/* ==========================================================================
   贝贝云 (beibeiyun.link) - 全局原生 CSS 样式表 (视觉与交互深度优化版)
   无外部字体、无臃肿框架、秒开加载、高无障碍性与全面响应式适配
   ========================================================================== */

:root {
  /* 基础底色与层次：深邃现代暗色科技体系 */
  --bg-primary: #070b16;
  --bg-secondary: #0c1222;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(22, 34, 62, 0.88);
  --bg-glass: rgba(15, 23, 42, 0.65);
  
  /* 边框与光影线 */
  --border-color: rgba(56, 189, 248, 0.14);
  --border-hover: rgba(56, 189, 248, 0.35);
  --border-accent: rgba(0, 229, 255, 0.45);
  --border-highlight: rgba(255, 255, 255, 0.12);
  
  /* 文字与排版对比度 (确保普通文本 >= 4.5:1) */
  --text-main: #f8fafc;
  --text-light: #cbd5e1;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  /* 品牌核心色与渐变 */
  --color-primary: #00e5ff;
  --color-primary-rgb: 0, 229, 255;
  --color-secondary: #3b82f6;
  --color-accent: #38bdf8;
  --color-gold: #f59e0b;
  --color-success: #10b981;
  --color-tag: rgba(0, 229, 255, 0.1);

  --color-gradient: linear-gradient(135deg, #00e5ff 0%, #2563eb 100%);
  --color-gradient-hover: linear-gradient(135deg, #38bdf8 0%, #1d4ed8 100%);
  --color-btn-hover: linear-gradient(135deg, #22d3ee 0%, #3b82f6 100%);
  --color-card-border: linear-gradient(135deg, rgba(56, 189, 248, 0.3) 0%, rgba(37, 99, 235, 0.1) 100%);

  /* 光影与景深系统 */
  --shadow-sm: 0 4px 16px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 30px -5px rgba(0, 0, 0, 0.5), 0 0 1px 1px rgba(255, 255, 255, 0.05);
  --shadow-lg: 0 20px 40px -10px rgba(0, 0, 0, 0.65), 0 0 20px rgba(0, 229, 255, 0.15);
  --shadow-glow: 0 0 28px rgba(0, 229, 255, 0.25);
  --shadow-glow-strong: 0 0 40px rgba(0, 229, 255, 0.4);

  /* 圆角与度量体系 */
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --container-width: 1180px;
  --header-height: 72px;
}

/* ==========================================================================
   全局重置与平滑滚动
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.7;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background: 
    radial-gradient(circle at 85% 10%, rgba(37, 99, 235, 0.18) 0%, transparent 45%),
    radial-gradient(circle at 15% 45%, rgba(0, 229, 255, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 70% 85%, rgba(56, 189, 248, 0.08) 0%, transparent 45%),
    var(--bg-primary);
  position: relative;
}

/* 微妙科技网格底层背景 */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(rgba(56, 189, 248, 0.08) 1px, transparent 1px);
  background-size: 36px 36px;
  pointer-events: none;
  z-index: -1;
  mask-image: radial-gradient(ellipse at 50% 25%, black 40%, transparent 85%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 25%, black 40%, transparent 85%);
}

/* 无障碍跳过导航 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--color-primary);
  color: #030712;
  padding: 12px 22px;
  z-index: 9999;
  border-radius: var(--radius-sm);
  font-weight: 800;
  font-size: 0.95rem;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0, 229, 255, 0.6);
  transition: top 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.skip-link:focus {
  top: 20px;
  outline: 3px solid #ffffff;
  outline-offset: 2px;
}

/* 版心容器 */
.container {
  width: min(var(--container-width), calc(100% - 40px));
  margin-inline: auto;
}

/* ==========================================================================
   顶部导航栏 (Glassmorphism 磨砂微光质感)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(7, 11, 22, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  transition: background 0.3s, border-color 0.3s, box-shadow 0.3s;
}

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

/* 品牌 Logo */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  position: relative;
  transition: opacity 0.2s, transform 0.2s;
}

.brand-logo:hover {
  opacity: 0.98;
  transform: translateY(-1px);
}

.brand-logo-img {
  width: 38px;
  height: 38px;
  object-fit: contain;
  display: block;
  flex-shrink: 0;
  filter: drop-shadow(0 2px 8px rgba(245, 158, 11, 0.4)) drop-shadow(0 0 16px rgba(0, 229, 255, 0.35));
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), filter 0.3s ease;
  user-select: none;
}

.brand-logo:hover .brand-logo-img {
  transform: scale(1.12) rotate(-4deg);
  filter: drop-shadow(0 4px 14px rgba(245, 158, 11, 0.6)) drop-shadow(0 0 24px rgba(0, 229, 255, 0.55));
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--color-gradient);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #030712;
  box-shadow: 0 0 16px rgba(0, 229, 255, 0.45);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
  transition: box-shadow 0.3s ease, transform 0.3s ease;
}

.brand-logo:hover .brand-icon {
  box-shadow: 0 0 24px rgba(0, 229, 255, 0.7);
}

.brand-icon img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  display: block;
}

.brand-shell-svg {
  width: 22px;
  height: 22px;
  display: block;
  color: #040814;
  position: relative;
  z-index: 1;
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), filter 0.3s ease;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.25));
}

.brand-logo:hover .brand-shell-svg {
  transform: scale(1.1) rotate(-4deg);
  filter: drop-shadow(0 2px 5px rgba(0, 0, 0, 0.4));
}

.brand-icon::after {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 50%;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.4) 0%, transparent 100%);
  border-radius: 10px 10px 0 0;
  pointer-events: none;
}

/* 导航链接 */
.main-nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.main-nav a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.94rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  position: relative;
}

.main-nav a:hover, 
.main-nav a:focus-visible {
  color: var(--color-primary);
  background-color: rgba(56, 189, 248, 0.1);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px !important;
  background: var(--color-gradient) !important;
  color: #030712 !important;
  font-weight: 800 !important;
  font-size: 0.92rem !important;
  border-radius: var(--radius-full) !important;
  box-shadow: 0 4px 18px rgba(0, 229, 255, 0.35);
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s ease !important;
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 229, 255, 0.55) !important;
}

/* ==========================================================================
   主视觉区 (Hero Section) - 极速动能氛围
   ========================================================================== */
.hero-section {
  padding: 96px 0 72px;
  text-align: center;
  position: relative;
}

/* 发光胶囊标签 */
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(0, 229, 255, 0.08);
  border: 1px solid var(--border-accent);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 28px;
  box-shadow: 0 0 20px rgba(0, 229, 255, 0.15), inset 0 1px 0 rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: clamp(2.3rem, 5.2vw, 3.8rem);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -1px;
  margin-bottom: 22px;
  background: linear-gradient(180deg, #ffffff 25%, #cbd5e1 70%, #7dd3fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 4px 16px rgba(0, 0, 0, 0.4));
}

.hero-subtitle {
  font-size: clamp(1.15rem, 2.4vw, 1.45rem);
  color: var(--color-primary);
  font-weight: 600;
  letter-spacing: 0.2px;
  margin-bottom: 18px;
  text-shadow: 0 0 20px rgba(0, 229, 255, 0.25);
}

.hero-desc {
  max-width: 820px;
  margin: 0 auto 40px;
  color: var(--text-muted);
  font-size: 1.08rem;
  line-height: 1.8;
}

/* 按钮组与按钮核心规范 (满足 >= 44x44px 触控标准) */
.cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 52px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 32px;
  font-size: 1.02rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  border: none;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--color-gradient);
  color: #030712;
  box-shadow: 0 6px 24px rgba(0, 229, 255, 0.38), inset 0 1px 1px rgba(255, 255, 255, 0.4);
}

.btn-primary:hover {
  background: var(--color-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(0, 229, 255, 0.55), inset 0 1px 1px rgba(255, 255, 255, 0.6);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-main);
  border: 1px solid var(--border-hover);
  backdrop-filter: blur(8px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.btn-secondary:hover {
  background: rgba(56, 189, 248, 0.12);
  border-color: var(--color-primary);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 229, 255, 0.2);
}

/* ==========================================================================
   区块通用骨架
   ========================================================================= */
.section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 52px;
}

.section-tag {
  color: var(--color-primary);
  font-size: 0.88rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
  display: inline-block;
}

.section-title {
  font-size: clamp(1.9rem, 3.6vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  color: #ffffff;
  margin-bottom: 16px;
}

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

/* ==========================================================================
   产品核心优势 (3个图文卡片)
   ========================================================================== */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 28px;
  box-shadow: var(--shadow-md);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), 
              border-color 0.3s ease, 
              box-shadow 0.3s ease,
              background-color 0.3s ease;
  backdrop-filter: blur(12px);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.3), transparent);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-accent);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  background: var(--bg-card-hover);
}

.card-icon {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(0, 229, 255, 0.15) 0%, rgba(37, 99, 235, 0.1) 100%);
  border: 1px solid var(--border-accent);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.65rem;
  margin-bottom: 24px;
  box-shadow: 0 4px 16px rgba(0, 229, 255, 0.15);
}

.feature-card h3 {
  font-size: 1.32rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 14px;
  letter-spacing: -0.2px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.72;
}

/* ==========================================================================
   流媒体与 AI 支持图卡
   ========================================================================== */
.media-ai-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  margin-top: 24px;
}

.media-ai-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 40px 34px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(12px);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

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

.media-ai-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: var(--color-gradient);
}

.media-ai-card h3 {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 14px;
  color: #ffffff;
}

.media-ai-card p {
  color: var(--text-muted);
  font-size: 1.02rem;
  margin-bottom: 26px;
  line-height: 1.7;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.service-tag {
  padding: 7px 16px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  color: var(--text-light);
  font-weight: 500;
  transition: all 0.2s ease;
}

.service-tag:hover {
  color: var(--color-primary);
  background: rgba(0, 229, 255, 0.1);
  border-color: var(--border-accent);
  transform: translateY(-1px);
}

/* ==========================================================================
   套餐价格对比表 (专业 SaaS 级数据表体验)
   ========================================================================== */
.pricing-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  box-shadow: var(--shadow-lg);
  margin-top: 32px;
  backdrop-filter: blur(14px);
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 720px;
}

.pricing-table caption {
  caption-side: top;
  text-align: left;
  padding: 18px 28px;
  font-size: 0.94rem;
  font-weight: 500;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
  background: rgba(12, 18, 34, 0.85);
}

.pricing-table th, 
.pricing-table td {
  padding: 22px 28px;
  border-bottom: 1px solid var(--border-color);
  vertical-align: middle;
}

.pricing-table thead th {
  background: rgba(10, 15, 30, 0.95);
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.3px;
}

.pricing-table tbody tr {
  transition: background-color 0.2s ease;
}

.pricing-table tbody tr:hover {
  background: rgba(56, 189, 248, 0.04);
}

.pricing-table .plan-name {
  font-weight: 800;
  font-size: 1.12rem;
  color: #ffffff;
  display: block;
}

.pricing-table .plan-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--radius-xs);
  font-size: 0.76rem;
  font-weight: 700;
  background: var(--color-tag);
  color: var(--color-primary);
  border: 1px solid rgba(0, 229, 255, 0.25);
  margin-top: 6px;
}

.pricing-table .price {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--color-primary);
  letter-spacing: -0.5px;
}

.pricing-table .period {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ==========================================================================
   用户口碑评价 (精选信赖卡片)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 26px;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
  display: flex;
  flex-direction: column;
}

.review-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.review-stars {
  color: var(--color-gold);
  margin-bottom: 14px;
  font-size: 1.15rem;
  letter-spacing: 3px;
  text-shadow: 0 0 10px rgba(245, 158, 11, 0.4);
}

.review-text {
  font-size: 0.98rem;
  color: var(--text-light);
  margin-bottom: 20px;
  line-height: 1.75;
  flex-grow: 1;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(0, 229, 255, 0.2) 0%, rgba(37, 99, 235, 0.2) 100%);
  border: 1px solid var(--border-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--color-primary);
  box-shadow: 0 2px 10px rgba(0, 229, 255, 0.2);
}

.author-info strong {
  display: block;
  font-size: 0.94rem;
  color: #ffffff;
  margin-bottom: 2px;
}

.author-info span {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ==========================================================================
   FAQ 常见问题解答 (原生 details/summary 现代化手风琴)
   ========================================================================== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 900px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
  transition: all 0.25s ease;
}

.faq-item[open] {
  border-color: var(--border-accent);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35), 0 0 16px rgba(0, 229, 255, 0.12);
}

.faq-item summary {
  padding: 22px 28px;
  font-weight: 700;
  font-size: 1.08rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.02);
  user-select: none;
  transition: background-color 0.2s, color 0.2s;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary:hover {
  color: var(--color-primary);
  background: rgba(56, 189, 248, 0.05);
}

.faq-item summary::after {
  content: "▾";
  font-size: 1.3rem;
  color: var(--color-primary);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  display: inline-block;
  margin-left: 14px;
}

.faq-item[open] summary::after {
  transform: rotate(180deg);
}

.faq-content {
  padding: 18px 28px 28px;
  color: var(--text-light);
  font-size: 1rem;
  line-height: 1.78;
  border-top: 1px solid var(--border-color);
  background: rgba(0, 0, 0, 0.15);
}

.faq-content a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 4px;
  font-weight: 600;
  transition: color 0.2s;
}

.faq-content a:hover {
  color: #ffffff;
}

/* ==========================================================================
   页脚 Footer (极简严谨四列规范)
   ========================================================================== */
.site-footer {
  margin-top: auto;
  background: #040812;
  border-top: 1px solid var(--border-color);
  padding: 56px 0 36px;
  position: relative;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.25), transparent);
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  flex-wrap: wrap;
  margin-bottom: 26px;
}

.footer-nav a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.96rem;
  font-weight: 500;
  transition: all 0.2s ease;
  padding: 4px 8px;
}

.footer-nav a:hover, 
.footer-nav a:focus-visible {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer-copy {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
  line-height: 1.6;
}

/* ==========================================================================
   文章详情页与独立页面专用样式 (优雅排版规范)
   ========================================================================== */
.article-header {
  padding: 56px 0 28px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 40px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

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

.article-title {
  font-size: clamp(1.9rem, 4vw, 2.7rem);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.5px;
  margin-bottom: 18px;
  color: #ffffff;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 24px;
  color: var(--text-muted);
  font-size: 0.88rem;
  flex-wrap: wrap;
}

.article-body {
  max-width: 860px;
  margin: 0 auto;
  font-size: 1.05rem;
  line-height: 1.88;
  color: #e2e8f0;
}

.article-body h2 {
  font-size: 1.55rem;
  font-weight: 800;
  margin: 44px 0 18px;
  color: #ffffff;
  border-left: 4px solid var(--color-primary);
  padding-left: 16px;
  letter-spacing: -0.2px;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 28px 0 14px;
  color: #f1f5f9;
}

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

.article-body ul, 
.article-body ol {
  margin: 0 0 24px 28px;
  color: var(--text-light);
}

.article-body li {
  margin-bottom: 10px;
  padding-left: 4px;
}

.article-body a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 4px;
  font-weight: 600;
  transition: color 0.2s;
}

.article-body a:hover {
  color: #ffffff;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.95) 0%, rgba(12, 18, 34, 0.9) 100%);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 40px 32px;
  text-align: center;
  margin: 54px 0;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.article-cta-box::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: var(--color-gradient);
}

.article-cta-box h3 {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 14px;
  color: #ffffff;
}

.article-cta-box p {
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 24px;
  font-size: 1.02rem;
}

/* ==========================================================================
   知识库列表卡片 (knowledge.html)
   ========================================================================== */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 40px;
}

.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.25s, box-shadow 0.25s;
}

.knowledge-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-accent);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.knowledge-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
}

.knowledge-card h3 a {
  color: #ffffff;
  text-decoration: none;
  transition: color 0.2s;
}

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

.knowledge-card p {
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.65;
  flex-grow: 1;
  margin-bottom: 20px;
}

.knowledge-card .read-more {
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.2s ease;
}

.knowledge-card .read-more:hover {
  gap: 10px;
  color: #ffffff;
}

/* ==========================================================================
   无障碍焦点与平滑过渡
   ========================================================================== */
a:focus-visible, 
button:focus-visible, 
summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
  border-radius: var(--radius-xs);
}

/* 动效适配尊重用户操作系统设置 */
@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;
  }
}

/* ==========================================================================
   全面响应式断点适配 (@media)
   ========================================================================== */

/* 平板端 (小于 1024px) */
@media (max-width: 1024px) {
  .grid-3, 
  .reviews-grid, 
  .knowledge-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 22px;
  }

  .media-ai-container {
    gap: 22px;
  }
}

/* 移动端 (小于 768px) - 完美单栏极简体验，按钮完全适合手指点击 */
@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .site-header .container {
    flex-wrap: wrap;
    gap: 12px;
  }

  .main-nav {
    gap: 8px;
    flex-wrap: wrap;
  }

  .main-nav a {
    padding: 6px 10px;
    font-size: 0.88rem;
  }

  .nav-cta {
    min-height: 40px;
    padding: 0 16px !important;
    font-size: 0.86rem !important;
  }

  .hero-section {
    padding: 56px 0 40px;
  }

  .cta-group {
    flex-direction: column;
    width: 100%;
    gap: 14px;
  }

  .cta-group .btn {
    width: 100%;
    max-width: 340px;
  }

  .grid-3, 
  .media-ai-container, 
  .reviews-grid, 
  .knowledge-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .feature-card, 
  .media-ai-card, 
  .review-card, 
  .knowledge-card {
    padding: 26px 20px;
  }

  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }

  .pricing-table th, 
  .pricing-table td {
    padding: 16px 18px;
  }
}

/* 超窄屏手机 (小于 390px) */
@media (max-width: 390px) {
  .container {
    width: calc(100% - 24px);
  }

  .hero-title {
    font-size: 2rem;
  }

  .btn {
    padding: 0 20px;
    font-size: 0.95rem;
  }
}