/* ==========================================================================
   宝妈云 (BaomaCloud.sbs) 官方 landing - 高对比度【黑·黑·白】视觉设计系统
   ========================================================================== */

:root {
  --primary: #007aff;
  --primary-dark: #0056b3;
  --accent: #00f0ff;
  --accent-glow: rgba(0, 240, 255, 0.25);
  
  /* 三重背景调色盘：纯黑 (Pitch Black)、深黑 (Obsidian Black)、亮白 (Pure White) */
  --bg-pitch-black: #000000;
  --bg-deep-black: #08080c;
  --bg-card-black: #101018;
  --bg-card-hover: #181824;
  --bg-pure-white: #ffffff;
  --bg-light-gray: #f8fafc;
  
  --text-white: #ffffff;
  --text-muted: #a0aec0;
  --text-dark: #0a0a0f;
  --text-dark-muted: #4a5568;
  
  --border-dark: rgba(255, 255, 255, 0.12);
  --border-light: rgba(0, 0, 0, 0.08);
  --border-highlight: rgba(0, 240, 255, 0.4);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-full: 9999px;

  --shadow-dark: 0 10px 30px rgba(0, 0, 0, 0.8);
  --shadow-white: 0 10px 30px rgba(0, 0, 0, 0.08);

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-pitch-black);
  color: var(--text-white);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.2s ease;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Section Title & Subtitle */
.section-title {
  text-align: center;
  font-size: 2.35rem;
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.section-title.light-text {
  color: #ffffff;
}

.section-title.dark-text {
  color: var(--text-dark);
}

.section-subtitle {
  text-align: center;
  font-size: 1.05rem;
  max-width: 720px;
  margin: 0 auto 48px auto;
}

.section-subtitle.light-muted {
  color: var(--text-muted);
}

.section-subtitle.dark-muted {
  color: var(--text-dark-muted);
}

/* Header (纯黑极简背景) */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-dark);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.35rem;
  color: #ffffff;
}

.logo-brand img {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  box-shadow: 0 0 14px rgba(255, 255, 255, 0.2);
}

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

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: #ffffff;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-recommend {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  border-radius: var(--radius-full);
  background: #ffffff;
  color: #000000;
  font-size: 0.9rem;
  font-weight: 700;
  border: 1px solid #ffffff;
  transition: all 0.2s ease;
}

.btn-recommend:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #000000;
  box-shadow: 0 0 18px var(--accent-glow);
  transform: translateY(-1px);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  background: linear-gradient(135deg, #007aff 0%, #00f0ff 100%);
  color: #000000;
  font-weight: 700;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 18px rgba(0, 240, 255, 0.3);
  border: none;
  cursor: pointer;
  white-space: nowrap;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 240, 255, 0.5);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  background: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer;
  white-space: nowrap;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: #ffffff;
  transform: translateY(-2px);
}

.btn-recommend-hero {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  background: #ffffff;
  color: #000000;
  font-weight: 700;
  border-radius: var(--radius-full);
  border: 1px solid #ffffff;
  cursor: pointer;
  white-space: nowrap;
  box-shadow: 0 4px 18px rgba(255, 255, 255, 0.2);
  transition: all 0.2s ease;
}

.btn-recommend-hero:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #000000;
  box-shadow: 0 8px 24px var(--accent-glow);
  transform: translateY(-2px);
}

/* Hero Section (黑色第一层) */
.hero {
  padding: 90px 0 70px 0;
  text-align: center;
  background: radial-gradient(circle at 50% 10%, rgba(255, 255, 255, 0.08) 0%, var(--bg-pitch-black) 70%);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-full);
  color: #ffffff;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 28px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 22px;
  color: #ffffff;
}

.hero-title span {
  background: linear-gradient(135deg, #ffffff 0%, #00f0ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 800px;
  margin: 0 auto 38px auto;
}

.hero-ctas {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 52px;
  flex-wrap: wrap;
}

.hero-features-strip {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  padding: 22px 30px;
  background: var(--bg-card-black);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  max-width: 940px;
  margin: 0 auto;
  box-shadow: var(--shadow-dark);
}

.strip-item {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 600;
}

.strip-item svg {
  width: 20px;
  height: 20px;
  color: var(--accent);
}

/* 我们的优势 Features Section (深黑第二层) */
.features-section {
  padding: 90px 0;
  background: var(--bg-deep-black);
  border-top: 1px solid var(--border-dark);
  border-bottom: 1px solid var(--border-dark);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 26px;
}

.feature-card {
  background: var(--bg-card-black);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  padding: 34px 26px;
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-highlight);
  background: var(--bg-card-hover);
  box-shadow: 0 12px 30px rgba(0, 240, 255, 0.15);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: #ffffff;
  color: #000000;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
  box-shadow: 0 0 15px rgba(255, 255, 255, 0.2);
}

.feature-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Pricing Section (高对比度纯白卡片 & 纯黑融合) */
.pricing-section {
  padding: 90px 0;
  background: var(--bg-pitch-black);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 26px;
}

.pricing-card {
  background: var(--bg-card-black);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

/* 高对比度亮点：VIP高级套餐采用【纯白背景 + 黑色文字】 */
.pricing-card.popular {
  background: var(--bg-pure-white);
  color: var(--text-dark);
  border-color: #ffffff;
  box-shadow: 0 15px 45px rgba(255, 255, 255, 0.25);
  transform: scale(1.03);
}

.pricing-card.popular .pricing-header h3 {
  color: var(--text-dark);
}

.pricing-card.popular .pricing-desc {
  color: var(--text-dark-muted);
}

.pricing-card.popular .pricing-price {
  color: var(--text-dark);
}

.pricing-card.popular .pricing-price .unit {
  color: var(--text-dark-muted);
}

.pricing-card.popular .pricing-features li {
  color: var(--text-dark);
}

.pricing-card.popular .pricing-features svg {
  color: #007aff;
}

.popular-tag {
  position: absolute;
  top: -14px;
  right: 24px;
  background: #000000;
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 800;
  padding: 5px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  border: 1px solid #ffffff;
}

.pricing-header h3 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: #ffffff;
}

.pricing-desc {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 22px;
  min-height: 40px;
}

.pricing-price {
  font-size: 2.6rem;
  font-weight: 900;
  color: #ffffff;
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-price .unit {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  color: #e2e8f0;
  font-size: 0.93rem;
}

.pricing-features svg {
  width: 18px;
  height: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

/* Articles Section (深黑第三层) */
.articles-section {
  padding: 90px 0;
  background: var(--bg-deep-black);
  border-top: 1px solid var(--border-dark);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}

.article-card {
  background: var(--bg-card-black);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  padding: 30px;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: #ffffff;
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.08);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
  font-size: 0.825rem;
}

.article-tag {
  background: #ffffff;
  color: #000000;
  padding: 3px 12px;
  border-radius: var(--radius-full);
  font-weight: 700;
}

.article-date {
  color: var(--text-muted);
}

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

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

.article-excerpt {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 22px;
  flex-grow: 1;
}

.article-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #ffffff;
  font-size: 0.9rem;
  font-weight: 700;
}

.article-link:hover {
  color: var(--accent);
  gap: 10px;
}

/* Reviews / Testimonials Section (纯白背景区域，满足“黑色黑色白色”的白色对比层) */
.reviews-section {
  padding: 90px 0;
  background: var(--bg-pure-white);
  color: var(--text-dark);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 26px;
}

.review-card {
  background: var(--bg-light-gray);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 30px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-white);
}

.review-stars {
  color: #f59e0b;
  font-size: 1.15rem;
  margin-bottom: 16px;
}

.review-text {
  color: #334155;
  font-size: 0.96rem;
  line-height: 1.65;
  margin-bottom: 22px;
  font-style: italic;
  flex-grow: 1;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 14px;
}

.avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: #000000;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #ffffff;
  font-size: 1.1rem;
}

.author-info h4 {
  font-size: 0.98rem;
  font-weight: 800;
  color: var(--text-dark);
  display: flex;
  align-items: center;
  gap: 6px;
}

.verified-badge {
  color: #007aff;
  font-size: 0.8rem;
  font-weight: 700;
}

.author-info p {
  color: var(--text-dark-muted);
  font-size: 0.825rem;
}

/* FAQ Section (纯黑回归层) */
.faq-section {
  padding: 90px 0;
  background: var(--bg-pitch-black);
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.faq-item {
  background: var(--bg-card-black);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.2s ease;
}

.faq-item summary {
  padding: 22px 26px;
  font-size: 1.08rem;
  font-weight: 700;
  color: #ffffff;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--accent);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-content {
  padding: 0 26px 22px 26px;
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 4px;
  padding-top: 18px;
}

/* Single Article Page Layout */
.article-container {
  max-width: 900px;
  margin: 40px auto 80px auto;
  padding: 0 20px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 28px;
}

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

.article-header {
  margin-bottom: 40px;
  border-bottom: 1px solid var(--border-dark);
  padding-bottom: 30px;
}

.article-header h1 {
  font-size: 2.35rem;
  font-weight: 800;
  line-height: 1.3;
  color: #ffffff;
  margin-bottom: 16px;
}

.article-header-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #cbd5e1;
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 700;
  color: #ffffff;
  margin: 40px 0 16px 0;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-dark);
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 600;
  color: #f1f5f9;
  margin: 28px 0 12px 0;
}

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

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

.article-body li {
  margin-bottom: 8px;
}

.article-body blockquote {
  border-left: 4px solid #ffffff;
  background: rgba(255, 255, 255, 0.05);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: #e2e8f0;
  font-style: italic;
}

.article-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 4px;
}

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

.article-cta-box {
  background: var(--bg-card-black);
  border: 1px solid #ffffff;
  border-radius: var(--radius-lg);
  padding: 36px;
  text-align: center;
  margin: 48px 0;
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.1);
}

.article-cta-box h3 {
  font-size: 1.6rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 12px;
}

.article-cta-box p {
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Footer & PBN Links (核心任务 2：页脚 PBN 权重管道) */
.footer {
  background: #000000;
  border-top: 1px solid var(--border-dark);
  padding: 60px 0 30px 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-top {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 40px;
  margin-bottom: 48px;
}

.footer-col h4 {
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  text-align: center;
}

/* PBN Low-Profile Friend Links Requirement */
.pbn-links-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  font-size: 0.85rem;
  color: #718096;
  margin-bottom: 8px;
}

.pbn-links-area span {
  color: #4a5568;
  font-weight: 500;
}

.pbn-links-area a {
  color: #a0aec0;
  text-decoration: none;
  transition: color 0.2s ease;
}

.pbn-links-area a:hover {
  color: #ffffff;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.35rem;
  }
  
  .nav-links {
    display: none;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  
  .article-header h1 {
    font-size: 1.85rem;
  }
  
  .section-title {
    font-size: 1.75rem;
  }
}