/* ===================================================================
   青云梯 QingYunTi - 原生高性能 CSS 样式表
   零外部依赖 | 极简秒开 | 全响应式适配
   =================================================================== */

:root {
  --bg-primary: #030712;
  --bg-secondary: #0b0f1e;
  --bg-card: rgba(13, 19, 36, 0.78);
  --bg-card-hover: rgba(22, 31, 56, 0.88);
  --border-color: rgba(99, 102, 241, 0.16);
  --border-focus: rgba(56, 189, 248, 0.45);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --accent-cyan: #38bdf8;
  --accent-blue: #3b82f6;
  --accent-indigo: #818cf8;
  --accent-green: #10b981;
  --accent-gold: #f59e0b;
  --accent-purple: #c084fc;
  
  --gradient-brand: linear-gradient(135deg, #38bdf8 0%, #6366f1 50%, #c084fc 100%);
  --gradient-btn: linear-gradient(135deg, #0284c7 0%, #4f46e5 100%);
  --gradient-btn-hover: linear-gradient(135deg, #0ea5e9 0%, #6366f1 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.2) 0%, transparent 70%);
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-glow: 0 0 25px rgba(99, 102, 241, 0.4);
  --shadow-glow-cyan: 0 0 20px rgba(56, 189, 248, 0.4);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --max-w: 1200px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 88px; /* 解决固定页眉遮挡锚点标题 */
}

/* 锚点目标顶部留白，防止被 72px 悬浮导航遮挡 */
[id] {
  scroll-margin-top: 88px;
}

/* 无障碍：跳转到主要内容 (键盘 Tab 键触发显现) */
.skip-to-content {
  position: absolute;
  top: -100px;
  left: 24px;
  background: var(--gradient-btn);
  color: #ffffff;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.95rem;
  z-index: 99999;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
  transition: top 0.2s ease;
}

.skip-to-content:focus {
  top: 16px;
  outline: 3px solid var(--accent-cyan);
}

/* 全局交互元素键盘焦点环样式 */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent-cyan) !important;
  outline-offset: 3px !important;
  border-radius: 4px;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  background-image: 
    radial-gradient(ellipse at 50% -5%, rgba(99, 102, 241, 0.25) 0%, transparent 55%),
    radial-gradient(ellipse at 88% 28%, rgba(6, 182, 212, 0.14) 0%, transparent 45%),
    radial-gradient(ellipse at 12% 62%, rgba(168, 85, 247, 0.16) 0%, transparent 50%),
    radial-gradient(ellipse at 82% 82%, rgba(37, 99, 235, 0.14) 0%, transparent 42%),
    radial-gradient(2px 2px at 20px 30px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(2px 2px at 90px 140px, #38bdf8, rgba(0,0,0,0)),
    radial-gradient(1.5px 1.5px at 180px 70px, #c084fc, rgba(0,0,0,0)),
    radial-gradient(2px 2px at 320px 220px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(1px 1px at 420px 110px, #818cf8, rgba(0,0,0,0)),
    radial-gradient(2px 2px at 560px 290px, #38bdf8, rgba(0,0,0,0)),
    radial-gradient(1.5px 1.5px at 700px 160px, #ffffff, rgba(0,0,0,0)),
    radial-gradient(2px 2px at 850px 250px, #c084fc, rgba(0,0,0,0));
  background-repeat: repeat;
  background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 550px 550px, 480px 480px, 600px 600px, 520px 520px, 400px 400px, 650px 650px, 580px 580px, 700px 700px;
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

img, svg {
  display: block;
}

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

.section {
  padding-top: 80px;
  padding-bottom: 80px;
  position: relative;
}

/* 标题通用样式 */
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 54px auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.25);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 16px;
  letter-spacing: 0.5px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

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

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

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 28px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all 0.25s ease;
  min-height: 48px; /* 适合手指点击 */
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-btn);
  color: #ffffff;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  background: var(--gradient-btn-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-block {
  width: 100%;
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
  font-weight: 700;
}

/* ================= 导航条 (Header) ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 15, 29, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.brand-logo svg {
  width: 32px;
  height: 32px;
  filter: drop-shadow(0 0 10px rgba(6, 182, 212, 0.5));
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-link:hover {
  color: var(--accent-cyan);
}

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

/* ================= 主视觉区 (Hero) ================= */
.hero-section {
  padding-top: 100px;
  padding-bottom: 90px;
  text-align: left; /* 主视觉区居左 */
  position: relative;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 24px;
  margin-left: 0;
}

.hero-pill-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

/* ================= 主视觉区栅格布局 (Hero Grid: 左侧大标题文案与CTA，右侧特大太空穿梭火箭) ================= */
.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.85fr;
  align-items: center;
  gap: 48px;
  margin-bottom: 56px;
  width: 100%;
}

.hero-content {
  text-align: left;
}

.hero-title {
  font-size: 3.3rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -1.2px;
  text-align: left;
  margin: 0 0 24px 0;
}

.hero-title-text {
  text-align: left;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 660px;
  margin: 0 0 36px 0;
  line-height: 1.68;
  text-align: left;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 16px;
  margin-bottom: 0;
  flex-wrap: wrap;
}

/* 右侧太空穿梭特大视觉展示区 (直接定位于屏幕右半侧空旷区) */
.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  min-height: 380px;
}

.hero-visual::before {
  content: "";
  position: absolute;
  width: 380px;
  height: 380px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.24) 0%, rgba(99, 102, 241, 0.16) 45%, rgba(168, 85, 247, 0.08) 65%, transparent 75%);
  border-radius: 50%;
  filter: blur(36px);
  pointer-events: none;
  animation: cosmicAuraPulse 4s ease-in-out infinite alternate;
}

@keyframes cosmicAuraPulse {
  0% {
    transform: scale(0.9);
    opacity: 0.55;
  }
  100% {
    transform: scale(1.15);
    opacity: 0.95;
  }
}

.hero-cosmic-rocket,
.hero-title-cosmic-anim {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 320px; /* 特大号 320px，宏伟饱满填补右侧视觉空白 */
  height: 320px;
  flex-shrink: 0;
  animation: cosmicLevitate 3.8s ease-in-out infinite;
  filter: drop-shadow(0 0 35px rgba(56, 189, 248, 0.85)) drop-shadow(0 0 70px rgba(99, 102, 241, 0.5));
}

.cosmic-rocket-svg {
  width: 100%;
  height: 100%;
}

.rocket-body-group {
  animation: rocketPulse 2.2s ease-in-out infinite alternate;
  transform-origin: center bottom;
}

.rocket-flame {
  animation: thrustFlame 0.75s ease-in-out infinite alternate;
  transform-origin: top center;
}

.rocket-orbit-ring {
  animation: orbitSpin 14s linear infinite;
  transform-origin: 50px 46px;
}

@keyframes cosmicLevitate {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }
  50% {
    transform: translateY(-12px) rotate(4deg);
  }
}

@keyframes rocketPulse {
  0% {
    transform: scale(0.97);
  }
  100% {
    transform: scale(1.03);
  }
}

@keyframes thrustFlame {
  0% {
    transform: scaleY(0.8);
    opacity: 0.75;
  }
  100% {
    transform: scaleY(1.35);
    opacity: 1;
    filter: drop-shadow(0 0 12px #38bdf8);
  }
}

@keyframes orbitSpin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* 信任指标栏 */
.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1000px;
  margin: 0 auto;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
}

.metric-item {
  text-align: center;
  border-right: 1px solid var(--border-color);
}

.metric-item:last-child {
  border-right: none;
}

.metric-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.2;
  margin-bottom: 4px;
}

.metric-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ================= 核心优势 (Core Advantages) ================= */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.adv-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
}

.adv-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.adv-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

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

.adv-icon-wrap {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--accent-cyan);
}

.adv-icon-wrap svg {
  width: 32px;
  height: 32px;
}

.adv-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.adv-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
}

.adv-feature-list {
  list-style: none;
  border-top: 1px solid var(--border-color);
  padding-top: 18px;
}

.adv-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-main);
  margin-bottom: 10px;
}

.adv-feature-item:last-child {
  margin-bottom: 0;
}

.adv-feature-item svg {
  width: 16px;
  height: 16px;
  color: var(--accent-green);
  flex-shrink: 0;
}

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

.media-ai-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  backdrop-filter: blur(10px);
}

.media-ai-card-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.media-ai-badge {
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
}

.badge-ai {
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge-stream {
  background: rgba(239, 68, 68, 0.15);
  color: #fca5a5;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.media-ai-title {
  font-size: 1.4rem;
  font-weight: 700;
}

.media-ai-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.apps-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.app-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.app-item:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.2);
}

.app-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.app-info {
  flex-grow: 1;
  min-width: 0;
}

.app-name {
  font-size: 0.92rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.app-status {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  color: var(--accent-green);
}

.app-status-dot {
  width: 6px;
  height: 6px;
  background: var(--accent-green);
  border-radius: 50%;
}

/* ================= 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-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.pricing-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.pricing-card.popular {
  border-color: rgba(59, 130, 246, 0.6);
  box-shadow: 0 0 30px rgba(37, 99, 235, 0.2);
  background: linear-gradient(180deg, rgba(30, 58, 138, 0.3) 0%, rgba(17, 24, 39, 0.8) 100%);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-brand);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 18px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  box-shadow: var(--shadow-glow-cyan);
}

.pricing-head {
  text-align: center;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.plan-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 4px;
}

.currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.price-number {
  font-size: 3.2rem;
  font-weight: 900;
  line-height: 1;
  color: var(--text-main);
  letter-spacing: -1px;
}

.price-unit {
  font-size: 0.95rem;
  color: var(--text-dim);
}

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

.pricing-feature-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.95rem;
  color: var(--text-main);
  margin-bottom: 14px;
}

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

.feature-highlight {
  font-weight: 600;
  color: var(--accent-cyan);
}

.pricing-note {
  text-align: center;
  margin-top: 36px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ================= 用户评价 (Testimonials) ================= */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.testi-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;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.testi-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 255, 255, 0.2);
}

.testi-stars {
  display: flex;
  gap: 4px;
  margin-bottom: 14px;
  color: var(--accent-gold);
}

.testi-stars svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.testi-text {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.testi-author {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1e293b, #334155);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--accent-cyan);
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.95rem;
}

.author-name {
  font-size: 0.92rem;
  font-weight: 600;
}

.author-role {
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* ================= 常见问题 (FAQ 6个) ================= */
.faq-wrap {
  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: border-color 0.25s ease;
}

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.18);
}

.faq-item[open] {
  border-color: var(--border-focus);
}

.faq-question {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  list-style: none; /* 去除原生三角形 */
}

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

.faq-icon {
  width: 20px;
  height: 20px;
  color: var(--accent-cyan);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

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

.faq-answer {
  padding: 0 24px 22px 24px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  border-top: 1px dashed rgba(255, 255, 255, 0.06);
  padding-top: 16px;
}

/* ================= 底部转化条 (Bottom CTA Banner) ================= */
.bottom-cta-banner {
  background: linear-gradient(135deg, rgba(30, 58, 138, 0.4) 0%, rgba(15, 23, 42, 0.9) 100%);
  border: 1px solid rgba(59, 130, 246, 0.3);
  border-radius: var(--radius-lg);
  padding: 50px 40px;
  text-align: center;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
  margin-top: 40px;
}

.bottom-cta-title {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.bottom-cta-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 30px auto;
}

/* ================= 页脚 (Footer 严格按要求 仅4个标题) ================= */
.site-footer {
  border-top: 1px solid var(--border-color);
  background: #070a14;
  padding: 50px 0 35px 0;
  margin-top: 80px;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  list-style: none;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-nav-link {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: all 0.2s ease;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
}

.footer-nav-link:hover {
  color: var(--accent-cyan);
  background: rgba(255, 255, 255, 0.05);
}

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

/* ================= 子页面通用排版样式 (Subpages) ================= */
.page-container {
  max-width: 860px;
  margin: 50px auto 80px auto;
  padding: 40px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
}

.page-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.page-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.page-date {
  font-size: 0.88rem;
  color: var(--text-dim);
}

.page-content h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent-cyan);
  margin-top: 36px;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-content p {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.page-content ul, .page-content ol {
  margin-left: 24px;
  margin-bottom: 20px;
  color: var(--text-muted);
  line-height: 1.8;
}

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

.back-to-home {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 24px;
  transition: transform 0.2s ease;
}

.back-to-home:hover {
  transform: translateX(-4px);
}

/* ================= 响应式媒体查询 (@media 移动端适配) ================= */

/* 平板与小型笔记本 (<= 1024px) */
@media screen and (max-width: 1024px) {
  .hero-title {
    font-size: 2.8rem;
  }
  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
  .pricing-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-metrics {
    grid-template-columns: repeat(2, 1fr);
    row-gap: 20px;
  }
  .metric-item:nth-child(2) {
    border-right: none;
  }
}

/* 手机端核心适配 (<= 768px 单栏显示) */
@media screen and (max-width: 768px) {
  .section {
    padding-top: 50px;
    padding-bottom: 50px;
  }

  .nav-wrapper {
    height: 64px;
  }

  .nav-menu {
    display: none; /* 移动端精简顶部导航，突出立即注册 CTA */
  }

  .hero-section {
    padding-top: 50px;
    padding-bottom: 50px;
  }

  .hero-title {
    font-size: 2.1rem;
    line-height: 1.25;
    letter-spacing: -0.5px;
  }

  .hero-subtitle {
    font-size: 1.02rem;
    margin-bottom: 30px;
  }

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

  .hero-cta-group .btn {
    width: 100%;
    min-height: 52px; /* 移动端大尺寸触控 */
  }

  /* 核心优势单栏 */
  .advantages-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  /* 流媒体与 AI 支持图卡单栏 */
  .media-ai-container {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .apps-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  /* 价格对比单栏 */
  .pricing-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .pricing-card.popular {
    transform: none;
  }

  /* 评价单栏 */
  .testimonials-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 信任数据统计 */
  .hero-metrics {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    padding: 16px;
  }

  .metric-item {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 12px;
  }

  .metric-item:nth-last-child(-n+2) {
    border-bottom: none;
    padding-bottom: 0;
  }

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

  .bottom-cta-banner {
    padding: 36px 20px;
  }

  .bottom-cta-title {
    font-size: 1.6rem;
  }

  /* 页脚四项链接响应式换行对齐 */
  .footer-nav {
    gap: 16px;
    flex-direction: column;
    align-items: center;
  }

  .footer-nav-link {
    font-size: 1.05rem;
    display: block;
    width: 100%;
    text-align: center;
    padding: 10px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
  }

  .page-container {
    margin: 20px 14px 50px 14px;
    padding: 24px 18px;
  }

  .page-title {
    font-size: 1.7rem;
  }
}

/* 超小屏幕手机 (<= 400px) */
@media screen and (max-width: 400px) {
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-metrics {
    grid-template-columns: 1fr;
  }
  .metric-item {
    border-bottom: 1px solid var(--border-color);
  }
  .metric-item:last-child {
    border-bottom: none;
  }
}


/* ================= 导航高亮与移动端快捷导航栏 ================= */
.nav-highlight {
  color: var(--accent-cyan) !important;
  font-weight: 600;
  position: relative;
}

.mobile-nav-bar {
  display: none;
  background: rgba(11, 17, 33, 0.95);
  border-top: 1px solid var(--border-color);
  padding: 8px 0;
}

.mobile-nav-scroll {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  white-space: nowrap;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.mobile-nav-scroll::-webkit-scrollbar {
  display: none;
}

.mobile-nav-pill {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
  flex-shrink: 0;
}

.mobile-nav-pill.active-pill {
  background: rgba(6, 182, 212, 0.15);
  border-color: rgba(6, 182, 212, 0.4);
  color: var(--accent-cyan);
  font-weight: 600;
}

@media screen and (max-width: 768px) {
  .mobile-nav-bar {
    display: block;
  }
}


/* ================= SEO 文章与知识库卡片样式 ================= */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 36px;
}

.article-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;
  transition: all 0.25s ease;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

.article-tag-list {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.article-tag-badge {
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.25);
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.45;
  margin-bottom: 12px;
  color: var(--text-main);
  transition: color 0.2s ease;
}

.article-card:hover .article-card-title {
  color: var(--accent-cyan);
}

.article-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
  font-size: 0.82rem;
  color: var(--text-dim);
}

.read-more-link {
  color: var(--accent-cyan);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 单篇文章排版 */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 20px;
}

.breadcrumbs a {
  color: var(--text-muted);
  transition: color 0.2s ease;
}

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

.article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 20px;
  margin-bottom: 28px;
}

.article-main-title {
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 14px;
}

.article-meta-info {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-dim);
  flex-wrap: wrap;
}

.article-body {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.85;
}

.article-body h2 {
  font-size: 1.4rem;
  color: var(--text-main);
  margin-top: 36px;
  margin-bottom: 14px;
  border-left: 4px solid var(--accent-cyan);
  padding-left: 12px;
}

.article-body h3 {
  font-size: 1.15rem;
  color: var(--accent-cyan);
  margin-top: 24px;
  margin-bottom: 10px;
}

.article-body p {
  margin-bottom: 16px;
}

.article-body ul, .article-body ol {
  margin-left: 24px;
  margin-bottom: 20px;
}

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

.article-body blockquote {
  border-left: 4px solid var(--accent-blue);
  background: rgba(59, 130, 246, 0.08);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
  font-style: italic;
  color: #cbd5e1;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(30, 58, 138, 0.35) 0%, rgba(15, 23, 42, 0.85) 100%);
  border: 1px solid rgba(59, 130, 246, 0.35);
  border-radius: var(--radius-md);
  padding: 28px;
  text-align: center;
  margin: 40px 0;
}

.article-cta-box h3 {
  font-size: 1.35rem;
  color: #fff;
  margin-bottom: 10px;
}

.article-cta-box p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

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

@media screen and (max-width: 768px) {
  .article-grid {
    grid-template-columns: 1fr;
  }
  .article-main-title {
    font-size: 1.65rem;
  }
}


/* ================= 太空主题背景与流星群动效 (Cosmic Meteor Shower) ================= */
.space-sky {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.meteor {
  position: absolute;
  top: -80px;
  width: 170px;
  height: 2px;
  background: linear-gradient(90deg, #ffffff, rgba(56, 189, 248, 0.9) 35%, rgba(129, 140, 248, 0.4) 70%, transparent);
  transform: rotate(-35deg);
  opacity: 0;
  border-radius: 999px;
  filter: drop-shadow(0 0 6px #38bdf8);
  animation: meteorFall 6s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.meteor::before {
  content: "";
  position: absolute;
  left: 0;
  top: -2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 0 10px 3px #38bdf8, 0 0 20px 6px rgba(168, 85, 247, 0.7);
}

.meteor-1  { left: 6%;  animation-delay: 0s;   animation-duration: 4.2s; width: 180px; }
.meteor-2  { left: 18%; animation-delay: 1.1s; animation-duration: 5.4s; width: 230px; }
.meteor-3  { left: 32%; animation-delay: 2.8s; animation-duration: 4.6s; width: 160px; }
.meteor-4  { left: 45%; animation-delay: 0.5s; animation-duration: 5.1s; width: 210px; }
.meteor-5  { left: 58%; animation-delay: 2.2s; animation-duration: 3.9s; width: 250px; }
.meteor-6  { left: 72%; animation-delay: 3.7s; animation-duration: 5.8s; width: 190px; }
.meteor-7  { left: 85%; animation-delay: 1.6s; animation-duration: 4.8s; width: 240px; }
.meteor-8  { left: 96%; animation-delay: 3.1s; animation-duration: 4.3s; width: 170px; }
.meteor-9  { left: 12%; animation-delay: 4.2s; animation-duration: 5.0s; width: 220px; }
.meteor-10 { left: 24%; animation-delay: 0.2s; animation-duration: 3.8s; width: 260px; }
.meteor-11 { left: 39%; animation-delay: 1.9s; animation-duration: 5.3s; width: 180px; }
.meteor-12 { left: 52%; animation-delay: 4.6s; animation-duration: 4.4s; width: 230px; }
.meteor-13 { left: 65%; animation-delay: 0.8s; animation-duration: 3.6s; width: 210px; }
.meteor-14 { left: 79%; animation-delay: 2.5s; animation-duration: 5.5s; width: 240px; }
.meteor-15 { left: 90%; animation-delay: 4.9s; animation-duration: 4.1s; width: 190px; }
.meteor-16 { left: 3%;  animation-delay: 2.1s; animation-duration: 4.7s; width: 200px; }
.meteor-17 { left: 28%; animation-delay: 3.5s; animation-duration: 3.7s; width: 250px; }
.meteor-18 { left: 42%; animation-delay: 5.2s; animation-duration: 5.6s; width: 170px; }
.meteor-19 { left: 62%; animation-delay: 1.4s; animation-duration: 4.5s; width: 220px; }
.meteor-20 { left: 83%; animation-delay: 3.9s; animation-duration: 4.9s; width: 260px; }

@keyframes meteorFall {
  0% {
    opacity: 0;
    transform: translate3d(0, 0, 0) rotate(-35deg) scale(0.6);
  }
  15% {
    opacity: 1;
  }
  65% {
    opacity: 1;
  }
  100% {
    opacity: 0;
    transform: translate3d(-1100px, 1200px, 0) rotate(-35deg) scale(1.15);
  }
}

/* 保证主内容和头部在太空流星背景上方 */
.site-header, main, .site-footer {
  position: relative;
  z-index: 1;
}

/* 响应式尺寸适配 */
@media screen and (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 32px;
  }
  .hero-title {
    font-size: 2.7rem;
  }
  .hero-cosmic-rocket,
  .hero-title-cosmic-anim {
    width: 260px;
    height: 260px;
  }
}

@media screen and (max-width: 768px) {
  .hero-section {
    padding-top: 50px;
    padding-bottom: 50px;
    text-align: left;
  }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 36px;
    margin-bottom: 40px;
  }
  .hero-visual {
    min-height: auto;
  }
  .hero-title {
    font-size: 2rem;
    line-height: 1.22;
  }
  .hero-cosmic-rocket,
  .hero-title-cosmic-anim {
    width: 200px;
    height: 200px;
  }
}

@media screen and (max-width: 440px) {
  .hero-title {
    font-size: 1.65rem;
  }
  .hero-cosmic-rocket,
  .hero-title-cosmic-anim {
    width: 160px;
    height: 160px;
  }
}

/* ================= 无障碍：减弱动画偏好 (prefers-reduced-motion) ================= */
@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;
  }
  .meteor {
    display: none !important;
  }
  .hero-cosmic-rocket,
  .hero-title-cosmic-anim,
  .rocket-orbit-ring,
  .rocket-flame,
  .hero-visual::before {
    animation: none !important;
    transform: none !important;
  }
}