/* 肥猫云机场 (FatCat Cloud Airport) - 纯白极致简约 + 流光动态特效 CSS */

:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent-primary: #2563eb;
  --accent-light: #60a5fa;
  --accent-glow: rgba(37, 99, 235, 0.15);
  
  /* 流光渐变色配置 */
  --glow-gradient: linear-gradient(135deg, #3b82f6, #8b5cf6, #ec4899, #3b82f6);
  --glow-subtle: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(139, 92, 246, 0.08));
  --glow-border: linear-gradient(90deg, #3b82f6, #a855f7, #ec4899, #3b82f6);
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.06), 0 2px 6px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 24px -4px rgba(0, 0, 0, 0.08), 0 4px 12px -2px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.18);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --container-width: 1200px;
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  scroll-behavior: smooth;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
}

/* 全局背景微光流动效果 */
body::before {
  content: "";
  position: fixed;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.05) 0%, rgba(139, 92, 246, 0.03) 40%, rgba(255, 255, 255, 0) 70%);
  pointer-events: none;
  z-index: 0;
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* 顶部导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition-normal);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--glow-gradient);
  background-size: 300% 300%;
  animation: streamGlow 6s ease infinite;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.25rem;
  box-shadow: var(--shadow-sm);
}

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

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

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--glow-gradient);
  transition: var(--transition-fast);
  border-radius: 2px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: var(--transition-normal);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

/* 流光微光按钮 */
.btn-primary {
  background: #0f172a;
  color: #ffffff;
  position: relative;
  overflow: hidden;
  z-index: 1;
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.15);
}

.btn-primary::before {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  background: var(--glow-gradient);
  background-size: 300% 300%;
  animation: streamGlow 4s ease infinite;
  z-index: -1;
  border-radius: var(--radius-full);
  opacity: 0;
  transition: var(--transition-normal);
}

.btn-primary:hover::before {
  opacity: 1;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border-color: var(--border-color);
}

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

.btn-glow {
  background: var(--glow-gradient);
  background-size: 300% 300%;
  animation: streamGlow 6s ease infinite;
  color: #ffffff;
  box-shadow: 0 4px 15px rgba(59, 130, 246, 0.35);
}

.btn-glow:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(139, 92, 246, 0.45);
}

/* 移动端菜单按钮 */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-primary);
  cursor: pointer;
}

/* 动画流光关键帧 */
@keyframes streamGlow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes floatAnim {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-8px); }
}

@keyframes pulseGlow {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.8; }
}

/* 通用章节规范 */
.section {
  padding: 5rem 0;
  position: relative;
}

.section-bg {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem auto;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 1rem;
  background: var(--glow-subtle);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-primary);
  margin-bottom: 1rem;
}

.badge-dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-primary);
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

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

/* 首页 Hero 区域 */
.hero {
  padding: 6rem 0 4rem 0;
  text-align: center;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.hero-title-gradient {
  background: var(--glow-gradient);
  background-size: 200% 200%;
  animation: streamGlow 5s ease infinite;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 780px;
  margin: 0 auto 2.5rem auto;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 3.5rem;
  flex-wrap: wrap;
}

.hero-features-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  flex-wrap: wrap;
  padding: 1.25rem 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  max-width: 900px;
  margin: 0 auto;
}

.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.hero-feature-icon {
  color: var(--accent-primary);
  font-size: 1.1rem;
}

/* 卡片标准样式 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

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

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--glow-gradient);
  background-size: 200% 200%;
  opacity: 0;
  transition: var(--transition-normal);
}

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

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

/* 核心优势卡片 */
.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: var(--glow-subtle);
  border: 1px solid rgba(59, 130, 246, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--accent-primary);
  margin-bottom: 1.25rem;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* 套餐价格区域 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem;
  transition: var(--transition-normal);
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-card.featured {
  border-color: #3b82f6;
  box-shadow: var(--shadow-glow);
}

.pricing-card.featured::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--glow-gradient);
  background-size: 300% 300%;
  animation: streamGlow 4s ease infinite;
}

.pricing-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: var(--glow-gradient);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
}

.pricing-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.pricing-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-muted);
}

.pricing-list {
  list-style: none;
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.pricing-item-icon {
  color: #10b981;
  font-size: 1rem;
}

/* 适合人群区域 */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.audience-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  transition: var(--transition-fast);
}

.audience-card:hover {
  background: var(--bg-secondary);
  border-color: var(--border-hover);
}

.audience-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--glow-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-primary);
  font-size: 1.3rem;
  flex-shrink: 0;
}

.audience-info h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.audience-info p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* 教程区域 Tab 切换 */
.tutorial-tabs {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition-fast);
}

.tab-btn:hover, .tab-btn.active {
  background: #0f172a;
  color: #ffffff;
  border-color: #0f172a;
  box-shadow: var(--shadow-sm);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.tutorial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
}

.tutorial-step-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 1.5rem;
}

.step-item {
  position: relative;
  padding-left: 3.5rem;
}

.step-num {
  position: absolute;
  left: 0;
  top: 0;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--glow-subtle);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 50%;
  color: var(--accent-primary);
  font-weight: 800;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.step-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 用户评价 */
.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.testimonial-stars {
  color: #f59e0b;
  font-size: 1rem;
  margin-bottom: 1rem;
}

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

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.avatar-placeholder {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--glow-gradient);
  color: #fff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.author-name {
  font-weight: 700;
  font-size: 0.95rem;
}

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

/* FAQ 手风琴 */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

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

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

.faq-question {
  width: 100%;
  padding: 1.25rem 1.5rem;
  background: none;
  border: none;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-icon {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--accent-primary);
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 1.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 1.5rem 1.5rem 1.5rem;
}

/* 文章推荐与目录列表 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: var(--transition-normal);
}

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

.article-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.article-card-title {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.article-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

/* 文章详情页样式 */
.article-header {
  padding: 4rem 0 2rem 0;
  text-align: center;
  max-width: 840px;
  margin: 0 auto;
}

.breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

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

.article-main-title {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.article-post-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.article-body {
  max-width: 820px;
  margin: 0 auto 5rem auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: var(--shadow-sm);
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 800;
  margin: 2.25rem 0 1rem 0;
  color: var(--text-primary);
  border-left: 4px solid var(--accent-primary);
  padding-left: 0.75rem;
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 1.75rem 0 0.75rem 0;
  color: var(--text-primary);
}

.article-body p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.article-body ul, .article-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body blockquote {
  background: var(--glow-subtle);
  border-left: 4px solid var(--accent-primary);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.75rem 0;
  font-size: 1rem;
  color: var(--text-primary);
  font-style: italic;
}

.article-cta-box {
  background: linear-gradient(135deg, #0f172a, #1e293b);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  color: #ffffff;
  text-align: center;
  margin: 3rem 0;
}

.article-cta-box h3 {
  color: #ffffff;
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.article-cta-box p {
  color: #94a3b8;
  margin-bottom: 1.5rem;
}

/* 页脚 Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem 0;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.footer-brand p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-top: 1rem;
  max-width: 320px;
}

.footer-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition-fast);
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.88rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 1rem;
}

/* 响应式调整 */
@media (max-width: 992px) {
  .hero-title { font-size: 2.5rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #ffffff;
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
    flex-direction: column;
    align-items: stretch;
    box-shadow: var(--shadow-md);
  }
  .nav-links.active { display: flex; }
  .mobile-toggle { display: block; }
  .hero-title { font-size: 2.1rem; }
  .hero-desc { font-size: 1rem; }
  .section-title { font-size: 1.75rem; }
  .article-body { padding: 1.5rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
}