/* ==========================================================================
   吹雪云 (Chui Xue Yun) - 官方推广落地页核心样式表
   风格：黑白极简 (Black & White Minimalist)
   设计原则：黑白灰纯粹配色、大留白、粗圆字体层级、克制微动效、极速响应
   ========================================================================== */

:root {
  --bg-color: #0c0d0e;
  --bg-card: #141517;
  --bg-card-hover: #1c1d20;
  --bg-surface: #1e2024;
  --border-color: #27292d;
  --border-light: #383a40;
  --text-primary: #ffffff;
  --text-secondary: #a0a4ab;
  --text-muted: #6a6f78;
  --accent-white: #ffffff;
  --accent-gray: #d4d4d8;
  --badge-bg: rgba(255, 255, 255, 0.08);
  --badge-border: rgba(255, 255, 255, 0.16);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 9999px;
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-base: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-float: 0 12px 36px rgba(0, 0, 0, 0.6);
  --container-max: 1200px;
  --header-height: 72px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-heading: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

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

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: var(--font-stack);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
}

/* 粗圆风格标题与品牌字样 */
h1, h2, h3, h4, .brand-title, .brand-text {
  font-family: var(--font-heading);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  line-height: 1.25;
}

p {
  color: var(--text-secondary);
  font-size: 1rem;
}

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

img, svg {
  display: block;
  max-width: 100%;
}

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

/* 键盘可访问性焦点反馈 */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--accent-white);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* 容器规范 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 顶部页眉 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(12, 13, 14, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition-fast);
}

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

.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.brand-logo-link:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.brand-logo-img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.brand-tag {
  font-size: 0.72rem;
  padding: 2px 8px;
  background: var(--badge-bg);
  border: 1px solid var(--badge-border);
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  font-weight: 500;
  letter-spacing: 0.05em;
}

/* 导航链接 */
.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 28px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 6px 2px;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-white);
  transition: width var(--transition-fast);
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.nav-link-highlight {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--badge-bg);
  border: 1px solid var(--badge-border);
  color: var(--text-primary);
  font-weight: 600;
}

.nav-link-highlight:hover {
  background: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.3);
}

.header-cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 18px;
  font-size: 0.9rem;
  font-weight: 700;
  border-radius: var(--radius-pill);
  background: var(--text-primary);
  color: var(--bg-color);
  transition: all var(--transition-fast);
}

.header-cta-btn:hover {
  background: var(--accent-gray);
  transform: translateY(-1px);
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

/* 通用按钮系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-pill);
  text-align: center;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-primary {
  background: #ffffff;
  color: #0c0d0e;
  border: 1px solid #ffffff;
}

.btn-primary:hover {
  background: #e4e4e7;
  border-color: #e4e4e7;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 255, 255, 0.15);
}

.btn-secondary {
  background: transparent;
  color: #ffffff;
  border: 1px solid var(--border-light);
}

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

.btn-lg {
  padding: 14px 34px;
  font-size: 1.05rem;
}

.btn-block {
  width: 100%;
}

/* 通用章节样式 */
.section-block {
  padding: 96px 0;
  border-bottom: 1px solid var(--border-color);
  position: relative;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  padding: 4px 14px;
  background: var(--badge-bg);
  border: 1px solid var(--badge-border);
  border-radius: var(--radius-pill);
  color: var(--accent-gray);
  margin-bottom: 16px;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 64px auto;
}

.section-title {
  font-size: 2.25rem;
  margin-bottom: 16px;
}

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

/* ==========================================================================
   主视觉 (Hero Section)
   桌面端双栏（左文案，右动态图卡矩阵），移动端单栏
   ========================================================================== */
.hero-section {
  padding: 80px 0 100px 0;
  min-height: calc(100vh - var(--header-height));
  display: flex;
  align-items: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-headline {
  font-size: 3.2rem;
  line-height: 1.15;
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}

.hero-headline-accent {
  color: #ffffff;
  display: inline-block;
  position: relative;
}

.hero-headline-accent::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 0;
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.25);
  border-radius: 4px;
  z-index: -1;
}

.hero-description {
  font-size: 1.18rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 580px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.hero-meta-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.03);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-color);
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 0 8px rgba(255, 255, 255, 0.8);
}

/* Hero 右侧动态卡片矩阵 */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-card-stack {
  width: 100%;
  max-width: 480px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.hero-status-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-float);
  transition: transform var(--transition-base), border-color var(--transition-base);
}

.hero-status-card:hover {
  border-color: var(--border-light);
  transform: translateY(-3px);
}

.card-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

.card-top-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

.live-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-light);
  color: #ffffff;
}

.metrics-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  text-align: center;
  margin-bottom: 20px;
}

.metric-item {
  background: var(--bg-surface);
  padding: 12px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.metric-val {
  font-size: 1.35rem;
  font-weight: 900;
  color: #ffffff;
  display: block;
}

.metric-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.node-list-mini {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.node-item-mini {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
}

.node-name {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--text-primary);
}

.node-flag {
  font-size: 0.75rem;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 4px;
  background: #ffffff;
  color: #000000;
}

.node-ping {
  font-family: monospace;
  font-weight: 700;
  color: var(--accent-gray);
  font-size: 0.8rem;
}

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

.advantage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
}

.advantage-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-subtle);
}

.adv-icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.adv-title {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.adv-desc {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-secondary);
}

/* ==========================================================================
   流媒体与 AI 支持 (Streaming & AI Support)
   ========================================================================== */
.support-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
}

.support-subgrid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}

.support-column h3 {
  font-size: 1.3rem;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.support-pill {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.support-pill:hover {
  border-color: var(--border-light);
  background: rgba(255, 255, 255, 0.05);
}

.support-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  background: #ffffff;
  color: #000000;
  font-weight: 900;
  font-size: 0.85rem;
  flex-shrink: 0;
}

.support-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

.support-note {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.support-disclaimer {
  padding: 18px 24px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text-muted);
}

/* ==========================================================================
   套餐对比 (Plan Comparison)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-base);
}

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

.pricing-card-featured {
  background: #17181c;
  border: 2px solid #ffffff;
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: #ffffff;
  color: #000000;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 16px;
  border-radius: var(--radius-pill);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.plan-header {
  margin-bottom: 24px;
}

.plan-name {
  font-size: 1.4rem;
  margin-bottom: 6px;
}

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

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 20px 0;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.plan-currency {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-primary);
}

.plan-price {
  font-size: 3rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.plan-period {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 36px;
  flex-grow: 1;
}

.plan-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.feature-check {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  margin-top: 2px;
  color: #ffffff;
}

.pricing-notes {
  margin-top: 40px;
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ==========================================================================
   常见问题 (FAQ Accordion)
   ========================================================================== */
.faq-list {
  max-width: 860px;
  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 var(--transition-fast);
}

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

.faq-question {
  width: 100%;
  padding: 22px 28px;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  background: none;
  cursor: pointer;
}

.faq-toggle-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base), padding var(--transition-base);
  padding: 0 28px;
}

.faq-item.active .faq-answer {
  max-height: 400px;
  padding: 0 28px 24px 28px;
}

.faq-answer p {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

/* ==========================================================================
   右侧悬浮章节导航 (Chapter Navigation)
   按页面章节顺序移动、根据滚动位置判定、到达边界禁用、不遮挡移动端内容
   ========================================================================== */
.chapter-nav-floating {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  background: rgba(20, 21, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-pill);
  padding: 10px 6px;
  box-shadow: var(--shadow-subtle);
  transition: all var(--transition-base);
}

.chapter-btn {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--text-primary);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
  position: relative;
}

.chapter-btn:hover:not(:disabled) {
  background: #ffffff;
  color: #000000;
  border-color: #ffffff;
  transform: scale(1.08);
}

.chapter-btn:disabled {
  opacity: 0.25;
  cursor: not-allowed;
  pointer-events: none;
}

.chapter-indicator {
  font-size: 0.68rem;
  font-weight: 800;
  color: var(--text-muted);
  padding: 4px 0;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.08em;
  user-select: none;
}

/* ==========================================================================
   页脚 (Footer)
   仅保留“网站地图”“关于我们”“服务条款”“隐私政策”四个入口，新标签页打开
   ========================================================================== */
.site-footer {
  background: #080809;
  border-top: 1px solid var(--border-color);
  padding: 64px 0 40px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border-color);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-links-grid {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.footer-link-item {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 4px 0;
}

.footer-link-item:hover {
  color: #ffffff;
}

.footer-link-item::after {
  content: "↗";
  font-size: 0.75rem;
  margin-left: 4px;
  opacity: 0.7;
}

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

.footer-domain {
  font-family: monospace;
  padding: 2px 8px;
  background: var(--bg-surface);
  border-radius: 4px;
  border: 1px solid var(--border-color);
  color: var(--accent-gray);
}

/* ==========================================================================
   知识科普与独立文章页通用样式 (Articles & Pages)
   ========================================================================== */
.page-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 64px 24px 100px 24px;
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

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

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

.article-title {
  font-size: 2.4rem;
  line-height: 1.25;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.article-body {
  color: #d1d5db;
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-body h2 {
  font-size: 1.65rem;
  margin: 48px 0 20px 0;
  color: #ffffff;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 1.25rem;
  margin: 32px 0 14px 0;
  color: #f3f4f6;
}

.article-body p {
  margin-bottom: 20px;
  color: #d1d5db;
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 28px;
}

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

.article-body blockquote {
  border-left: 3px solid #ffffff;
  background: var(--bg-card);
  padding: 16px 24px;
  margin: 24px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--accent-gray);
  font-style: italic;
}

.article-callout {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 32px 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.article-callout-title {
  font-weight: 800;
  font-size: 1.1rem;
  color: #ffffff;
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.95rem;
}

.article-table th, .article-table td {
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  text-align: left;
}

.article-table th {
  background: var(--bg-surface);
  color: #ffffff;
  font-weight: 700;
}

.article-table tr:nth-child(even) {
  background: rgba(255, 255, 255, 0.02);
}

/* 文章列表网格 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 40px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-base);
}

.article-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-subtle);
}

.article-card-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-gray);
  margin-bottom: 12px;
  display: inline-block;
}

.article-card-title {
  font-size: 1.35rem;
  line-height: 1.4;
  margin-bottom: 12px;
  color: #ffffff;
}

.article-card-excerpt {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
}

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

.article-read-btn {
  font-weight: 700;
  color: #ffffff;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ==========================================================================
   响应式媒体查询 (Mobile-first & Desktop Adjustments)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-headline {
    font-size: 2.6rem;
  }
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }
  .support-subgrid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .articles-grid {
    grid-template-columns: 1fr;
  }
}

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

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

  .mobile-menu-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: #0c0d0e;
    border-bottom: 1px solid var(--border-color);
    padding: 24px;
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    box-shadow: var(--shadow-float);
  }

  .nav-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    width: 100%;
  }

  .nav-link {
    font-size: 1.1rem;
    width: 100%;
    display: block;
    padding: 8px 0;
  }

  .header-cta-btn {
    width: 100%;
  }

  .hero-section {
    padding: 40px 0 60px 0;
    min-height: auto;
  }

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

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

  .hero-description {
    font-size: 1rem;
  }

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

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

  .advantages-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .support-wrapper {
    padding: 24px 18px;
  }

  .support-pill-grid {
    grid-template-columns: 1fr;
  }

  .section-block {
    padding: 64px 0;
  }

  .section-title {
    font-size: 1.8rem;
  }

  .footer-top {
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
  }

  .footer-links-grid {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  /* 移动端章节浮动导航按规范优化：置于右下侧水平胶囊，不遮挡正文与按钮 */
  .chapter-nav-floating {
    top: auto;
    bottom: 20px;
    right: 16px;
    transform: none;
    flex-direction: row;
    padding: 6px 10px;
    background: rgba(15, 16, 18, 0.92);
  }

  .chapter-indicator {
    writing-mode: horizontal-tb;
    padding: 0 4px;
    font-size: 0.72rem;
  }
}

/* 尊重用户的减少动效偏好 */
@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;
  }
}