/* ==========================================================================
   青云梯 (QingYunTi) - 方案 C 视觉规范样式表
   色彩：黑色固定左侧导航 / 白色背景 / 粗黑大字 / 橙色 #FF641E / 蓝色 #123CB7
   风格：非对称 Hero、真实建筑摄影、斜切几何布局、四宫格、横向大数字套餐、手风琴 FAQ、蓝橙高对比 CTA
   ========================================================================== */

:root {
  --color-nav-bg: #111317;
  --color-nav-card: #181b22;
  --color-nav-border: #232731;
  --color-nav-text: #94a3b8;
  --color-nav-text-hover: #ffffff;
  
  --color-bg: #ffffff;
  --color-bg-subtle: #f8fafc;
  --color-bg-card: #ffffff;
  
  --color-text-title: #0b0f19;
  --color-text-main: #1e293b;
  --color-text-muted: #64748b;
  --color-text-subtle: #94a3b8;
  
  --color-orange: #FF641E;
  --color-orange-hover: #e05214;
  --color-orange-light: #fff4ed;
  --color-orange-glow: rgba(255, 100, 30, 0.15);
  
  --color-blue: #123CB7;
  --color-blue-hover: #0c2980;
  --color-blue-light: #eff4fe;
  --color-blue-glow: rgba(18, 60, 183, 0.12);
  
  --color-border: #e2e8f0;
  --color-border-subtle: #f1f5f9;
  --color-border-strong: #cbd5e1;
  
  --sidebar-width: 270px;
  --header-mobile-height: 64px;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 24px -4px rgba(15, 23, 42, 0.12);
  --shadow-xl: 0 20px 32px -8px rgba(15, 23, 42, 0.16);
  --shadow-orange: 0 8px 24px -4px rgba(255, 100, 30, 0.35);
  --shadow-blue: 0 8px 24px -4px rgba(18, 60, 183, 0.3);
  
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-main);
  background-color: var(--color-bg);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  display: flex;
  background-color: var(--color-bg);
  overflow-x: hidden;
}

img, svg {
  display: block;
  max-width: 100%;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ==========================================================================
   侧边栏与导航 (Fixed Sidebar / Mobile Drawer)
   ========================================================================== */

.app-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background-color: var(--color-nav-bg);
  border-right: 1px solid var(--color-nav-border);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 32px 22px;
  z-index: 100;
  overflow-y: auto;
  transition: var(--transition);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-nav-border);
}

.brand-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-blue) 0%, #1e4fd9 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px rgba(18, 60, 183, 0.4);
  position: relative;
}

.brand-icon::after {
  content: "";
  position: absolute;
  top: -2px;
  right: -2px;
  width: 8px;
  height: 8px;
  background: var(--color-orange);
  border-radius: 50%;
  border: 2px solid var(--color-nav-bg);
}

.brand-text-wrap {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.brand-tag {
  font-size: 0.72rem;
  color: var(--color-orange);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 2px;
}

.sidebar-nav {
  margin: 28px 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.nav-heading {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #4b5563;
  font-weight: 700;
  padding: 8px 12px 4px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 14px;
  border-radius: var(--radius-sm);
  color: var(--color-nav-text);
  font-size: 0.92rem;
  font-weight: 600;
  position: relative;
}

.nav-link:hover {
  color: var(--color-nav-text-hover);
  background-color: var(--color-nav-card);
}

.nav-link.active {
  color: #ffffff;
  background-color: rgba(18, 60, 183, 0.18);
  border-left: 3px solid var(--color-orange);
  font-weight: 700;
}

.nav-link svg {
  width: 18px;
  height: 18px;
  stroke-width: 2;
  opacity: 0.8;
}

.nav-link:hover svg,
.nav-link.active svg {
  opacity: 1;
  stroke: var(--color-orange);
}

.sidebar-footer {
  padding-top: 20px;
  border-top: 1px solid var(--color-nav-border);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.network-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background-color: var(--color-nav-card);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: #94a3b8;
  font-weight: 500;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10b981;
  box-shadow: 0 0 8px #10b981;
  animation: pulse-green 2s infinite;
}

@keyframes pulse-green {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.sidebar-cta-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px;
  background: linear-gradient(135deg, var(--color-orange) 0%, #ff7d42 100%);
  color: #ffffff;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 700;
  text-align: center;
  box-shadow: var(--shadow-orange);
}

.sidebar-cta-btn:hover {
  background: var(--color-orange-hover);
  transform: translateY(-1px);
}

/* 移动端导航头部与抽屉遮罩 */
.mobile-header {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-mobile-height);
  background-color: var(--color-nav-bg);
  border-bottom: 1px solid var(--color-nav-border);
  padding: 0 20px;
  align-items: center;
  justify-content: space-between;
  z-index: 90;
}

.mobile-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.mobile-toggle {
  width: 40px;
  height: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  background: var(--color-nav-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-nav-border);
}

.mobile-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: #ffffff;
  border-radius: 2px;
  transition: var(--transition);
}

.mobile-toggle.is-active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.mobile-toggle.is-active span:nth-child(2) {
  opacity: 0;
}
.mobile-toggle.is-active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  z-index: 95;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.drawer-overlay.is-active {
  opacity: 1;
  visibility: visible;
}

/* ==========================================================================
   页面主体排版 (Main Content Container)
   ========================================================================== */

.app-main {
  margin-left: var(--sidebar-width);
  flex: 1;
  min-width: 0;
  background-color: var(--color-bg);
  display: flex;
  flex-direction: column;
}

.content-section {
  padding: 80px 48px;
  max-width: 1280px;
  margin: 0 auto;
  width: 100%;
}

.section-header {
  margin-bottom: 48px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  background-color: var(--color-blue-light);
  color: var(--color-blue);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  transform: skewX(-8deg);
}

.section-tag span {
  transform: skewX(8deg);
}

.section-tag.tag-orange {
  background-color: var(--color-orange-light);
  color: var(--color-orange);
}

.section-title {
  font-size: 2.25rem;
  font-weight: 900;
  color: var(--color-text-title);
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 720px;
  margin-top: 12px;
  line-height: 1.65;
}

/* ==========================================================================
   模块 1：Hero 区域 (Asymmetric Hero with Real Architecture Photography)
   ========================================================================== */

.hero-section {
  padding: 72px 48px 88px;
  background: linear-gradient(180deg, #ffffff 0%, var(--color-bg-subtle) 100%);
  border-bottom: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
  max-width: 1280px;
  margin: 0 auto;
}

.hero-content {
  display: flex;
  flex-direction: column;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-orange);
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--color-text-title);
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
  width: fit-content;
}

.hero-h1 {
  font-size: 3rem;
  font-weight: 900;
  color: var(--color-text-title);
  line-height: 1.16;
  letter-spacing: -0.035em;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-blue);
  margin-bottom: 20px;
  letter-spacing: -0.01em;
}

.hero-desc {
  font-size: 1.08rem;
  color: var(--color-text-body);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 620px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}

.btn-primary-orange {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 32px;
  background-color: var(--color-orange);
  color: #ffffff;
  font-size: 1rem;
  font-weight: 800;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-orange);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.btn-primary-orange:hover {
  background-color: var(--color-orange-hover);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -4px rgba(255, 100, 30, 0.45);
}

.btn-secondary-blue {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 32px;
  background-color: #ffffff;
  color: var(--color-blue);
  border: 2px solid var(--color-blue);
  font-size: 1rem;
  font-weight: 800;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.btn-secondary-blue:hover {
  background-color: var(--color-blue);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-blue);
}

.hero-metrics {
  display: flex;
  gap: 28px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-number {
  font-size: 1.45rem;
  font-weight: 900;
  color: var(--color-text-title);
  letter-spacing: -0.02em;
}

.metric-label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

/* Hero 右侧斜切几何摄影视觉 */
.hero-visual {
  position: relative;
}

.architecture-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--color-border);
  background-color: #0b0f19;
}

.architecture-card img {
  width: 100%;
  height: 480px;
  object-fit: cover;
  display: block;
  transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.architecture-card:hover img {
  transform: scale(1.03);
}

.slant-corner-accent {
  position: absolute;
  top: 0;
  right: 0;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 80px 80px 0;
  border-color: transparent var(--color-orange) transparent transparent;
  z-index: 2;
}

.floating-telemetry {
  position: absolute;
  bottom: 24px;
  left: 24px;
  right: 24px;
  background: rgba(17, 19, 23, 0.88);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-left: 4px solid var(--color-blue);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-lg);
}

.telemetry-tag {
  font-size: 0.72rem;
  text-transform: uppercase;
  color: #94a3b8;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.telemetry-val {
  font-size: 1.05rem;
  font-weight: 800;
  color: #ffffff;
  margin-top: 2px;
}

.telemetry-status {
  padding: 4px 10px;
  background-color: rgba(16, 185, 129, 0.2);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   模块 2：四项信息优势 (Four-Grid Information Matrix)
   ========================================================================== */

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.advantage-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.advantage-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 0;
  background-color: var(--color-blue);
  transition: height 0.3s ease;
}

.advantage-card:hover {
  border-color: var(--color-blue);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.advantage-card:hover::before {
  height: 100%;
}

.advantage-card:nth-child(2n)::before {
  background-color: var(--color-orange);
}
.advantage-card:nth-child(2n):hover {
  border-color: var(--color-orange);
}

.advantage-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.advantage-icon-box {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background-color: var(--color-blue-light);
  color: var(--color-blue);
  display: flex;
  align-items: center;
  justify-content: center;
}

.advantage-card:nth-child(2n) .advantage-icon-box {
  background-color: var(--color-orange-light);
  color: var(--color-orange);
}

.advantage-num {
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--color-border-strong);
  letter-spacing: -0.03em;
}

.advantage-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 10px;
}

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

.advantage-specs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.spec-chip {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}

/* ==========================================================================
   模块 3：品牌与服务介绍 (Brand Identity & Service Introduction)
   ========================================================================== */

.intro-banner {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-left: 6px solid var(--color-blue);
  border-radius: var(--radius-md);
  padding: 44px 40px;
  margin-bottom: 40px;
}

.intro-disclaimer-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.intro-content-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.intro-text h3 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--color-text-title);
  line-height: 1.3;
  margin-bottom: 16px;
}

.intro-text p {
  font-size: 1rem;
  color: var(--color-text-body);
  line-height: 1.7;
  margin-bottom: 16px;
}

.intro-checklist {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 20px;
}

.intro-checklist li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--color-text-title);
}

.intro-checklist svg {
  color: var(--color-orange);
  flex-shrink: 0;
}

.intro-card-box {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-md);
  text-align: center;
}

.intro-box-stat {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--color-orange);
  line-height: 1;
  margin-bottom: 6px;
}

.intro-box-label {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-text-title);
  margin-bottom: 16px;
}

.intro-box-desc {
  font-size: 0.84rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   模块 4：四种使用场景 (Four Use Cases)
   ========================================================================== */

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

.scene-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.scene-card:hover {
  box-shadow: var(--shadow-xl);
  border-color: var(--color-blue);
  transform: translateY(-4px);
}

.scene-img-wrap {
  position: relative;
  height: 220px;
  overflow: hidden;
  background-color: #0b0f19;
}

.scene-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.scene-card:hover .scene-img-wrap img {
  transform: scale(1.05);
}

.scene-tag-badge {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(17, 19, 23, 0.85);
  backdrop-filter: blur(8px);
  color: #ffffff;
  padding: 4px 10px;
  font-size: 0.72rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.scene-body {
  padding: 28px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.scene-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 10px;
}

.scene-desc {
  font-size: 0.92rem;
  color: var(--color-text-body);
  line-height: 1.65;
  margin-bottom: 20px;
}

.scene-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--color-border-subtle);
}

.scene-features li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

.scene-features svg {
  color: var(--color-blue);
  width: 14px;
  height: 14px;
}

/* ==========================================================================
   模块 5：设备说明 (Devices & Cross-platform Compatibility)
   ========================================================================== */

.devices-wrapper {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px;
}

.devices-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.device-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: var(--transition);
}

.device-card:hover {
  border-color: var(--color-orange);
  box-shadow: var(--shadow-md);
}

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

.device-icon-box {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background-color: #f1f5f9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-title);
}

.device-name {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-text-title);
}

.device-support {
  font-size: 0.75rem;
  color: #10b981;
  font-weight: 700;
}

.device-clients {
  font-size: 0.84rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.device-clients strong {
  color: var(--color-text-title);
  font-weight: 700;
}

/* ==========================================================================
   模块 6：真实套餐专区 (Horizontal Large-Number Pricing Cards)
   ========================================================================== */

.pricing-notice-banner {
  background: rgba(18, 60, 183, 0.04);
  border: 1px dashed var(--color-blue);
  border-radius: var(--radius-md);
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 36px;
  flex-wrap: wrap;
  gap: 16px;
}

.notice-text {
  font-size: 0.88rem;
  color: var(--color-text-body);
}

.notice-text strong {
  color: var(--color-blue);
}

.pricing-grid {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.pricing-card-horizontal {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 36px;
  display: grid;
  grid-template-columns: 120px 1.4fr 1.6fr 200px;
  align-items: center;
  gap: 32px;
  transition: var(--transition);
  position: relative;
}

.pricing-card-horizontal:hover {
  border-color: var(--color-blue);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.pricing-card-horizontal.featured {
  border: 2px solid var(--color-orange);
  box-shadow: var(--shadow-orange);
}

.featured-ribbon {
  position: absolute;
  top: -12px;
  right: 32px;
  background-color: var(--color-orange);
  color: #ffffff;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 10px rgba(255, 100, 30, 0.3);
}

.large-index-num {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1;
  color: var(--color-blue);
  letter-spacing: -0.04em;
  opacity: 0.9;
}

.pricing-card-horizontal.featured .large-index-num {
  color: var(--color-orange);
}

.pricing-meta h3 {
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--color-text-title);
  margin-bottom: 6px;
}

.pricing-cycle {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

.pricing-specs-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.pricing-spec-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--color-text-body);
}

.pricing-spec-item svg {
  color: var(--color-blue);
  flex-shrink: 0;
}

.pricing-action-col {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 12px;
}

.official-verify-status {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--color-text-muted);
  background-color: var(--color-bg-subtle);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

.btn-plan-action {
  width: 100%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 20px;
  background-color: var(--color-blue);
  color: #ffffff;
  font-size: 0.92rem;
  font-weight: 800;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  text-align: center;
}

.btn-plan-action:hover {
  background-color: var(--color-blue-hover);
  box-shadow: var(--shadow-blue);
}

.pricing-card-horizontal.featured .btn-plan-action {
  background-color: var(--color-orange);
  box-shadow: var(--shadow-orange);
}

.pricing-card-horizontal.featured .btn-plan-action:hover {
  background-color: var(--color-orange-hover);
}

/* ==========================================================================
   模块 7：购买前 3 条常见问题 (Pre-Purchase FAQ Cards)
   ========================================================================== */

.prep-faq-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.prep-faq-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-top: 4px solid var(--color-orange);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
}

.prep-num {
  font-size: 0.82rem;
  font-weight: 800;
  color: var(--color-orange);
  margin-bottom: 12px;
  text-transform: uppercase;
}

.prep-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 12px;
  line-height: 1.4;
}

.prep-answer {
  font-size: 0.9rem;
  color: var(--color-text-body);
  line-height: 1.65;
}

/* ==========================================================================
   模块 8：7 条手风琴 FAQ (Accordion FAQ)
   ========================================================================== */

.faq-accordion-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 960px;
}

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

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

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 28px;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-text-title);
  text-align: left;
  gap: 20px;
}

.faq-toggle-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-bg-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-blue);
  flex-shrink: 0;
  transition: transform 0.3s ease;
}

.faq-item.is-active .faq-toggle-icon {
  transform: rotate(45deg);
  background-color: var(--color-orange);
  color: #ffffff;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1), padding 0.35s ease;
  background-color: #ffffff;
}

.faq-item.is-active .faq-answer {
  max-height: 400px;
  padding: 0 28px 24px;
  border-top: 1px solid var(--color-border-subtle);
}

.faq-answer p {
  font-size: 0.95rem;
  color: var(--color-text-body);
  line-height: 1.7;
  padding-top: 16px;
}

/* ==========================================================================
   模块 9：最终高对比蓝橙 CTA (Final High-contrast Blue-Orange CTA)
   ========================================================================== */

.cta-box-container {
  background: linear-gradient(135deg, var(--color-blue) 0%, #0d2a80 100%);
  border-radius: var(--radius-xl);
  padding: 64px 60px;
  color: #ffffff;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
  box-shadow: 0 24px 48px -12px rgba(18, 60, 183, 0.4);
  position: relative;
  overflow: hidden;
}

.cta-box-container::before {
  content: "";
  position: absolute;
  top: -50px;
  right: -50px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, rgba(255, 100, 30, 0.3) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.cta-content-left {
  position: relative;
  z-index: 2;
}

.cta-badge {
  display: inline-block;
  padding: 6px 14px;
  background-color: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
}

.cta-title {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 18px;
}

.cta-desc {
  font-size: 1.05rem;
  color: #dbeafe;
  line-height: 1.65;
  margin-bottom: 32px;
}

.cta-buttons-wrap {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-cta-orange {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  background-color: var(--color-orange);
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 900;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-orange);
  transition: var(--transition);
}

.btn-cta-orange:hover {
  background-color: var(--color-orange-hover);
  transform: translateY(-2px);
  box-shadow: 0 14px 32px -4px rgba(255, 100, 30, 0.5);
}

.btn-cta-ghost {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 32px;
  background-color: transparent;
  color: #ffffff;
  border: 2px solid rgba(255, 255, 255, 0.4);
  font-size: 1.05rem;
  font-weight: 800;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.btn-cta-ghost:hover {
  border-color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
}

.cta-image-right {
  position: relative;
  z-index: 2;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.3);
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.cta-image-right img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

/* ==========================================================================
   模块 10：页脚 (Footer with Full Navigation & Disclaimer)
   ========================================================================== */

.app-footer {
  background-color: #0b0d11;
  color: #94a3b8;
  padding: 64px 48px 36px;
  border-top: 1px solid #1a1e26;
  margin-top: auto;
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand h4 {
  font-size: 1.25rem;
  font-weight: 900;
  color: #ffffff;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.7;
  color: #64748b;
  margin-bottom: 20px;
}

.footer-col h5 {
  font-size: 0.95rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 18px;
  letter-spacing: -0.01em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 0.88rem;
  color: #94a3b8;
}

.footer-links a:hover {
  color: var(--color-orange);
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid #1a1e26;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: #64748b;
  flex-wrap: wrap;
  gap: 16px;
}

/* ==========================================================================
   知识库列表与文章详情专页样式 (Knowledge Base & Article Layout)
   ========================================================================== */

.article-header {
  padding: 48px 0 36px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 40px;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

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

.article-header h1 {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--color-text-title);
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.84rem;
  color: var(--color-text-muted);
  flex-wrap: wrap;
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 48px;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--color-text-main);
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin: 40px 0 16px;
  padding-left: 14px;
  border-left: 4px solid var(--color-orange);
  line-height: 1.3;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin: 28px 0 12px;
}

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

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

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

.article-callout {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-blue);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin: 28px 0;
  font-size: 0.95rem;
}

.article-callout strong {
  color: var(--color-blue);
}

.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.sidebar-box {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sidebar-box h4 {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.knowledge-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.knowledge-card:hover {
  border-color: var(--color-blue);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.knowledge-card-tag {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--color-orange);
  text-transform: uppercase;
  margin-bottom: 10px;
}

.knowledge-card-title {
  font-size: 1.18rem;
  font-weight: 800;
  color: var(--color-text-title);
  margin-bottom: 12px;
  line-height: 1.4;
}

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

.knowledge-card-link {
  font-size: 0.84rem;
  font-weight: 800;
  color: var(--color-blue);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.knowledge-card:hover .knowledge-card-link {
  color: var(--color-orange);
}

/* ==========================================================================
   响应式断点控制 (Responsive Breakpoints: Desktop, Tablet, Mobile)
   ========================================================================== */

@media (max-width: 1180px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .pricing-card-horizontal {
    grid-template-columns: 80px 1fr 1fr;
    gap: 20px;
  }
  .pricing-action-col {
    grid-column: 1 / -1;
    align-items: stretch;
  }
  .cta-box-container {
    grid-template-columns: 1fr;
    padding: 48px 36px;
  }
  .knowledge-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1024px) {
  .app-sidebar {
    transform: translateX(-100%);
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.5);
  }
  .app-sidebar.is-open {
    transform: translateX(0);
  }
  .mobile-header {
    display: flex;
  }
  .app-main {
    margin-left: 0;
    padding-top: var(--header-mobile-height);
  }
  .content-section {
    padding: 60px 24px;
  }
  .hero-section {
    padding: 48px 24px 64px;
  }
  .hero-h1 {
    font-size: 2.35rem;
  }
  .advantages-grid {
    grid-template-columns: 1fr;
  }
  .scenes-grid {
    grid-template-columns: 1fr;
  }
  .devices-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .prep-faq-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .hero-h1 {
    font-size: 1.85rem;
  }
  .hero-subtitle {
    font-size: 1.15rem;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .cta-title {
    font-size: 1.85rem;
  }
  .pricing-card-horizontal {
    grid-template-columns: 1fr;
    padding: 24px 20px;
  }
  .devices-grid {
    grid-template-columns: 1fr;
  }
  .knowledge-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .btn-primary-orange, .btn-secondary-blue, .btn-cta-orange, .btn-cta-ghost {
    width: 100%;
    text-align: center;
  }
  .hero-metrics {
    flex-wrap: wrap;
    gap: 16px;
  }
}