/* ==========================================================================
   轻语机场 (qingyujc.homes) 官方网站样式表
   框架: 03 流体玻璃 / 极光推进 (Aurora Liquid Glass) 纵向无障碍自然滚动
   特性: 极光流体呼吸动画、磨砂玻璃浮岛、蓝图网格卡片、故障决策树展开、全端响应式
   ========================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* 极光与流体玻璃主色调 */
  --bg-dark: #070c18;
  --bg-darker: #040812;
  --bg-surface: rgba(13, 22, 44, 0.7);
  --bg-card: rgba(255, 255, 255, 0.04);
  --bg-card-hover: rgba(255, 255, 255, 0.07);
  --border-glass: rgba(255, 255, 255, 0.12);
  --border-glass-hover: rgba(56, 189, 248, 0.4);

  /* 极光色彩系统 */
  --aurora-cyan: #00f2fe;
  --aurora-blue: #38bdf8;
  --aurora-indigo: #6366f1;
  --aurora-purple: #a855f7;
  --aurora-glow: rgba(56, 189, 248, 0.25);

  /* 文字颜色 */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-accent: #38bdf8;

  /* 交互主色 */
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-gradient: linear-gradient(135deg, #00f2fe 0%, #0284c7 50%, #4f46e5 100%);
  --cta-btn-bg: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  --cta-btn-hover: linear-gradient(135deg, #0369a1 0%, #1d4ed8 100%);

  /* 阴影与模糊 */
  --glass-blur: blur(20px);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --glass-glow: 0 0 25px rgba(56, 189, 248, 0.2);

  /* 尺寸 */
  --container-max: 1200px;
  --nav-height: 72px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
}

/* 基础重置与无障碍支持 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body {
  position: relative;
  min-height: 100vh;
  background-color: var(--bg-dark);
  overflow-x: hidden;
  color: var(--text-primary);
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.2s ease;
}

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

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

/* 极光背景画布层 (Aurora Fluid Background) */
.aurora-bg-wrap {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  overflow: hidden;
  pointer-events: none;
  background: radial-gradient(circle at 50% 15%, #0f1d3d 0%, #070c18 60%, #03060c 100%);
}

.aurora-mesh {
  position: absolute;
  width: 150vw;
  height: 150vh;
  top: -25vh;
  left: -25vw;
  filter: blur(80px);
  opacity: 0.45;
  animation: auroraFlow 22s ease-in-out infinite alternate;
}

.aurora-blob {
  position: absolute;
  border-radius: 50%;
  mix-blend-mode: screen;
}

.aurora-blob-1 {
  width: 60vw;
  height: 60vh;
  top: 10%;
  left: 15%;
  background: radial-gradient(circle, rgba(0, 242, 254, 0.7) 0%, rgba(37, 99, 235, 0.1) 70%, transparent 100%);
}

.aurora-blob-2 {
  width: 55vw;
  height: 55vh;
  top: 25%;
  right: 10%;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.65) 0%, rgba(99, 102, 241, 0.1) 70%, transparent 100%);
}

.aurora-blob-3 {
  width: 50vw;
  height: 50vh;
  bottom: 10%;
  left: 30%;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.6) 0%, rgba(14, 165, 233, 0.15) 70%, transparent 100%);
}

.aurora-grid-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at 50% 30%, rgba(0, 0, 0, 0.9) 0%, rgba(0, 0, 0, 0.1) 85%);
}

@keyframes auroraFlow {
  0% {
    transform: rotate(0deg) scale(1) translate(0, 0);
  }
  50% {
    transform: rotate(10deg) scale(1.12) translate(30px, -20px);
  }
  100% {
    transform: rotate(-8deg) scale(0.95) translate(-30px, 30px);
  }
}

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

/* 通用区块排版 */
.section {
  position: relative;
  padding: 96px 0;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 9999px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--aurora-cyan);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
  backdrop-filter: var(--glass-blur);
}

.section-tag-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--aurora-cyan);
  box-shadow: 0 0 8px var(--aurora-cyan);
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.3); }
}

.section-title {
  font-size: clamp(2rem, 3.8vw, 2.75rem);
  font-weight: 800;
  line-height: 1.25;
  color: #ffffff;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  color: var(--text-secondary);
  max-width: 680px;
  line-height: 1.7;
  margin-bottom: 48px;
}

.text-center {
  text-align: center;
}
.text-center .section-desc {
  margin-left: auto;
  margin-right: auto;
}

/* 玻璃卡片基类 */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.glass-panel:hover {
  border-color: var(--border-glass-hover);
  box-shadow: var(--glass-shadow), var(--glass-glow);
}

/* ==========================================================================
   1. 顶部导航栏 (Navbar)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 100;
  background: rgba(7, 12, 24, 0.75);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background 0.3s ease, border-color 0.3s ease;
}

.site-header.scrolled {
  background: rgba(4, 8, 18, 0.92);
  border-bottom: 1px solid rgba(56, 189, 248, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo-icon {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  transition: transform 0.3s ease;
}

.brand-logo-wrap:hover .brand-logo-icon {
  transform: rotate(-6deg) scale(1.08);
}

.brand-name-group {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.1875rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, #ffffff 30%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-domain {
  font-size: 0.6875rem;
  font-family: var(--font-mono);
  color: var(--aurora-blue);
  letter-spacing: 0.05em;
  opacity: 0.9;
}

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

.nav-link {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  font-weight: 500;
  padding: 6px 2px;
  position: relative;
  transition: color 0.2s ease;
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--aurora-cyan);
  transition: width 0.25s ease;
  border-radius: 2px;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  background: var(--cta-btn-bg);
  color: #ffffff;
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary:hover {
  background: var(--cta-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(2, 132, 199, 0.6);
  color: #ffffff;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--radius-md);
  backdrop-filter: var(--glass-blur);
  transition: all 0.25s ease;
  white-space: nowrap;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(56, 189, 248, 0.4);
  color: #ffffff;
  transform: translateY(-2px);
}

.mobile-menu-btn {
  display: none;
  padding: 8px;
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.05);
}

/* 移动端抽屉默认完全隐藏，桌面端绝对不显示 */
.mobile-drawer {
  display: none !important;
}

/* ==========================================================================
   2. 首屏 (Hero Section)
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 100px 0 80px;
  min-height: calc(90vh - var(--nav-height));
  display: flex;
  align-items: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}

.hero-badge-wrap {
  margin-bottom: 24px;
}

.hero-announcement {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 18px 6px 12px;
  border-radius: 9999px;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.3);
  backdrop-filter: var(--glass-blur);
  color: var(--text-primary);
  font-size: 0.875rem;
}

.hero-announcement-tag {
  background: linear-gradient(135deg, var(--aurora-cyan), #0284c7);
  color: #030a17;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 9999px;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: clamp(2.35rem, 4.4vw, 3.75rem);
  font-weight: 850;
  line-height: 1.18;
  letter-spacing: -0.03em;
  color: #ffffff;
  margin-bottom: 24px;
}

.hero-title-gradient {
  background: linear-gradient(135deg, #00f2fe 10%, #38bdf8 50%, #c084fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.0625rem, 1.4vw, 1.1875rem);
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 580px;
}

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

.hero-cta-main {
  padding: 14px 34px;
  font-size: 1.0625rem;
  border-radius: var(--radius-md);
  box-shadow: 0 8px 24px rgba(2, 132, 199, 0.45);
}

.hero-cta-sub {
  padding: 14px 28px;
  font-size: 1.0625rem;
}

.hero-trust-badges {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-trust-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.hero-trust-icon {
  color: var(--aurora-cyan);
  font-size: 1rem;
}

/* 首屏右侧流体玻璃交互视窗 (Liquid Glass Visual Card) */
.hero-visual-card {
  position: relative;
  padding: 32px;
  background: rgba(13, 24, 48, 0.65);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-xl);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), inset 0 0 20px rgba(56, 189, 248, 0.08);
}

.hero-visual-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-visual-dots {
  display: flex;
  gap: 8px;
}
.hero-visual-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.hero-visual-dot.red { background: #ef4444; }
.hero-visual-dot.yellow { background: #f59e0b; }
.hero-visual-dot.green { background: #10b981; }

.hero-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 9999px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: #34d399;
  font-size: 0.75rem;
  font-weight: 600;
}

.pulse-circle {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 8px #34d399;
  animation: pulseDot 1.5s infinite;
}

.hero-metrics-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

.hero-metric-box {
  padding: 16px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.hero-metric-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.hero-metric-val {
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  font-family: var(--font-mono);
}
.hero-metric-val span {
  font-size: 0.8125rem;
  color: var(--aurora-cyan);
  font-weight: 500;
}

.hero-stream-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.hero-stream-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.hero-stream-item-left {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  font-weight: 500;
}

.node-flag {
  font-size: 1.1rem;
}

.node-ping {
  font-size: 0.8125rem;
  font-family: var(--font-mono);
  color: #34d399;
  background: rgba(16, 185, 129, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ==========================================================================
   3. 核心功能优势 (Core Features)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.feature-card {
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: var(--glass-blur);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(56, 189, 248, 0.35);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4), 0 0 20px rgba(56, 189, 248, 0.15);
}

.feature-icon-wrap {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.15) 0%, rgba(99, 102, 241, 0.15) 100%);
  border: 1px solid rgba(56, 189, 248, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--aurora-cyan);
  transition: transform 0.3s ease;
}

.feature-card:hover .feature-icon-wrap {
  transform: scale(1.1) rotate(4deg);
}

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

.feature-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.68;
}

/* ==========================================================================
   4. 故障决策树展开交互系统 (Troubleshooting Decision Tree) - 框架84+03创新融合
   ========================================================================== */
.tree-section {
  position: relative;
  background: linear-gradient(180deg, rgba(7, 12, 24, 0) 0%, rgba(13, 22, 44, 0.45) 50%, rgba(7, 12, 24, 0) 100%);
}

.tree-container-card {
  padding: 36px;
  border-radius: var(--radius-xl);
  background: rgba(12, 22, 45, 0.7);
  border: 1px solid rgba(56, 189, 248, 0.2);
  backdrop-filter: blur(24px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}

.tree-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
  justify-content: center;
}

.tree-filter-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: all 0.25s ease;
}

.tree-filter-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  border-color: rgba(56, 189, 248, 0.3);
}

.tree-filter-btn.active {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--aurora-cyan);
  color: #ffffff;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.25);
}

.tree-nodes-wrap {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.tree-node-item {
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.08);
  overflow: hidden;
  transition: all 0.3s ease;
}

.tree-node-item.is-open {
  border-color: rgba(56, 189, 248, 0.4);
  background: rgba(255, 255, 255, 0.04);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.tree-node-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  text-align: left;
  color: #ffffff;
  font-size: 1.0625rem;
  font-weight: 600;
  cursor: pointer;
  background: transparent;
  transition: background 0.2s ease;
}

.tree-node-trigger:hover {
  background: rgba(255, 255, 255, 0.03);
}

.tree-trigger-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.tree-code-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 3px 8px;
  border-radius: 4px;
  background: rgba(56, 189, 248, 0.12);
  color: var(--aurora-cyan);
  border: 1px solid rgba(56, 189, 248, 0.25);
}

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

.tree-node-item.is-open .tree-node-icon {
  transform: rotate(180deg);
}

.tree-node-content {
  display: none;
  padding: 0 24px 24px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.tree-node-item.is-open .tree-node-content {
  display: block;
  animation: fadeInDown 0.3s ease forwards;
}

.tree-steps-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 16px;
  padding-left: 0;
  list-style: none;
}

.tree-step-card {
  display: flex;
  gap: 14px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: rgba(0, 0, 0, 0.25);
  border-left: 3px solid var(--aurora-cyan);
}

.tree-step-num {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--aurora-cyan);
  font-size: 0.875rem;
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   5. 套餐价格展示 (Pricing Section) - 100% 还原截图蓝图网格风格
   ========================================================================== */
.pricing-section {
  position: relative;
}

.pricing-cycle-switcher {
  display: inline-flex;
  align-items: center;
  padding: 5px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: 40px;
  backdrop-filter: var(--glass-blur);
}

.cycle-tab-btn {
  padding: 8px 22px;
  border-radius: 9999px;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 600;
  transition: all 0.25s ease;
}

.cycle-tab-btn:hover {
  color: #ffffff;
}

.cycle-tab-btn.active {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 2px 10px rgba(2, 132, 199, 0.4);
}

.discount-tag {
  display: inline-block;
  margin-left: 4px;
  padding: 1px 6px;
  font-size: 0.6875rem;
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
  border-radius: 9999px;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.pricing-cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

/* 蓝图网格底纹卡片 (Blueprint Graph Paper Pattern) - 对应截图设计语言 */
.plan-card {
  position: relative;
  background: #ffffff;
  border-radius: var(--radius-lg);
  padding: 40px 32px 36px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 1.5px solid #dbeafe;
  color: #0f172a;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  /* 截图中的浅蓝坐标网格纹理 */
  background-image: 
    linear-gradient(to right, rgba(2, 132, 199, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(2, 132, 199, 0.07) 1px, transparent 1px);
  background-size: 24px 24px;
}

.plan-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(2, 132, 199, 0.18);
  border-color: #38bdf8;
}

/* PLAN 02 推荐突出卡片 (特色高亮蓝框) */
.plan-card.is-featured {
  border: 2.5px solid #0284c7;
  box-shadow: 0 15px 40px rgba(2, 132, 199, 0.28);
  transform: scale(1.03);
  z-index: 2;
}

.plan-card.is-featured:hover {
  transform: scale(1.03) translateY(-8px);
}

.plan-featured-badge {
  position: absolute;
  top: 18px;
  right: 20px;
  background: #0284c7;
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 4px;
  letter-spacing: 0.04em;
}

.plan-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: #0284c7;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.plan-title {
  font-size: 1.75rem;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.plan-subtitle {
  font-size: 0.9375rem;
  color: #64748b;
  margin-bottom: 32px;
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid #e2e8f0;
}

.plan-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9375rem;
  font-weight: 600;
  color: #334155;
}

.plan-feature-check {
  color: #10b981;
  font-size: 1rem;
  font-weight: 800;
}

.plan-price-wrap {
  margin-bottom: 28px;
}

.plan-price-row {
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.plan-currency {
  font-size: 1.5rem;
  font-weight: 800;
  color: #0f172a;
}

.plan-amount {
  font-size: 2.75rem;
  font-weight: 900;
  color: #0f172a;
  font-family: var(--font-mono);
  letter-spacing: -0.03em;
  transition: all 0.25s ease;
}

.plan-period {
  font-size: 0.875rem;
  color: #64748b;
  font-weight: 500;
}

.plan-cta-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-radius: var(--radius-md);
  background: #f1f5f9;
  color: #0284c7;
  font-weight: 700;
  font-size: 1rem;
  border: 1px solid #cbd5e1;
  transition: all 0.25s ease;
  text-decoration: none;
}

.plan-card.is-featured .plan-cta-btn {
  background: #0284c7;
  color: #ffffff;
  border-color: #0284c7;
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
}

.plan-cta-btn:hover {
  background: #0284c7;
  color: #ffffff;
  border-color: #0284c7;
}

.plan-card.is-featured .plan-cta-btn:hover {
  background: #0369a1;
}

.plan-arrow {
  transition: transform 0.25s ease;
}

.plan-cta-btn:hover .plan-arrow {
  transform: translateX(4px);
}

/* ==========================================================================
   6. 使用场景与客户端配置指南 (Client Guide & Scenarios)
   ========================================================================== */
.client-tabs {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}

.client-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 600;
  transition: all 0.25s ease;
}

.client-tab-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
}

.client-tab-btn.active {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--aurora-cyan);
  color: #ffffff;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.2);
}

.client-content-card {
  padding: 40px;
  border-radius: var(--radius-xl);
  background: rgba(13, 22, 44, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: var(--glass-blur);
}

.client-steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.client-step-item {
  padding: 24px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.client-step-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--aurora-cyan), var(--primary));
  color: #040812;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-family: var(--font-mono);
}

.client-step-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.client-step-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   7. 知识文章系统精选 (Original Articles Grid)
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

.article-card {
  padding: 28px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: var(--glass-blur);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.3s ease;
}

.article-card:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(56, 189, 248, 0.35);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.8125rem;
  color: var(--aurora-cyan);
  margin-bottom: 12px;
}

.article-tag {
  background: rgba(56, 189, 248, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.article-date {
  color: var(--text-muted);
}

.article-title {
  font-size: 1.1875rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.45;
  margin-bottom: 12px;
}

.article-excerpt {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
}

.article-read-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--aurora-cyan);
}

.article-read-link:hover {
  color: #ffffff;
}

/* ==========================================================================
   8. 来自真实用户的声音 (User Reviews Section - 对应图二 3x2 网格架构与图三高保真评价框)
   ========================================================================== */
.reviews-section {
  position: relative;
}

.highlight-cyan {
  background: linear-gradient(135deg, #00f2fe 0%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.review-card {
  position: relative;
  background: rgba(13, 24, 48, 0.72);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1.5px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-xl);
  padding: 32px 28px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4), inset 0 0 16px rgba(56, 189, 248, 0.06);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.review-card:hover {
  transform: translateY(-6px);
  border-color: rgba(56, 189, 248, 0.75);
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.5), 0 0 25px rgba(56, 189, 248, 0.25);
}

.review-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.review-stars {
  color: #f59e0b;
  font-size: 1.35rem;
  letter-spacing: 3px;
  line-height: 1;
}

.review-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 5px 16px;
  border-radius: 9999px;
  border: 1.5px solid #00f2fe;
  background: rgba(0, 242, 254, 0.08);
  color: #00f2fe;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  box-shadow: 0 0 10px rgba(0, 242, 254, 0.2);
}

.review-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.review-quote {
  font-size: 1rem;
  color: #cbd5e1;
  line-height: 1.7;
  margin-bottom: 24px;
  flex-grow: 1;
}

.review-divider {
  height: 1px;
  width: 100%;
  background: rgba(255, 255, 255, 0.08);
  margin-bottom: 20px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 14px;
}

.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, #2563eb 0%, #00f2fe 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.author-avatar svg {
  width: 24px;
  height: 24px;
  fill: #ffffff;
}

.author-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.author-name {
  font-size: 1.0625rem;
  font-weight: 700;
  color: #ffffff;
}

.author-meta {
  font-size: 0.875rem;
  color: #38bdf8;
  font-weight: 500;
}

/* 用户体验反馈提交卡片 (对应图一) */
.feedback-card {
  max-width: 820px;
  margin: 56px auto 0;
  padding: 44px;
  border-radius: var(--radius-xl);
  background: rgba(13, 24, 48, 0.65);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(24px);
  text-align: center;
}

.feedback-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-top: 28px;
  text-align: left;
}

.feedback-form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feedback-form-group.full-width {
  grid-column: 1 / -1;
}

.feedback-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
}

.feedback-input, .feedback-select, .feedback-textarea {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: #ffffff;
  font-family: inherit;
  font-size: 0.9375rem;
  outline: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.feedback-input:focus, .feedback-select:focus, .feedback-textarea:focus {
  border-color: var(--aurora-cyan);
  background: rgba(255, 255, 255, 0.08);
}

.feedback-textarea {
  min-height: 110px;
  resize: vertical;
}

.feedback-submit-btn {
  grid-column: 1 / -1;
  padding: 14px 28px;
  background: var(--cta-btn-bg);
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all 0.25s ease;
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.4);
}

.feedback-submit-btn:hover {
  background: var(--cta-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(2, 132, 199, 0.6);
}

.feedback-submit-btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  transform: none;
}

.feedback-result {
  margin-top: 20px;
  padding: 14px;
  border-radius: var(--radius-sm);
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: #34d399;
  font-size: 0.9375rem;
  display: none;
  line-height: 1.6;
}

/* ==========================================================================
   9. 常见问题 (FAQ Section)
   ========================================================================== */
.faq-grid {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: var(--glass-blur);
  overflow: hidden;
  transition: all 0.25s ease;
}

.faq-item.is-open {
  border-color: rgba(56, 189, 248, 0.35);
  background: rgba(255, 255, 255, 0.05);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 24px;
  color: #ffffff;
  font-size: 1.0625rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}

.faq-question:hover {
  color: var(--aurora-cyan);
}

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

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

.faq-answer {
  display: none;
  padding: 0 24px 24px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.75;
  border-top: 1px solid rgba(255, 255, 255, 0.04);
}

.faq-item.is-open .faq-answer {
  display: block;
  animation: fadeInDown 0.3s ease forwards;
}

/* ==========================================================================
   10. 底部 CTA 横幅 (Bottom Action Banner)
   ========================================================================== */
.cta-banner-section {
  padding: 80px 0;
}

.cta-banner-card {
  padding: 56px 36px;
  border-radius: var(--radius-xl);
  background: radial-gradient(circle at 50% 0%, rgba(2, 132, 199, 0.3) 0%, rgba(13, 22, 44, 0.8) 75%);
  border: 1px solid rgba(56, 189, 248, 0.3);
  backdrop-filter: blur(24px);
  text-align: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5), 0 0 30px rgba(56, 189, 248, 0.2);
}

.cta-banner-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 850;
  color: #ffffff;
  margin-bottom: 16px;
}

.cta-banner-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

/* ==========================================================================
   11. 页脚 (Semantic Footer)
   ========================================================================== */
.site-footer {
  background: #03060d;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 72px 0 36px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 56px;
}

.footer-brand-col p {
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.7;
  margin-top: 16px;
  max-width: 320px;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 20px;
  letter-spacing: 0.02em;
}

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

.footer-link {
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-link:hover {
  color: var(--aurora-cyan);
  transform: translateX(3px);
}

.footer-bottom-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.footer-bottom-links {
  display: flex;
  gap: 20px;
}

/* ==========================================================================
   12. 响应式布局优化 (Responsive Breakpoints: 320px - 1024px)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .pricing-cards-grid {
    grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  }
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
  .plan-card.is-featured {
    transform: none;
  }
  .plan-card.is-featured:hover {
    transform: translateY(-8px);
  }
  .footer-top-grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
  }
}

@media (max-width: 768px) {
  .nav-menu, .nav-actions .btn-secondary {
    display: none !important;
  }
  .mobile-menu-btn {
    display: block !important;
  }
  .mobile-drawer {
    display: none !important;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    max-height: calc(100vh - var(--nav-height));
    overflow-y: auto;
    background: rgba(7, 12, 24, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(56, 189, 248, 0.2);
    padding: 24px;
    z-index: 999;
    box-shadow: 0 16px 36px rgba(0, 0, 0, 0.7);
  }
  .mobile-drawer.is-open {
    display: block !important;
    animation: fadeInDown 0.25s ease forwards;
  }
  .mobile-nav-list {
    display: flex;
    flex-direction: column;
    gap: 18px;
    list-style: none;
    margin-bottom: 24px;
  }
  .mobile-nav-link {
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--text-primary);
  }
  .section {
    padding: 64px 0;
  }
  .pricing-cards-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .pricing-cycle-switcher {
    flex-wrap: wrap;
    justify-content: center;
  }
  .feedback-form {
    grid-template-columns: 1fr;
  }
  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-bottom-bar {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }
  .hero-section {
    padding: 60px 0 40px;
  }
  .plan-card {
    padding: 28px 20px;
  }
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }
  .hero-cta-main, .hero-cta-sub {
    width: 100%;
    text-align: center;
  }
  .tree-container-card {
    padding: 20px 16px;
  }
}

/* ==========================================================================
   13. 无障碍与减少动效 (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;
  }
  .aurora-mesh {
    animation: none !important;
  }
}