/* ==========================================================================
   艾可云 (AikeCloud) 官方推广落地页 - 原生极简秒开样式表
   无外部字体依赖、无重型框架、纯原生 CSS、支持极致轻量与秒开性能
   ========================================================================== */

:root {
  --bg-primary: #0a0d14;
  --bg-secondary: #111726;
  --bg-card: rgba(22, 30, 49, 0.75);
  --bg-card-hover: rgba(30, 41, 67, 0.9);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(59, 130, 246, 0.5);
  
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-dim: #6b7280;
  
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --accent: #06b6d4;
  --accent-purple: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #06b6d4 50%, #8b5cf6 100%);
  --tag-bg: rgba(59, 130, 246, 0.12);
  --tag-border: rgba(59, 130, 246, 0.3);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.35);
  
  --container-width: 1180px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  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-main);
  line-height: 1.6;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 10%, rgba(59, 130, 246, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.10) 0%, transparent 45%),
    radial-gradient(circle at 50% 80%, rgba(6, 182, 212, 0.08) 0%, transparent 50%);
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

img, svg {
  vertical-align: middle;
}

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

.section {
  padding: 85px 0;
  position: relative;
}

/* 标题通用组件 */
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px auto;
}

.section-tag {
  display: inline-block;
  padding: 5px 14px;
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  color: #60a5fa;
  font-size: 0.82rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.25;
  color: #ffffff;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* 按钮规范系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  font-size: 0.98rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #2563eb, #3b82f6);
  color: #ffffff;
  box-shadow: 0 4px 18px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.55);
}

.btn-glow {
  position: relative;
  overflow: hidden;
}

.btn-glow::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
}

.btn-glow:hover::after {
  opacity: 1;
}

.btn-outline {
  background: rgba(255, 255, 255, 0.05);
  color: #e5e7eb;
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
}

.btn-block {
  width: 100%;
}

/* ==========================================================================
   导航条 (Header / Navbar)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 13, 20, 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.01em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, #3b82f6, #06b6d4);
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

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

.nav-links a {
  color: var(--text-muted);
  font-size: 0.94rem;
  font-weight: 500;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* ==========================================================================
   Hero 主视觉区及顶部 AI 双聚光灯光效
   ========================================================================== */
.hero-section {
  padding: 85px 0 65px 0;
  text-align: center;
  position: relative;
  overflow: hidden; /* 防止聚光灯光晕模糊溢出页面产生水平滚动条 */
}

.hero-section > .container {
  position: relative;
  z-index: 2; /* 确保标题与内容层级位于聚光灯光效之上 */
}

/* 聚光灯容器 */
.spotlight-wrapper {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: 1;
}

/* 左侧聚光灯高光核心与斜射投射光束 */
.spotlight-left {
  position: absolute;
  top: -140px;
  left: -80px;
  width: 660px;
  height: 660px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, rgba(59, 130, 246, 0.7) 0%, rgba(6, 182, 212, 0.35) 42%, transparent 70%);
  filter: blur(85px);
  animation: spotlightPulse 7s ease-in-out infinite alternate;
  will-change: transform, opacity;
}

.beam-left {
  position: absolute;
  top: -120px;
  left: -50px;
  width: 750px;
  height: 980px;
  background: conic-gradient(
    from 115deg at 0% 0%,
    transparent 0deg,
    rgba(59, 130, 246, 0.4) 15deg,
    rgba(6, 182, 212, 0.5) 30deg,
    rgba(59, 130, 246, 0.18) 48deg,
    transparent 62deg
  );
  filter: blur(52px);
  transform: rotate(18deg);
  transform-origin: 0% 0%;
  opacity: 0.88;
  animation: beamSwayLeft 9s ease-in-out infinite alternate;
  will-change: transform, opacity;
}

/* 右侧聚光灯高光核心与斜射投射光束 */
.spotlight-right {
  position: absolute;
  top: -140px;
  right: -80px;
  width: 660px;
  height: 660px;
  border-radius: 50%;
  background: radial-gradient(circle at 65% 35%, rgba(139, 92, 246, 0.7) 0%, rgba(59, 130, 246, 0.35) 42%, transparent 70%);
  filter: blur(85px);
  animation: spotlightPulse 7s ease-in-out infinite alternate;
  animation-delay: -3.5s;
  will-change: transform, opacity;
}

.beam-right {
  position: absolute;
  top: -120px;
  right: -50px;
  width: 750px;
  height: 980px;
  background: conic-gradient(
    from 245deg at 100% 0%,
    transparent 0deg,
    rgba(139, 92, 246, 0.4) 15deg,
    rgba(59, 130, 246, 0.5) 30deg,
    rgba(147, 51, 234, 0.18) 48deg,
    transparent 62deg
  );
  filter: blur(52px);
  transform: rotate(-18deg);
  transform-origin: 100% 0%;
  opacity: 0.88;
  animation: beamSwayRight 9s ease-in-out infinite alternate;
  animation-delay: -4.5s;
  will-change: transform, opacity;
}

/* 左右双光束中心交汇区舞台泛光 */
.spotlight-center-glow {
  position: absolute;
  top: 15%;
  left: 50%;
  transform: translateX(-50%);
  width: 780px;
  height: 380px;
  background: radial-gradient(ellipse at center, rgba(59, 130, 246, 0.25) 0%, rgba(139, 92, 246, 0.18) 38%, transparent 72%);
  filter: blur(65px);
  animation: spotlightPulse 8s ease-in-out infinite alternate;
}

/* 聚光灯流光呼吸与微动动画 */
@keyframes spotlightPulse {
  0% {
    opacity: 0.65;
    transform: scale(0.96);
  }
  100% {
    opacity: 0.95;
    transform: scale(1.05);
  }
}

@keyframes beamSwayLeft {
  0% {
    transform: rotate(15deg) scaleY(0.95);
    opacity: 0.75;
  }
  100% {
    transform: rotate(22deg) scaleY(1.04);
    opacity: 0.95;
  }
}

@keyframes beamSwayRight {
  0% {
    transform: rotate(-15deg) scaleY(0.95);
    opacity: 0.75;
  }
  100% {
    transform: rotate(-22deg) scaleY(1.04);
    opacity: 0.95;
  }
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: var(--radius-full);
  color: #93c5fd;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 24px;
}

.hero-pill-badge {
  background: #3b82f6;
  color: #fff;
  font-size: 0.72rem;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  font-weight: 700;
}

.hero-title {
  font-size: 3.3rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin-bottom: 22px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: 1.22rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 36px auto;
  line-height: 1.7;
}

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

.hero-trust-badges {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  color: var(--text-dim);
  font-size: 0.88rem;
  margin-top: 24px;
  flex-wrap: wrap;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
}

.trust-item svg {
  color: #10b981;
}

/* 关键指标展示条 */
.hero-stats-banner {
  margin-top: 55px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  text-align: center;
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(10px);
}

.stat-item h3, .stat-item .stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 4px;
  display: block;
}

.stat-item p {
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* ==========================================================================
   核心优势 (Core Advantages)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 26px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: transparent;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  background: var(--bg-card-hover);
  border-color: rgba(59, 130, 246, 0.4);
  box-shadow: var(--shadow-md);
}

.feature-card:hover::before {
  background: var(--accent-gradient);
}

.feature-icon-wrapper {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #60a5fa;
  margin-bottom: 20px;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.feature-desc {
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.6;
}

/* ==========================================================================
   流媒体 & AI 大模型支持区
   ========================================================================== */
.streaming-ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.media-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  transition: var(--transition);
}

.media-box:hover {
  border-color: rgba(59, 130, 246, 0.35);
  box-shadow: var(--shadow-md);
}

.media-box-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.media-box-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.media-box.ai .media-box-icon {
  background: rgba(139, 92, 246, 0.15);
  color: #a78bfa;
  border: 1px solid rgba(139, 92, 246, 0.3);
}

.media-box.stream .media-box-icon {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.media-box-header h3 {
  font-size: 1.4rem;
  font-weight: 700;
  color: #ffffff;
}

.media-box-header p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.service-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 24px 0;
}

.service-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.07);
  font-size: 0.88rem;
  font-weight: 500;
  color: #e5e7eb;
}

.pill-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
}

.media-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 11px;
}

.media-features-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.media-features-list li svg {
  flex-shrink: 0;
  margin-top: 3px;
  color: #3b82f6;
}

/* ==========================================================================
   套餐价格对比表 (Pricing Comparison Table)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  align-items: stretch;
}

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

.pricing-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: rgba(255, 255, 255, 0.2);
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(30, 48, 86, 0.85) 0%, rgba(18, 26, 45, 0.9) 100%);
  border: 2px solid #3b82f6;
  box-shadow: 0 10px 35px -5px rgba(59, 130, 246, 0.35);
  transform: scale(1.03);
}

.pricing-card.featured:hover {
  transform: scale(1.03) translateY(-5px);
}

.pricing-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, #2563eb, #06b6d4);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.4);
}

.pricing-header {
  margin-bottom: 24px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.plan-price-wrapper {
  margin: 20px 0 24px 0;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.plan-currency {
  font-size: 1.4rem;
  font-weight: 600;
  color: #ffffff;
  vertical-align: top;
}

.plan-price {
  font-size: 3rem;
  font-weight: 900;
  color: #ffffff;
  letter-spacing: -0.03em;
  line-height: 1;
}

.plan-period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 13px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: #e5e7eb;
}

.plan-features-list li svg {
  flex-shrink: 0;
  color: #10b981;
}

.plan-features-list li.disabled {
  color: var(--text-dim);
  text-decoration: line-through;
}

.plan-features-list li.disabled svg {
  color: var(--text-dim);
}

/* ==========================================================================
   用户评价 (User Reviews / Testimonials)
   ========================================================================== */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 30px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 255, 255, 0.18);
  box-shadow: var(--shadow-md);
}

.stars {
  color: #fbbf24;
  margin-bottom: 16px;
  display: flex;
  gap: 3px;
}

.testimonial-text {
  font-size: 0.95rem;
  line-height: 1.65;
  color: #d1d5db;
  margin-bottom: 22px;
}

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

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3b82f6, #8b5cf6);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #ffffff;
  font-size: 1rem;
}

.user-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #ffffff;
}

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

/* ==========================================================================
   常见问题解答 (FAQ) - 原生 details/summary 实现
   ========================================================================== */
.faq-container {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.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: rgba(59, 130, 246, 0.35);
}

.faq-question {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  user-select: none;
}

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

.faq-chevron {
  transition: transform 0.25s ease;
  color: var(--text-muted);
}

.faq-item[open] .faq-chevron {
  transform: rotate(180deg);
  color: #3b82f6;
}

.faq-answer {
  padding: 0 24px 22px 24px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ==========================================================================
   页脚 (Footer) - 严格遵循只保留四个标题并开新页面
   ========================================================================== */
.site-footer {
  background: #07090f;
  border-top: 1px solid var(--border-color);
  padding: 55px 0 45px 0;
  text-align: center;
}

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

.footer-link {
  font-size: 1.05rem;
  font-weight: 600;
  color: #d1d5db;
  padding: 8px 12px;
  position: relative;
  transition: var(--transition);
}

.footer-link:hover {
  color: #3b82f6;
}

.footer-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: #3b82f6;
  transition: var(--transition);
  transform: translateX(-50%);
}

.footer-link:hover::after {
  width: 80%;
}

.footer-copy {
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* ==========================================================================
   二级说明页公共样式 (关于我们 / 服务条款 / 隐私政策 / 网站地图)
   ========================================================================== */
.doc-header {
  padding: 40px 0 20px 0;
  border-bottom: 1px solid var(--border-color);
}

.doc-content-wrapper {
  max-width: 850px;
  margin: 40px auto 80px auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
}

.doc-article h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: #ffffff;
  margin: 36px 0 16px 0;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.doc-article h2:first-of-type {
  margin-top: 0;
}

.doc-article h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: #93c5fd;
  margin: 22px 0 10px 0;
}

.doc-article p {
  color: #d1d5db;
  font-size: 0.98rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.doc-article ul, .doc-article ol {
  margin-left: 24px;
  margin-bottom: 20px;
  color: #d1d5db;
}

.doc-article li {
  margin-bottom: 8px;
  line-height: 1.7;
}

.back-home-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 30px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #60a5fa;
  font-weight: 600;
  font-size: 0.95rem;
}

.back-link:hover {
  color: #93c5fd;
  text-decoration: underline;
}

/* 网站地图节点树 */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 24px;
}

.sitemap-card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sitemap-card h3 {
  font-size: 1.15rem;
  color: #ffffff;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sitemap-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sitemap-list a {
  color: #9ca3af;
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  gap: 6px;
}

.sitemap-list a:hover {
  color: #3b82f6;
  padding-left: 4px;
}

/* ==========================================================================
   响应式媒体查询 (@media) - 确保手机端单栏完美呈现，触控友好
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.6rem;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-card.featured {
    transform: none;
  }
  .pricing-card.featured:hover {
    transform: translateY(-5px);
  }
}

@media (max-width: 768px) {
  /* 移动端聚光灯自适应尺寸 */
  .spotlight-left, .spotlight-right {
    width: 380px;
    height: 380px;
    filter: blur(60px);
  }
  .beam-left, .beam-right {
    width: 420px;
    height: 600px;
    filter: blur(40px);
  }
  .spotlight-center-glow {
    width: 340px;
    height: 200px;
  }

  .section {
    padding: 60px 0;
  }

  .nav-links {
    display: none; /* 移动端隐藏冗长文字菜单，保留品牌和行动按钮保证极速操作 */
  }

  .hero-title {
    font-size: 2.1rem;
    line-height: 1.25;
  }

  .hero-subtitle {
    font-size: 1.02rem;
  }

  .hero-cta-group {
    flex-direction: column;
    width: 100%;
    max-width: 380px;
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta-group .btn {
    width: 100%;
    min-height: 52px; /* 适合手指点击的大尺寸触控设计 */
    font-size: 1.05rem;
  }

  .hero-stats-banner {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 20px 16px;
  }

  .stat-item h3, .stat-item .stat-value {
    font-size: 1.6rem;
  }

  .features-grid {
    grid-template-columns: 1fr; /* 手机端单栏完美展示 */
    gap: 16px;
  }

  .streaming-ai-grid {
    grid-template-columns: 1fr; /* 单栏展示 */
    gap: 20px;
  }

  .pricing-grid {
    grid-template-columns: 1fr; /* 手机端单栏垂直对比 */
    gap: 24px;
  }

  .pricing-card {
    padding: 30px 20px;
  }

  .pricing-card .btn {
    min-height: 50px; /* 大触控目标 */
  }

  .testimonials-grid {
    grid-template-columns: 1fr; /* 单栏呈现好评 */
    gap: 18px;
  }

  .footer-nav {
    flex-direction: column;
    gap: 18px;
  }

  .footer-link {
    font-size: 1.08rem;
    padding: 8px 24px;
    width: 100%;
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-sm);
  }

  .doc-content-wrapper {
    padding: 24px 18px;
    margin: 20px auto 40px auto;
  }

  .sitemap-grid {
    grid-template-columns: 1fr;
  }

  .tech-grid-cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1024px) {
  .tech-grid-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.85rem;
  }

  .hero-stats-banner {
    grid-template-columns: 1fr;
  }

  .section-title {
    font-size: 1.75rem;
  }
}

/* ==========================================================================
   高科技网格卡片 (Tech Grid Cards)
   ========================================================================== */
.tech-grid-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 36px;
}

.tech-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
  backdrop-filter: blur(8px);
}

.tech-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, #3b82f6, #06b6d4, #8b5cf6);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.tech-card:hover {
  transform: translateY(-5px);
  border-color: rgba(59, 130, 246, 0.4);
  box-shadow: 0 12px 30px -5px rgba(0, 0, 0, 0.5), 0 0 15px rgba(59, 130, 246, 0.15);
  background: var(--bg-card-hover);
}

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

.tech-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.tech-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.tech-badge.hot {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border-color: rgba(239, 68, 68, 0.3);
}

.tech-meta {
  font-size: 0.8rem;
  color: var(--text-dim);
}

.tech-card-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.45;
  margin-bottom: 12px;
  transition: color 0.2s;
}

.tech-card:hover .tech-card-title {
  color: #93c5fd;
}

.tech-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.tech-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.tech-read-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: #38bdf8;
  transition: transform 0.2s;
}

.tech-read-btn:hover {
  color: #7dd3fc;
  transform: translateX(3px);
}