/* ==========================================================================
   Flybit 官方服务介绍站 - 核心样式表
   域名: guanwang.fly-bit.buzz
   极简、秒开、现代、移动端优先设计
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --accent: #10b981;
  --accent-light: #ecfdf5;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-alt: #f1f5f9;
  --border-color: #e2e8f0;
  --border-focus: #94a3b8;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 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);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --max-width: 1160px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

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

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  width: 100%;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* 导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  flex-shrink: 0;
  display: block;
}

.brand-badge {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.1rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.925rem;
  font-weight: 500;
  transition: color 0.15s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* 通用按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.55rem 1.25rem;
  font-size: 0.925rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.15s ease-in-out;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff !important;
  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.35);
}

.btn-secondary {
  background-color: #ffffff;
  color: var(--text-main) !important;
  border-color: var(--border-color);
}

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

.btn-accent {
  background-color: var(--accent);
  color: #ffffff !important;
}

.btn-accent:hover {
  background-color: #059669;
}

.btn-sm {
  padding: 0.35rem 0.85rem;
  font-size: 0.825rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.85rem 1.85rem;
  font-size: 1.05rem;
}

.btn-block {
  display: flex;
  width: 100%;
}

/* 紧凑精致现代化 Hero 首屏排版重构 (图文并茂) */
.hero {
  position: relative;
  padding: 2.75rem 0 2rem;
  background: 
    radial-gradient(100% 80% at 50% 0%, rgba(219, 234, 254, 0.7) 0%, rgba(248, 250, 252, 0.95) 75%),
    linear-gradient(180deg, #eff6ff 0%, #f8fafc 100%);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 1000px;
  height: 280px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 2.5rem;
  text-align: left;
}

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

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #ffffff;
  border: 1px solid rgba(37, 99, 235, 0.2);
  padding: 0.35rem 0.95rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.06);
  transition: transform 0.2s ease;
}

.hero-pill:hover {
  transform: translateY(-1px);
  border-color: rgba(37, 99, 235, 0.4);
}

.hero-pill-icon {
  width: 16px;
  height: 16px;
  border-radius: 4px;
}

.hero-pill-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
}

.hero-pill-text {
  font-size: 0.825rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.02em;
}

.hero h1 {
  font-size: 2.25rem;
  line-height: 1.25;
  font-weight: 900;
  color: var(--text-main);
  letter-spacing: -0.03em;
  margin-bottom: 0.85rem;
}

.hero h1 .text-gradient {
  background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 50%, #0284c7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.hero-desc {
  font-size: 1.025rem;
  line-height: 1.65;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1rem;
}

.btn-hero-primary {
  padding: 0.85rem 2rem;
  font-size: 1.05rem;
  font-weight: 700;
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  color: #ffffff !important;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
  transition: all 0.2s ease;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-hero-primary:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
}

.btn-hero-primary svg {
  transition: transform 0.15s ease;
}

.btn-hero-primary:hover svg {
  transform: translateX(3px);
}

.hero-tips {
  font-size: 0.8rem;
  color: var(--text-light);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Hero 图案视觉卡片 */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-visual-card {
  position: relative;
  width: 100%;
  max-width: 360px;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(241, 245, 249, 0.85) 100%);
  border: 1px solid rgba(203, 213, 225, 0.8);
  border-radius: var(--radius-lg);
  padding: 1.75rem 1.5rem;
  box-shadow: 0 16px 36px -8px rgba(37, 99, 235, 0.14), 0 4px 12px rgba(0, 0, 0, 0.04);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hero-graphic-wrap {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 0;
}

.hero-graphic-img {
  width: 140px;
  height: 140px;
  border-radius: 28px;
  object-fit: cover;
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.28);
  border: 3px solid #ffffff;
  transition: transform 0.3s ease;
}

.hero-graphic-wrap:hover .hero-graphic-img {
  transform: scale(1.04) rotate(-1deg);
}

.hero-float-badge {
  position: absolute;
  background: #ffffff;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.775rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  white-space: nowrap;
}

.hero-float-badge.badge-top {
  top: -5px;
  right: -5px;
  color: #1d4ed8;
}

.hero-float-badge.badge-bottom {
  bottom: -5px;
  left: -5px;
  color: var(--accent);
}

.hero-float-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.hero-visual-footer {
  margin-top: 1.15rem;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-around;
  font-size: 0.75rem;
  color: var(--text-light);
  font-weight: 600;
}

/* 核心板块通用 */
.section {
  padding: 3.5rem 0;
}

.section-alt {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 2.5rem auto;
}

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

.section-title {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

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

/* 套餐价格表 (同排显示) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: #cbd5e1;
}

.pricing-card.featured {
  border: 2px solid var(--primary);
  box-shadow: 0 8px 24px -4px rgba(37, 99, 235, 0.15);
}

.card-badge-hot {
  position: absolute;
  top: -12px;
  right: 1.5rem;
  background: var(--primary);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.pricing-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.35rem;
}

.pricing-desc {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 1.25rem;
  min-height: 2.4em;
}

.pricing-price-wrap {
  margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

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

.pricing-amount {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.pricing-cycle {
  font-size: 0.85rem;
  color: var(--text-light);
}

.pricing-equiv {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  margin-top: 0.35rem;
}

.pricing-features {
  list-style: none;
  margin-bottom: 1.75rem;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pricing-features li svg {
  flex-shrink: 0;
  color: var(--accent);
}

.pricing-notice {
  text-align: center;
  font-size: 0.825rem;
  color: var(--text-light);
  margin-top: 1.5rem;
}

/* 核心优势卡片 (3个图文卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: all 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-2px);
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.feature-icon-box {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.feature-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 流媒体与 AI 支持图卡 */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.media-ai-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.media-ai-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.media-ai-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--bg-card-alt);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

/* 内容导航与专题页面卡片 */
.topics-nav-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.topic-item-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  text-decoration: none;
  color: inherit;
  transition: all 0.2s ease;
  display: block;
}

.topic-item-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.topic-item-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.topic-item-card p {
  font-size: 0.825rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* 深度文章卡片网格 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: all 0.2s ease;
}

.article-card:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.article-meta {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-bottom: 0.5rem;
  display: flex;
  gap: 0.75rem;
}

.article-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.65rem;
}

.article-card h3 a {
  text-decoration: none;
  color: var(--text-main);
  transition: color 0.15s ease;
}

.article-card h3 a:hover {
  color: var(--primary);
}

.article-excerpt {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

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

.article-readmore {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  text-decoration: none;
}

.article-readmore:hover {
  text-decoration: underline;
}

/* FAQ 常见问题解答 */
.faq-grid {
  max-width: 820px;
  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);
  padding: 1.25rem 1.5rem;
}

.faq-item h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.faq-item p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 用户评价 */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.testimonial-text {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1.25rem;
  font-style: italic;
}

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

.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.author-info h5 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-main);
}

.author-info span {
  font-size: 0.775rem;
  color: var(--text-light);
}

/* 底部 CTA 板块 */
.cta-banner {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  color: #ffffff;
  padding: 4rem 0;
  text-align: center;
}

.cta-banner h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.cta-banner p {
  font-size: 1rem;
  color: #94a3b8;
  max-width: 600px;
  margin: 0 auto 1.75rem auto;
}

/* 页脚 Footer (规范：只保留这四个标题) */
.footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 3rem 0 2rem;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
  margin-bottom: 1.5rem;
}

.footer-nav a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  transition: color 0.15s ease;
}

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

.footer-copy {
  text-align: center;
  font-size: 0.825rem;
  color: var(--text-light);
}

/* ==========================================================================
   文章页与内页专属样式
   ========================================================================== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-light);
  padding: 1.25rem 0;
  list-style: none;
}

.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
}

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

.breadcrumb-sep {
  color: #cbd5e1;
}

.page-header {
  padding: 2.5rem 0 2rem;
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2.15rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.85rem;
  color: var(--text-light);
}

.article-container {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 2.5rem;
  padding: 2.5rem 0;
}

.article-content {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
}

.lead-box {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 2rem;
  font-size: 0.95rem;
  color: #1e3a8a;
  line-height: 1.7;
}

.article-cta-box {
  background: #f8fafc;
  border: 1px dashed var(--primary);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin: 2rem 0;
}

.article-body h2 {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 1.5rem 0 0.75rem;
}

.article-body p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 1.25rem;
}

.article-body ul, .article-body ol {
  margin: 0 0 1.25rem 1.5rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.75;
}

/* 正文内部链接样式强化 (SEO友好与视觉辨识) */
.article-body a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 500;
  transition: all 0.15s ease;
}

.article-body a:hover {
  color: var(--primary-hover);
  background-color: var(--primary-light);
  border-radius: 2px;
  text-decoration-thickness: 2px;
}

/* 上一篇 / 下一篇 导航条 */
.post-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin: 2.5rem 0 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

.post-nav-card {
  display: flex;
  flex-direction: column;
  padding: 1rem 1.25rem;
  background-color: var(--bg-card-alt);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.2s ease;
}

.post-nav-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  background-color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.post-nav-card.next {
  text-align: right;
}

.post-nav-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-light);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.post-nav-card.next .post-nav-label {
  justify-content: flex-end;
}

.post-nav-title {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.4;
}

/* 文末相关阅读矩阵卡片 */
.related-posts-section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 2px dashed var(--border-color);
}

.related-posts-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.related-card {
  background: var(--bg-card-alt);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.15rem;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s ease;
}

.related-card:hover {
  background: #ffffff;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.related-card-tag {
  font-size: 0.725rem;
  color: var(--primary);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.related-card-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 0.5rem;
}

.related-card-more {
  font-size: 0.775rem;
  font-weight: 600;
  color: var(--text-light);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

@media (max-width: 768px) {
  .post-pagination,
  .related-posts-grid {
    grid-template-columns: 1fr;
  }
  .post-nav-card.next {
    text-align: left;
  }
  .post-nav-card.next .post-nav-label {
    justify-content: flex-start;
  }
}


.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.875rem;
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.article-body th, .article-body td {
  border: 1px solid var(--border-color);
  padding: 0.65rem 0.85rem;
  text-align: left;
  white-space: nowrap;
}

.article-body th {
  background-color: var(--bg-card-alt);
  font-weight: 700;
  color: var(--text-main);
}

.keyword-tag {
  display: inline-block;
  background: var(--bg-card-alt);
  color: var(--text-muted);
  font-size: 0.75rem;
  padding: 2px 6px;
  border-radius: 4px;
  margin: 0 2px;
}

/* 侧边栏 Widget */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.widget {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.widget-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.widget-list {
  list-style: none;
}

.widget-list li {
  margin-bottom: 0.75rem;
}

.widget-list a {
  text-decoration: none;
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.5;
  display: block;
}

.widget-list a:hover {
  color: var(--primary);
}

/* ==========================================================================
   全方位移动端深度优化与响应式断点 (Mobile First System)
   ========================================================================== */

/* 平板 / 小屏笔记本断点 (<= 992px) */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2rem;
  }

  .hero-content {
    align-items: center;
  }

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

  .hero-visual {
    margin-top: 0.5rem;
  }

  .hero-graphic-img {
    width: 130px;
    height: 130px;
  }

  .pricing-grid,
  .features-grid,
  .articles-grid,
  .topics-nav-grid,
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .article-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

/* 核心主流手机端适配 (<= 768px) */
@media (max-width: 768px) {
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  /* 移动端 App-like 原生横滑胶囊导航条 */
  .header {
    padding-bottom: 0.25rem;
  }

  .nav-wrap {
    flex-wrap: wrap;
    height: auto;
    padding-top: 0.65rem;
    padding-bottom: 0.25rem;
  }

  .nav-links {
    display: flex !important;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding: 0.45rem 0 0.25rem;
    gap: 0.5rem;
    scrollbar-width: none;
  }

  .nav-links::-webkit-scrollbar {
    display: none;
  }

  .nav-links li {
    flex-shrink: 0;
  }

  .nav-links a {
    display: inline-block;
    padding: 0.25rem 0.7rem;
    background: var(--bg-card-alt);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    white-space: nowrap;
    color: var(--text-muted);
  }

  .nav-links a.active {
    background: var(--primary);
    border-color: var(--primary);
    color: #ffffff !important;
  }

  /* Hero 手机端紧凑视觉与防溢出 */
  .hero {
    padding: 2.25rem 0 1.75rem;
  }

  .hero h1 {
    font-size: 1.75rem;
    line-height: 1.3;
  }

  .hero-desc {
    font-size: 0.95rem;
    margin-bottom: 1.25rem;
  }

  .hero-visual-card {
    max-width: 100%;
    padding: 1.25rem 1rem;
  }

  .hero-graphic-img {
    width: 110px;
    height: 110px;
    border-radius: 22px;
  }

  .hero-float-badge.badge-top {
    right: 2px;
    top: -2px;
  }

  .hero-float-badge.badge-bottom {
    left: 2px;
    bottom: -2px;
  }

  .btn-hero-primary {
    width: 100%;
    max-width: 320px;
    justify-content: center;
  }

  /* 核心网格移动端全面单列堆叠 */
  .pricing-grid,
  .features-grid,
  .media-ai-grid,
  .articles-grid,
  .topics-nav-grid,
  .testimonials-grid,
  .related-posts-grid,
  .post-pagination {
    grid-template-columns: 1fr;
    gap: 1.15rem;
  }

  .section {
    padding: 2.5rem 0;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .article-content {
    padding: 1.25rem;
    border-radius: var(--radius-md);
  }

  .page-title {
    font-size: 1.65rem;
  }

  .article-body h2 {
    font-size: 1.25rem;
  }

  .article-body h3 {
    font-size: 1.1rem;
  }

  .article-cta-box {
    flex-direction: column;
    text-align: center;
    padding: 1rem;
  }

  .footer-nav {
    flex-wrap: wrap;
    gap: 1rem 1.5rem;
    justify-content: center;
  }

  .post-nav-card.next {
    text-align: left;
  }

  .post-nav-card.next .post-nav-label {
    justify-content: flex-start;
  }
}

/* 超窄屏手机专属防溢出微调 (<= 480px) */
@media (max-width: 480px) {
  .hero-pill {
    padding: 0.3rem 0.75rem;
  }

  .hero-pill-text {
    font-size: 0.75rem;
  }

  .hero h1 {
    font-size: 1.55rem;
  }

  .hero-tips {
    font-size: 0.725rem;
    flex-wrap: wrap;
  }

  .pricing-card {
    padding: 1.5rem 1.15rem;
  }

  .pricing-amount {
    font-size: 2rem;
  }

  .cta-banner h2 {
    font-size: 1.5rem;
  }

  .cta-banner {
    padding: 2.75rem 0;
  }
}