/* ==========================================================================
   寰宇云 (HuanyuYun) - 官方推广落地页核心样式表
   风格：宇宙星际风 (Cosmic Interstellar Theme)
   设计特点：深邃星空墨黑、星云紫与荧光青渐变、星系微光粒子感、玻璃拟态质感卡片
   无外部框架，纯原生 CSS，高性能秒开
   ========================================================================== */

:root {
  /* 宇宙星际主题配色 */
  --bg-deep-space: #070913;
  --bg-space-dark: #0b1120;
  --bg-card: rgba(16, 24, 48, 0.72);
  --bg-card-hover: rgba(26, 38, 74, 0.85);
  --border-glow: rgba(99, 102, 241, 0.28);
  --border-glow-hover: rgba(56, 189, 248, 0.55);
  
  /* 星云高光与渐变 */
  --cosmic-purple: #818cf8;
  --cosmic-blue: #38bdf8;
  --cosmic-cyan: #22d3ee;
  --cosmic-accent: #a855f7;
  --cosmic-gold: #fbbf24;
  
  /* 文字对比度严格符合 WCAG AAA / AA 规范 */
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-gradient: linear-gradient(135deg, #ffffff 0%, #cbd5e1 40%, #38bdf8 100%);
  --hero-gradient: linear-gradient(135deg, #ffffff 10%, #a5b4fc 50%, #38bdf8 90%);
  --btn-gradient: linear-gradient(135deg, #6366f1 0%, #3b82f6 50%, #06b6d4 100%);
  --btn-gradient-hover: linear-gradient(135deg, #4f46e5 0%, #2563eb 50%, #0891b2 100%);
  
  /* 尺寸与间距规范 */
  --max-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --nav-height: 72px;
  
  /* 阴影效果 */
  --shadow-glow: 0 0 25px rgba(99, 102, 241, 0.25);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.7);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 20px);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-deep-space);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-color: var(--bg-deep-space);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ==========================================================================
   宇宙星际动态特效层 (Cosmic Space FX)
   采用纯原生 CSS 与 GPU 硬件加速，零外部库，零阻塞秒开
   ========================================================================== */

/* 星云慢速呼吸与色彩漂移 */
body::before {
  content: "";
  position: fixed;
  inset: -50%;
  width: 200%;
  height: 200%;
  z-index: -3;
  pointer-events: none;
  background: 
    radial-gradient(circle at 25% 20%, rgba(99, 102, 241, 0.22) 0%, transparent 40%),
    radial-gradient(circle at 75% 35%, rgba(56, 189, 248, 0.18) 0%, transparent 45%),
    radial-gradient(circle at 45% 75%, rgba(168, 85, 247, 0.16) 0%, transparent 45%),
    radial-gradient(circle at 80% 85%, rgba(34, 211, 238, 0.14) 0%, transparent 40%),
    linear-gradient(180deg, #070913 0%, #090e1d 50%, #060810 100%);
  animation: cosmic-nebula-drift 28s ease-in-out infinite alternate;
}

@keyframes cosmic-nebula-drift {
  0% {
    transform: translate(0, 0) scale(1) rotate(0deg);
  }
  50% {
    transform: translate(-3%, 2%) scale(1.05) rotate(1.5deg);
  }
  100% {
    transform: translate(2%, -3%) scale(0.98) rotate(-1.5deg);
  }
}

/* 密集璀璨星空背景与异步闪烁特效 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  pointer-events: none;
  background-image: 
    radial-gradient(1.5px 1.5px at 40px 60px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(1.2px 1.2px at 120px 180px, #38bdf8, rgba(0,0,0,0)),
    radial-gradient(1.8px 1.8px at 240px 90px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(1px 1px at 350px 240px, #cbd5e1, rgba(0,0,0,0)),
    radial-gradient(2px 2px at 480px 140px, #a855f7, rgba(0,0,0,0)),
    radial-gradient(1.4px 1.4px at 620px 320px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(1px 1px at 750px 80px, #38bdf8, rgba(0,0,0,0)),
    radial-gradient(1.8px 1.8px at 890px 210px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(1.2px 1.2px at 980px 360px, #22d3ee, rgba(0,0,0,0)),
    radial-gradient(1.5px 1.5px at 1100px 150px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(2.2px 2.2px at 1300px 270px, #fbbf24, rgba(0,0,0,0)),
    radial-gradient(1px 1px at 1420px 80px, #ffffff, rgba(0,0,0,0));
  background-repeat: repeat;
  background-size: 800px 600px;
  animation: cosmic-star-twinkle 6s ease-in-out infinite alternate;
}

@keyframes cosmic-star-twinkle {
  0% {
    opacity: 0.65;
    filter: drop-shadow(0 0 2px rgba(255, 255, 255, 0.4));
  }
  50% {
    opacity: 0.95;
    filter: drop-shadow(0 0 6px rgba(56, 189, 248, 0.8));
  }
  100% {
    opacity: 0.75;
    filter: drop-shadow(0 0 3px rgba(168, 85, 247, 0.6));
  }
}

/* 流星 / 陨石划破星空特效容器 */
.cosmic-meteor-container {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}

.meteor {
  position: absolute;
  width: 140px;
  height: 2px;
  background: linear-gradient(90deg, #ffffff 0%, rgba(56, 189, 248, 0.8) 50%, transparent 100%);
  filter: drop-shadow(0 0 6px #38bdf8);
  border-radius: 999px;
  opacity: 0;
  transform: rotate(-35deg);
}

.meteor::before {
  content: "";
  position: absolute;
  left: 0;
  top: -2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 0 10px 2px #38bdf8, 0 0 18px 4px #818cf8;
}

/* 多颗流星按不同周期与轨迹交替划过 */
.meteor-1 {
  top: 8%;
  right: 15%;
  animation: meteor-animation-1 9s ease-in-out infinite;
  animation-delay: 1.5s;
}

.meteor-2 {
  top: 25%;
  right: 35%;
  width: 180px;
  animation: meteor-animation-2 13s ease-in-out infinite;
  animation-delay: 5s;
}

.meteor-3 {
  top: 45%;
  right: 8%;
  width: 120px;
  animation: meteor-animation-3 11s ease-in-out infinite;
  animation-delay: 8.5s;
}

@keyframes meteor-animation-1 {
  0% {
    transform: translate(120px, -120px) rotate(-35deg);
    opacity: 0;
  }
  8% {
    opacity: 1;
  }
  18% {
    transform: translate(-650px, 650px) rotate(-35deg);
    opacity: 0;
  }
  100% {
    transform: translate(-650px, 650px) rotate(-35deg);
    opacity: 0;
  }
}

@keyframes meteor-animation-2 {
  0% {
    transform: translate(150px, -150px) rotate(-38deg);
    opacity: 0;
  }
  6% {
    opacity: 1;
  }
  15% {
    transform: translate(-800px, 800px) rotate(-38deg);
    opacity: 0;
  }
  100% {
    transform: translate(-800px, 800px) rotate(-38deg);
    opacity: 0;
  }
}

@keyframes meteor-animation-3 {
  0% {
    transform: translate(100px, -100px) rotate(-32deg);
    opacity: 0;
  }
  10% {
    opacity: 0.9;
  }
  20% {
    transform: translate(-600px, 600px) rotate(-32deg);
    opacity: 0;
  }
  100% {
    transform: translate(-600px, 600px) rotate(-32deg);
    opacity: 0;
  }
}

/* 键盘无障碍跳过入口 */
.skip-link {
  position: absolute;
  top: -60px;
  left: 20px;
  background: var(--cosmic-purple);
  color: #fff;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  text-decoration: none;
  font-weight: 600;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 15px;
  outline: 2px solid #fff;
}

/* 焦点样式 */
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--cosmic-cyan);
  outline-offset: 3px;
}

/* 容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(7, 9, 19, 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  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: 12px;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 1.28rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

/* 星系 Logo SVG 效果 */
.galaxy-icon {
  width: 38px;
  height: 38px;
  display: inline-block;
  animation: galaxy-spin 24s linear infinite;
  filter: drop-shadow(0 0 8px rgba(56, 189, 248, 0.6));
}

@keyframes galaxy-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

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

.nav-menu {
  display: flex;
  align-items: center;
  gap: 26px;
  list-style: none;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.96rem;
  font-weight: 500;
  transition: color 0.2s ease;
  position: relative;
  padding: 6px 0;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--btn-gradient);
  transition: width 0.25s ease;
}
.nav-link:hover::after {
  width: 100%;
}

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

/* 标准 CTA 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  min-height: 44px;
  min-width: 44px;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--btn-gradient);
  color: #ffffff;
  box-shadow: 0 4px 18px rgba(59, 130, 246, 0.38);
}

.btn-primary:hover {
  background: var(--btn-gradient-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(59, 130, 246, 0.55);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.16);
  border-color: var(--cosmic-cyan);
  color: #ffffff;
}

.btn-lg {
  padding: 15px 34px;
  font-size: 1.1rem;
}

/* Hero 主视觉区 */
.hero-section {
  padding: 90px 0 70px;
  text-align: center;
  position: relative;
}

/* 主视觉区星核引力光晕特效 */
.hero-section::before {
  content: "";
  position: absolute;
  top: 45%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 680px;
  height: 400px;
  max-width: 90vw;
  background: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.28) 0%, rgba(56, 189, 248, 0.16) 45%, transparent 72%);
  filter: blur(40px);
  z-index: -1;
  pointer-events: none;
  animation: hero-core-pulse 7s ease-in-out infinite alternate;
}

@keyframes hero-core-pulse {
  0% {
    transform: translate(-50%, -50%) scale(0.92);
    opacity: 0.65;
  }
  100% {
    transform: translate(-50%, -50%) scale(1.12);
    opacity: 0.95;
  }
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.35);
  color: var(--cosmic-cyan);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 24px;
  box-shadow: 0 0 16px rgba(99, 102, 241, 0.2);
}

.hero-title {
  font-size: 2.85rem;
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 22px;
  background: var(--hero-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--cosmic-cyan);
  font-weight: 600;
  margin-bottom: 16px;
}

.hero-desc {
  max-width: 780px;
  margin: 0 auto 34px;
  font-size: 1.08rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 900px;
  margin: 45px auto 0;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-card);
}

.stat-item {
  text-align: center;
}

.stat-num {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--cosmic-cyan);
  display: block;
}

.stat-label {
  font-size: 0.86rem;
  color: var(--text-muted);
}

/* 通用区块排版 */
.section-padding {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 54px;
}

.section-tag {
  color: var(--cosmic-purple);
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 10px;
  display: block;
}

.section-title {
  font-size: 2.15rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: #ffffff;
}

.section-desc {
  font-size: 1.02rem;
  color: var(--text-secondary);
}

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

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow-hover);
  box-shadow: 0 14px 34px -10px rgba(56, 189, 248, 0.3);
}

.feature-icon-wrapper {
  width: 62px;
  height: 62px;
  border-radius: var(--radius-md);
  background: rgba(99, 102, 241, 0.18);
  border: 1px solid rgba(99, 102, 241, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
  color: var(--cosmic-cyan);
}

.feature-icon-wrapper svg {
  width: 32px;
  height: 32px;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: #fff;
}

.feature-text {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* 流媒体与 AI 支持图卡 */
.support-section {
  background: linear-gradient(180deg, rgba(11, 17, 32, 0.5) 0%, rgba(7, 9, 19, 0.8) 100%);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  padding: 34px 30px;
  backdrop-filter: blur(10px);
}

.support-card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.support-card-header h3 {
  font-size: 1.32rem;
  color: #fff;
}

.app-pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 18px;
}

.app-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  color: var(--text-primary);
  font-weight: 500;
}

.app-pill svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* 套餐价格对比表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  backdrop-filter: blur(12px);
}

.pricing-card.featured {
  border-color: var(--cosmic-cyan);
  background: rgba(20, 32, 64, 0.88);
  box-shadow: 0 0 35px rgba(56, 189, 248, 0.28);
  transform: scale(1.03);
  z-index: 2;
}

.pricing-card:hover {
  border-color: var(--cosmic-cyan);
  transform: translateY(-5px);
}

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

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--btn-gradient);
  color: #fff;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.4);
}

.pricing-name {
  font-size: 1.38rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #fff;
}

.pricing-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.pricing-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--cosmic-cyan);
}

.price-amount {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  color: #fff;
}

.price-period {
  color: var(--text-muted);
  font-size: 0.92rem;
}

.pricing-features {
  list-style: none;
  margin-bottom: 30px;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.94rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

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

.pricing-table-container {
  margin-top: 55px;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glow);
  background: var(--bg-card);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 650px;
}

.comparison-table caption {
  caption-side: top;
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  padding: 18px 24px;
  background: rgba(255, 255, 255, 0.03);
  text-align: left;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.comparison-table th, .comparison-table td {
  padding: 16px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.95rem;
}

.comparison-table th {
  background: rgba(255, 255, 255, 0.04);
  color: var(--cosmic-cyan);
  font-weight: 600;
}

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

/* 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-rating {
  display: flex;
  gap: 4px;
  color: var(--cosmic-gold);
  margin-bottom: 14px;
}

.review-content {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

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

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--cosmic-purple), var(--cosmic-blue));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
}

.author-name {
  font-weight: 600;
  font-size: 0.96rem;
  color: #fff;
}

.author-role {
  font-size: 0.84rem;
  color: var(--text-muted);
}

/* FAQ 常见问题解答 - 默认展开 */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.25s ease;
}

.faq-item:hover {
  border-color: var(--border-glow-hover);
}

.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-icon-indicator {
  width: 22px;
  height: 22px;
  color: var(--cosmic-cyan);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

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

.faq-body {
  padding: 0 24px 22px 24px;
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.75;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 6px;
  padding-top: 14px;
}

/* 页脚 - 严格只保留四个标题与链接 */
.site-footer {
  background: #04060a;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 50px 0 35px;
  text-align: center;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 1.02rem;
  font-weight: 500;
  transition: color 0.2s ease;
  padding: 8px 12px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.footer-link:hover {
  color: var(--cosmic-cyan);
}

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

/* 文章详情页与知识科普页专属样式 */
.article-container {
  max-width: 860px;
  margin: 40px auto 80px;
  padding: 40px 36px;
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-card);
}

.article-header {
  margin-bottom: 35px;
  padding-bottom: 25px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.article-title {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.35;
  color: #fff;
  margin-bottom: 16px;
}

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

.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-content h2 {
  font-size: 1.55rem;
  color: #fff;
  margin: 36px 0 16px;
  border-left: 4px solid var(--cosmic-cyan);
  padding-left: 14px;
}

.article-content h3 {
  font-size: 1.25rem;
  color: #fff;
  margin: 26px 0 12px;
}

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

.article-content ul, .article-content ol {
  margin-bottom: 22px;
  padding-left: 24px;
}

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

.article-content a {
  color: var(--cosmic-cyan);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.article-content a:hover {
  color: #fff;
}

.article-cta-box {
  margin: 40px 0;
  padding: 30px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(56, 189, 248, 0.15));
  border: 1px solid var(--border-glow-hover);
  border-radius: var(--radius-md);
  text-align: center;
}

/* 知识科普目录列表 */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: 50px;
}

.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s ease;
  text-decoration: none;
}

.knowledge-card:hover {
  border-color: var(--cosmic-cyan);
  transform: translateY(-4px);
  box-shadow: 0 10px 24px rgba(56, 189, 248, 0.2);
}

.knowledge-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 10px;
  line-height: 1.4;
}

.knowledge-card:hover .knowledge-title {
  color: var(--cosmic-cyan);
}

.knowledge-summary {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 16px;
}

.knowledge-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.84rem;
  color: var(--text-muted);
}

/* 响应式媒体查询适配（360px, 390px, 768px, 1440px） */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.3rem;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 520px;
    margin: 0 auto;
  }
  .pricing-card.featured {
    transform: none;
  }
  .pricing-card.featured:hover {
    transform: translateY(-5px);
  }
  .support-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
    max-width: 520px;
    margin: 0 auto;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .knowledge-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }
  .site-header {
    height: auto;
    padding: 12px 0;
  }
  .header-inner {
    flex-direction: column;
    gap: 12px;
  }
  .nav-menu {
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .hero-section {
    padding: 50px 0 40px;
  }
  .hero-title {
    font-size: 1.95rem;
  }
  .hero-desc {
    font-size: 1rem;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .article-container {
    padding: 24px 18px;
    margin: 20px auto 50px;
  }
  .article-title {
    font-size: 1.65rem;
  }
  .footer-nav {
    flex-direction: column;
    gap: 10px;
  }
}

@media (max-width: 390px) {
  .hero-title {
    font-size: 1.7rem;
  }
  .btn {
    width: 100%;
    padding: 12px 18px;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-stats {
    grid-template-columns: 1fr;
  }
}

/* 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;
  }
}