/* ==========================================================================
   肯の基 (kfc-jc.lol) - 核心样式表
   视觉风格：黑白极简、经典质感、移动优先、无重型依赖
   ========================================================================== */

:root {
  /* 基础调色板：纯黑白灰与细腻阶梯 */
  --bg-page: #ffffff;
  --bg-card: #ffffff;
  --bg-subtle: #f9fafb;
  --bg-muted: #f3f4f6;
  --bg-dark: #121212;
  --bg-dark-card: #1c1c1e;
  
  --text-main: #111827;
  --text-muted: #4b5563;
  --text-light: #9ca3af;
  --text-white: #ffffff;
  
  --border-light: #e5e7eb;
  --border-subtle: #f0f0f0;
  --border-dark: #27272a;
  
  --brand-black: #09090b;
  --brand-white: #fafafa;
  --brand-accent: #27272a;

  /* 阴影体系：极轻微的高级漫射 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 12px 24px -4px rgba(0, 0, 0, 0.12);

  /* 字体家族：优先本地/系统粗圆体与现代无衬线 */
  --font-brand: "YouYuan", "Yuanti SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* 布局与尺寸 */
  --container-max: 1140px;
  --header-height: 72px;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;

  /* 过渡曲线 */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

/* 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%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.65;
  font-feature-settings: "cv02", "cv03", "cv04", "cv11";
  overflow-x: hidden;
  position: relative;
}

/* 无障碍跳过链接 */
.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  background: var(--brand-black);
  color: var(--brand-white);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  text-decoration: none;
  font-weight: 600;
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: 16px;
}

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

/* 章节通用 */
.section {
  padding: 80px 0;
  position: relative;
}
.section-alt {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  background: var(--bg-muted);
  border: 1px solid var(--border-light);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.section-title {
  font-family: var(--font-brand);
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--text-main);
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 链接与按钮交互 */
a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

:focus-visible {
  outline: 2px solid var(--brand-black);
  outline-offset: 3px;
}

/* 核心按钮体系 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap;
  min-height: 46px;
}

.btn-primary {
  background-color: var(--brand-black);
  color: var(--brand-white);
  border: 1px solid var(--brand-black);
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover {
  background-color: #27272a;
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background-color: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border-light);
}
.btn-secondary:hover {
  background-color: var(--bg-muted);
  border-color: #d1d5db;
  color: #000000;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1.05rem;
  min-height: 52px;
}

/* ==========================================================================
   页眉与导航 (Header & Nav)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  transition: background-color var(--transition-normal);
}

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

.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  border-radius: var(--radius-sm);
}
.brand-logo-link img {
  display: block;
  height: 38px;
  width: auto;
}

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

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 6px 4px;
  border-radius: var(--radius-sm);
  position: relative;
}
.nav-link:hover {
  color: var(--text-main);
}
.nav-link.active {
  color: var(--brand-black);
  font-weight: 700;
}

.nav-badge-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-muted);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  border: 1px solid var(--border-light);
}
.nav-badge-link:hover {
  background: #e5e7eb;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* 汉堡按钮 */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  gap: 5px;
}
.menu-bar {
  width: 22px;
  height: 2px;
  background-color: var(--text-main);
  transition: all var(--transition-normal);
}

/* 移动端菜单弹窗 */
.nav-mobile-layer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(16px);
  z-index: 99;
  padding: 24px;
  flex-direction: column;
  gap: 20px;
  overflow-y: auto;
  border-top: 1px solid var(--border-light);
}
.nav-mobile-layer.is-open {
  display: flex;
}
.nav-mobile-layer .nav-link {
  font-size: 1.15rem;
  padding: 12px 0;
  border-bottom: 1px solid var(--border-subtle);
}

/* ==========================================================================
   主视觉 (Hero Section)
   桌面端文案与动态图卡随机/网格交错排列，手机端上下排列
   ========================================================================== */
.hero-section {
  padding: 70px 0 90px;
  overflow: hidden;
  background: radial-gradient(circle at 50% 20%, #f9fafb 0%, #ffffff 80%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-badge-wrap {
  margin-bottom: 20px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: var(--bg-muted);
  border: 1px solid var(--border-light);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}
.hero-badge .status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #111111;
}

.hero-title {
  font-family: var(--font-brand);
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.03em;
  color: var(--brand-black);
  margin-bottom: 24px;
}
.hero-title span.highlight {
  position: relative;
  display: inline-block;
  background: linear-gradient(180deg, transparent 65%, #e5e7eb 65%);
}

.hero-lead {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 36px;
  max-width: 580px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  margin-bottom: 32px;
}

.hero-sub-note {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-light);
}
.hero-sub-note span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Hero 右侧动态图卡视觉容器 */
.hero-visual-board {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.floating-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}
.floating-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.card-kpi {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.kpi-num {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--brand-black);
}
.kpi-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}
.kpi-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--bg-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

/* ==========================================================================
   核心优势 (Core Features)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  transition: transform var(--transition-normal), border-color var(--transition-normal);
  display: flex;
  flex-direction: column;
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: #111111;
  box-shadow: var(--shadow-sm);
}

.feature-icon-box {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--bg-muted);
  border: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--brand-black);
}

.feature-title {
  font-family: var(--font-brand);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.feature-text {
  font-size: 0.94rem;
  color: var(--text-muted);
  line-height: 1.65;
  flex-grow: 1;
}

/* ==========================================================================
   流媒体与 AI 支持 (Streaming & AI)
   ========================================================================== */
.ecosystem-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.eco-block {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 36px 32px;
}

.eco-block-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}
.eco-block-header h3 {
  font-family: var(--font-brand);
  font-size: 1.35rem;
  font-weight: 700;
}

.eco-tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 20px;
}

.eco-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
}

.eco-disclaimer {
  font-size: 0.85rem;
  color: var(--text-muted);
  background: var(--bg-muted);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--brand-black);
  line-height: 1.6;
}

/* ==========================================================================
   套餐对比 (Pricing / Packages)
   ========================================================================== */
.pricing-notice {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 40px;
  background: var(--bg-subtle);
  border: 1px dashed var(--border-light);
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-muted);
}

.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-light);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}
.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.pricing-card.featured {
  border: 2px solid var(--brand-black);
  box-shadow: var(--shadow-md);
}

.featured-pill {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--brand-black);
  color: var(--brand-white);
  padding: 4px 16px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.pricing-plan-name {
  font-family: var(--font-brand);
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.pricing-plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  min-height: 42px;
}

.pricing-price-wrap {
  margin-bottom: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-light);
}
.pricing-status {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--brand-black);
}
.pricing-tip {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.pricing-features-list {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}
.pricing-features-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 12px;
  line-height: 1.5;
}
.pricing-features-list li svg {
  flex-shrink: 0;
  margin-top: 3px;
}

/* ==========================================================================
   常见问题 (FAQ Accordion)
   ========================================================================== */
.faq-wrap {
  max-width: 820px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border-light);
}
.faq-item:first-child {
  border-top: 1px solid var(--border-light);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 8px;
  font-family: var(--font-brand);
  font-size: 1.1rem;
  font-weight: 700;
  text-align: left;
  color: var(--text-main);
  transition: color var(--transition-fast);
}
.faq-question:hover {
  color: #000000;
}

.faq-chevron {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-normal);
  flex-shrink: 0;
}
.faq-item.is-open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal), opacity var(--transition-normal);
  opacity: 0;
}
.faq-item.is-open .faq-answer {
  max-height: 600px;
  opacity: 1;
}

.faq-answer-inner {
  padding: 0 8px 24px;
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.75;
}

/* ==========================================================================
   章节跳转侧边悬浮控制器 (Chapter Quick Nav)
   按页面章节顺序移动，支持首屏/页脚，边界禁用
   ========================================================================== */
.chapter-nav {
  position: fixed;
  right: 28px;
  bottom: 40px;
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  padding: 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-md);
}

.chapter-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--brand-white);
  border: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-main);
  transition: all var(--transition-fast);
}
.chapter-btn:hover:not(:disabled) {
  background: var(--brand-black);
  color: var(--brand-white);
  border-color: var(--brand-black);
}
.chapter-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

/* ==========================================================================
   文章与内容页样式 (Articles & Pages)
   ========================================================================== */
.article-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.article-header {
  margin-bottom: 40px;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 32px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 16px;
}

.article-title {
  font-family: var(--font-brand);
  font-size: 2.3rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--brand-black);
  margin-top: 12px;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #27272a;
}
.article-body h2 {
  font-family: var(--font-brand);
  font-size: 1.55rem;
  font-weight: 700;
  margin: 48px 0 20px;
  color: var(--brand-black);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 10px;
}
.article-body h3 {
  font-family: var(--font-brand);
  font-size: 1.25rem;
  font-weight: 700;
  margin: 32px 0 16px;
  color: var(--brand-black);
}
.article-body p {
  margin-bottom: 22px;
}
.article-body ul, .article-body ol {
  margin: 0 0 24px 28px;
}
.article-body li {
  margin-bottom: 10px;
}
.article-body blockquote {
  background: var(--bg-subtle);
  border-left: 4px solid var(--brand-black);
  padding: 16px 20px;
  margin: 28px 0;
  font-size: 0.98rem;
  color: var(--text-muted);
}
.article-body code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-muted);
  padding: 2px 6px;
  border-radius: 4px;
}
.article-body pre {
  background: var(--bg-dark);
  color: #f3f4f6;
  padding: 20px;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 24px 0;
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

/* 文章内置推广模块卡片 */
.article-promo-card {
  margin: 40px 0;
  background: var(--bg-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 30px;
  text-align: center;
}
.article-promo-card h4 {
  font-family: var(--font-brand);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 10px;
}
.article-promo-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  max-width: 600px;
  margin: 0 auto 20px;
}

/* ==========================================================================
   文章列表卡片网格 (Articles Grid)
   ========================================================================== */
.articles-catalog-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}
.article-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand-black);
}
.article-card-date {
  font-size: 0.82rem;
  color: var(--text-light);
  margin-bottom: 10px;
}
.article-card-title {
  font-family: var(--font-brand);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
}
.article-card-summary {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 20px;
}
.article-card-readmore {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--brand-black);
}

/* ==========================================================================
   全站页脚 (Footer)
   仅保留“网站地图”“关于我们”“服务条款”“隐私政策”四个入口，在新标签页打开
   ========================================================================== */
.site-footer {
  background: var(--bg-dark);
  color: #d1d5db;
  padding: 64px 0 36px;
  border-top: 1px solid var(--border-dark);
}

.footer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border-dark);
  margin-bottom: 32px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.footer-brand-title {
  font-family: var(--font-brand);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-white);
  letter-spacing: 0.05em;
}
.footer-brand-desc {
  font-size: 0.88rem;
  color: #9ca3af;
  max-width: 480px;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
}
.footer-nav a {
  font-size: 0.92rem;
  color: #e5e7eb;
  padding: 4px 0;
  transition: color var(--transition-fast);
}
.footer-nav a:hover {
  color: #ffffff;
  text-decoration: underline;
}

.footer-bottom {
  text-align: center;
  font-size: 0.85rem;
  color: #6b7280;
  line-height: 1.7;
}

/* ==========================================================================
   响应式媒体查询 (Responsive)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 60px 0;
  }
  .hero-title {
    font-size: 2.3rem;
  }
  .nav-desktop {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .ecosystem-grid {
    grid-template-columns: 1fr;
  }
  .articles-catalog-grid {
    grid-template-columns: 1fr;
  }
  .footer-top {
    flex-direction: column;
    align-items: flex-start;
    gap: 28px;
  }
  .footer-nav {
    flex-direction: column;
    gap: 14px;
  }
  .chapter-nav {
    right: 14px;
    bottom: 24px;
  }
  .chapter-btn {
    width: 40px;
    height: 40px;
  }
}