/* ==========================================================================
   贝贝云 (beibeicloud.site) - 纯原生极简高速 CSS 样式规范
   无外部框架 | 无外部字体阻塞 | 响应式自适应 | 深色科技美学
   ========================================================================== */

:root {
  --bg-primary: #0a0d14;
  --bg-secondary: #111726;
  --bg-card: #161f33;
  --bg-card-hover: #1c2742;
  --border-color: #24314f;
  --border-focus: #3b82f6;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-color: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  --badge-bg: rgba(59, 130, 246, 0.15);
  --badge-text: #60a5fa;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --container-max: 1200px;
  --header-height: 72px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --transition: all 0.25s ease-in-out;
}

/* 全局重置与无障碍基线 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

/* 键盘可访问无障碍跳转链接 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--accent-color);
  color: #ffffff;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  font-weight: 600;
  text-decoration: none;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 20px;
  outline: 3px solid #93c5fd;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* 锚点防遮挡 */
section[id], h2[id], h3[id] {
  scroll-margin-top: calc(var(--header-height) + 24px);
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  height: var(--header-height);
  background-color: rgba(10, 13, 20, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  display: flex;
  align-items: center;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.brand-icon img,
.brand-icon svg {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

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

.main-nav a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
  padding: 8px 4px;
}

.main-nav a:hover,
.main-nav a.active {
  color: #60a5fa;
}

.nav-cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  background: var(--accent-gradient);
  color: #ffffff !important;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: var(--transition);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-cta-btn:hover {
  filter: brightness(1.15);
  transform: translateY(-1px);
}

/* 按钮通用规范 (保障 44x44px 触控标准，强制单行不对折) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 0 22px;
  border-radius: var(--radius-sm);
  font-size: 0.98rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  line-height: 1;
  white-space: nowrap;
  word-break: keep-all;
  flex-shrink: 0;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: #3b82f6;
  transform: translateY(-2px);
}

/* 主视觉区 (Hero Section) */
.hero-section {
  padding: 88px 0 68px;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: radial-gradient(ellipse at top, rgba(37, 99, 235, 0.22) 0%, rgba(17, 24, 39, 0.4) 50%, rgba(10, 13, 20, 1) 100%);
}

.hero-section .container {
  position: relative;
  z-index: 2;
}

/* 贝壳流星群容器 - 首页与内页通用 */
.shell-meteors-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: 1;
}

/* 内页流星背景天际线 */
.page-meteors-bg {
  position: absolute;
  top: var(--header-height);
  left: 0;
  width: 100%;
  height: 600px;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.page-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 20px 80px;
  position: relative;
  z-index: 2;
}

/* 经典高速流星实体 (从左上方朝右下方俯冲) */
.shell-meteor {
  position: absolute;
  display: inline-flex;
  align-items: center;
  transform: rotate(38deg);
  opacity: 0;
  pointer-events: none;
  will-change: transform, opacity;
  animation: classicMeteorFall 3.6s cubic-bezier(0.22, 0.61, 0.36, 1) infinite;
}

/* 经典流星修长渐变拖尾 (尾端指向左上方) */
.shell-meteor-tail {
  width: 180px;
  height: 2px;
  background: linear-gradient(
    to right,
    transparent 0%,
    rgba(56, 189, 248, 0.15) 20%,
    rgba(96, 165, 250, 0.6) 70%,
    #ffffff 100%
  );
  border-radius: 999px;
  box-shadow: 0 0 8px rgba(56, 189, 248, 0.8), 0 0 16px rgba(96, 165, 250, 0.5);
  margin-right: -2px;
}

/* 经典流星发光星核头部 (迎风俯冲朝向右下，璀璨聚光核) */
.shell-meteor-head {
  width: 6px;
  height: 6px;
  background-color: #ffffff;
  border-radius: 50%;
  box-shadow:
    0 0 6px 2px #ffffff,
    0 0 14px 4px #60a5fa,
    0 0 24px 6px rgba(56, 189, 248, 0.85);
  flex-shrink: 0;
  display: block;
}

/* 经典流星自全域顶端与左侧落下向右下方的宏大轨迹 */
@keyframes classicMeteorFall {
  0% {
    opacity: 0;
    transform: translate3d(-40px, -40px, 0) rotate(38deg) scale(0.7);
  }
  15% {
    opacity: 1;
  }
  75% {
    opacity: 0.95;
  }
  100% {
    opacity: 0;
    transform: translate3d(780px, 620px, 0) rotate(38deg) scale(1.05);
  }
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background-color: var(--badge-bg);
  color: var(--badge-text);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
  border: 1px solid rgba(96, 165, 250, 0.3);
}

.hero-title {
  margin-bottom: 24px;
  line-height: 1.25;
}

/* “贝贝云官网” 字体最大 + 滑动流光动画特效 */
.hero-title-top {
  display: block;
  font-size: clamp(3rem, 7vw, 5.2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  /* 动态水平滑动画质渐变 */
  background: linear-gradient(
    105deg,
    #60a5fa 0%,
    #93c5fd 20%,
    #ffffff 40%,
    #38bdf8 60%,
    #818cf8 80%,
    #60a5fa 100%
  );
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 35px rgba(59, 130, 246, 0.35);
  animation:
    heroTitleSlideIn 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards,
    heroTitleShimmer 4.5s linear infinite;
}

/* 瞬时抵达全球的下一代企业级专线矩阵 - 次级大标题 */
.hero-title-bottom {
  display: block;
  font-size: clamp(1.25rem, 2.8vw, 2.1rem);
  font-weight: 700;
  color: #f1f5f9;
  letter-spacing: -0.01em;
  animation: heroSubSlideIn 0.9s 0.15s cubic-bezier(0.16, 1, 0.3, 1) both;
}

/* 滑动特效关键帧 */
@keyframes heroTitleSlideIn {
  0% {
    opacity: 0;
    transform: translateY(28px) scale(0.96);
  }
  100% {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes heroSubSlideIn {
  0% {
    opacity: 0;
    transform: translateY(20px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes heroTitleShimmer {
  0% {
    background-position: 0% center;
  }
  100% {
    background-position: 200% center;
  }
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 820px;
  margin: 0 auto 24px;
  line-height: 1.6;
}

.hero-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  max-width: 740px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-highlights {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.highlight-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.highlight-item svg {
  color: var(--success-color);
}

/* 区块通用结构 */
.section {
  padding: 72px 0;
}

.section-alt {
  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 48px;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.3rem);
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

/* 核心优势卡片网格 (3图文卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: #3b82f6;
  background-color: var(--bg-card-hover);
}

.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-sm);
  background: rgba(37, 99, 235, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: #60a5fa;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: #ffffff;
}

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

/* 流媒体与 AI 支持图卡 */
.support-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.support-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 16px;
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
}

.support-tag.ai-tag {
  background: rgba(139, 92, 246, 0.15);
  color: #a78bfa;
}

.support-card h3 {
  font-size: 1.4rem;
  margin-bottom: 12px;
  color: #ffffff;
}

.support-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 24px;
}

.platform-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.platform-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 0.85rem;
  color: var(--text-primary);
}

/* 套餐价格对比表 */
.pricing-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 640px;
}

.pricing-table caption {
  padding: 16px;
  text-align: left;
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border-color);
}

.pricing-table th,
.pricing-table td {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
}

.pricing-table td:last-child {
  white-space: nowrap;
  width: 1%;
}

.pricing-table .btn {
  min-width: 104px;
  padding: 0 18px;
  white-space: nowrap;
  word-break: keep-all;
}

.pricing-table th {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.05rem;
}

.pricing-table tr:last-child td {
  border-bottom: none;
}

.pricing-table tr:hover td {
  background-color: rgba(255, 255, 255, 0.02);
}

.price-val {
  font-size: 1.4rem;
  font-weight: 800;
  color: #60a5fa;
}

.price-val span {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-secondary);
}

/* 用户真实评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  color: #fbbf24;
  margin-bottom: 12px;
  letter-spacing: 2px;
}

.review-text {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar-initial {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
}

.user-info h4 {
  font-size: 0.95rem;
  color: var(--text-primary);
}

.user-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* FAQ 常见问题 (默认展开 details/summary) */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 860px;
  margin: 0 auto;
}

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

.faq-item:hover {
  border-color: #3b82f6;
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1.1rem;
  font-weight: 600;
  color: #ffffff;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-item summary::after {
  content: "▾";
  font-size: 1.2rem;
  color: #60a5fa;
  transition: transform 0.2s ease;
}

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

.faq-content {
  padding: 0 24px 20px 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 4px;
  padding-top: 16px;
}

/* 页脚规范 (仅保留四个标题链接，新页面打开) */
.site-footer {
  background-color: #07090f;
  border-top: 1px solid var(--border-color);
  padding: 48px 0 32px;
  margin-top: auto;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-nav {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
  padding: 8px 4px;
}

.footer-nav a:hover {
  color: #60a5fa;
  text-decoration: underline;
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.85rem;
  text-align: center;
}

/* 内页/文章通用排版样式 */
.page-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 20px 80px;
}

.breadcrumbs {
  display: flex;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.breadcrumbs a {
  color: var(--text-secondary);
  text-decoration: none;
}

.breadcrumbs a:hover {
  color: #60a5fa;
}

.article-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
}

.article-header h1 {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  line-height: 1.3;
  margin-bottom: 16px;
  color: #ffffff;
}

.article-meta {
  display: flex;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.prose {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.05rem;
}

.prose h2 {
  color: #ffffff;
  font-size: 1.5rem;
  margin: 36px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.prose h3 {
  color: #ffffff;
  font-size: 1.25rem;
  margin: 24px 0 12px;
}

.prose p {
  margin-bottom: 20px;
}

.prose ul, .prose ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.prose li {
  margin-bottom: 8px;
}

.prose a {
  color: #60a5fa;
  text-decoration: underline;
}

.prose a:hover {
  color: #93c5fd;
}

.article-faq {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
}

/* 知识库列表卡片 */
.articles-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.article-summary-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: var(--transition);
}

.article-summary-card:hover {
  border-color: #3b82f6;
  transform: translateY(-2px);
}

.article-summary-card h2 {
  font-size: 1.35rem;
  margin-bottom: 12px;
}

.article-summary-card h2 a {
  color: #ffffff;
  text-decoration: none;
}

.article-summary-card h2 a:hover {
  color: #60a5fa;
}

.article-summary-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

.article-footer-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* 响应式媒体查询 (@media) */
@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }
  
  .features-grid,
  .support-grid,
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  
  .main-nav ul {
    gap: 14px;
  }
  
  .hero-section {
    padding: 48px 0 40px;
  }
  
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-cta-group .btn {
    width: 100%;
  }
  
  .footer-nav {
    flex-direction: column;
    align-items: center;
    gap: 16px;
  }
  
  .pricing-table th, 
  .pricing-table td {
    padding: 14px 16px;
  }
}

@media (max-width: 480px) {
  .brand-logo span {
    font-size: 1.15rem;
  }
  .main-nav ul {
    gap: 10px;
  }
  .main-nav a {
    font-size: 0.85rem;
    padding: 6px 2px;
  }
}

/* 无障碍减少动画支持 */
@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;
  }
}