 14px;
  }

  .knowledge-badge {
    width: 100%;
    justify-content: center;
  }

  /* Hero 手机端上下单栏排布 */
  .hero-section {
    padding: 48px 0 64px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-title {
    font-size: 2.2rem;
  }

  .hero-card-cluster {
    grid-template-columns: 1fr;
  }

  .cluster-card:nth-child(1),
  .cluster-card:nth-child(4) {
    transform: none;
  }

  .section-block {
    padding: 72px 0;
  }

  .section-title {
    font-size: 1.85rem;
  }

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

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

  .eco-badges-list {
    grid-template-columns: 1fr;
  }

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

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

  .pricing-card.featured:hover {
    transform: translateY(-4px);
  }

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

  .footer-top {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
  }

  .footer-nav {
    flex-wrap: wrap;
    gap: 18px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  /* 移动端章节箭头精巧缩小，避开正文遮挡 */
  .section-nav-arrows {
    right: 12px;
    bottom: 24px;
    top: auto;
    transform: none;
    gap: 8px;
  }

  .arrow-btn {
    width: 38px;
    height: 38px;
    opacity: 0.9;
  }
}