/* ==========================================================================
   瞬云 SHUNYUN.BLOG - 工业级工程蓝图与架构线框风样式表 (CAD Blueprint Design System)
   ========================================================================== */

:root {
  --bg-blueprint-deep: #050b16;
  --bg-blueprint-dark: #081324;
  --bg-blueprint-card: #0b1a30;
  --bg-blueprint-elevated: #0f2444;
  
  --grid-line-minor: rgba(45, 114, 210, 0.08);
  --grid-line-major: rgba(56, 189, 248, 0.18);
  
  --cad-white: #f8fafc;
  --cad-white-muted: #cbd5e1;
  --cad-text-dim: #94a3b8;
  --cad-cyan: #38bdf8;
  --cad-cyan-glow: rgba(56, 189, 248, 0.35);
  --cad-yellow: #facc15;
  --cad-yellow-dim: #ca8a04;
  --cad-yellow-glow: rgba(250, 204, 21, 0.3);
  --cad-green: #10b981;
  --cad-green-glow: rgba(16, 185, 129, 0.3);
  --cad-red: #f43f5e;
  
  --border-cad-line: 1px solid rgba(56, 189, 248, 0.28);
  --border-cad-dashed: 1px dashed rgba(56, 189, 248, 0.35);
  --border-cad-yellow: 1px solid rgba(250, 204, 21, 0.4);
  
  --font-mono: "Fira Code", "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  --container-max-width: 1200px;
  --radius-sm: 3px;
  --radius-md: 6px;
  --shadow-blueprint: 0 8px 32px 0 rgba(2, 6, 23, 0.6);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  font-size: 16px;
  background-color: var(--bg-blueprint-deep);
  color: var(--cad-white);
  font-family: var(--font-sans);
  line-height: 1.6;
}

body {
  min-height: 100vh;
  background-color: var(--bg-blueprint-deep);
  /* Precision Engineering Blueprint Grid */
  background-image: 
    linear-gradient(var(--grid-line-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line-major) 1px, transparent 1px),
    linear-gradient(var(--grid-line-minor) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line-minor) 1px, transparent 1px);
  background-size: 100px 100px, 100px 100px, 20px 20px, 20px 20px;
  background-position: -1px -1px, -1px -1px, -1px -1px, -1px -1px;
  overflow-x: hidden;
  position: relative;
}

/* Top Blueprint Tech Overlay Lines */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: repeating-linear-gradient(90deg, var(--cad-yellow) 0, var(--cad-yellow) 20px, var(--cad-cyan) 20px, var(--cad-cyan) 40px, transparent 40px, transparent 50px);
  z-index: 1000;
  opacity: 0.8;
}

/* Base Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--cad-white);
}

p {
  color: var(--cad-white-muted);
}

a {
  color: var(--cad-cyan);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover {
  color: var(--cad-yellow);
  text-shadow: 0 0 8px var(--cad-yellow-glow);
}

/* Technical Layout Container */
.blueprint-container {
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
  position: relative;
}

/* Section Spacing & Blueprint Header */
.blueprint-section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
  position: relative;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--cad-yellow);
  background: rgba(250, 204, 21, 0.08);
  border: 1px solid rgba(250, 204, 21, 0.3);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.section-title {
  font-size: 2.2rem;
  line-height: 1.3;
  margin-bottom: 16px;
  color: var(--cad-white);
  font-weight: 800;
}

.section-subtitle {
  font-size: 1.05rem;
  max-width: 680px;
  margin: 0 auto;
  color: var(--cad-text-dim);
}

/* Technical CAD Line Dividers */
.blueprint-ruler {
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.4) 20%, rgba(250, 204, 21, 0.6) 50%, rgba(56, 189, 248, 0.4) 80%, transparent);
  margin: 40px auto;
  position: relative;
  max-width: 800px;
}

.blueprint-ruler::before {
  content: "+ ARCH-SPEC: SY-2026 +";
  position: absolute;
  top: -9px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-blueprint-deep);
  padding: 0 12px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cad-text-dim);
  letter-spacing: 0.15em;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.blueprint-nav {
  position: sticky;
  top: 0;
  z-index: 999;
  background: rgba(5, 11, 22, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(56, 189, 248, 0.2);
  transition: all 0.3s ease;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-schematic {
  width: 36px;
  height: 36px;
  border: 1px solid var(--cad-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: rgba(56, 189, 248, 0.08);
  box-shadow: 0 0 12px var(--cad-cyan-glow);
}

.logo-schematic::before {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px dashed var(--cad-yellow);
  transform: rotate(45deg);
}

.logo-schematic::after {
  content: "";
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--cad-cyan);
  border-radius: 50%;
}

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

.brand-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--cad-white);
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand-name span {
  color: var(--cad-yellow);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--cad-text-dim);
  letter-spacing: 0.12em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--cad-white-muted);
  position: relative;
  padding: 6px 0;
  transition: color 0.2s;
}

.nav-link:hover {
  color: var(--cad-yellow);
}

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

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

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.25s ease;
  position: relative;
  overflow: hidden;
  letter-spacing: 0.04em;
}

.btn-primary {
  background: linear-gradient(135deg, #facc15 0%, #eab308 100%);
  color: #050b16;
  border: 1px solid #fde047;
  box-shadow: 0 0 16px var(--cad-yellow-glow);
  font-weight: 700;
}

.btn-primary:hover {
  background: #fde047;
  color: #000;
  box-shadow: 0 0 24px rgba(250, 204, 21, 0.6);
  transform: translateY(-1px);
}

.btn-outline {
  background: rgba(56, 189, 248, 0.05);
  color: var(--cad-cyan);
  border: 1px solid rgba(56, 189, 248, 0.4);
}

.btn-outline:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--cad-cyan);
  box-shadow: 0 0 16px var(--cad-cyan-glow);
  color: #fff;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
}

/* Mobile Toggle & Menu */
.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid rgba(56, 189, 248, 0.3);
  color: var(--cad-white);
  padding: 8px 12px;
  font-size: 1.2rem;
  cursor: pointer;
}

.mobile-nav-menu {
  display: none;
}

/* ==========================================================================
   Hero Section - Blueprint Topology & Lead Annotations
   ========================================================================== */
.hero-section {
  padding: 70px 0 90px 0;
  text-align: center;
  position: relative;
}

.hero-meta-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 6px 16px;
  background: rgba(8, 19, 36, 0.9);
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-radius: var(--radius-sm);
  color: var(--cad-cyan);
  margin-bottom: 24px;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background: var(--cad-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--cad-green);
  animation: pulse-ping 2s infinite cubic-bezier(0, 0, 0.2, 1);
}

@keyframes pulse-ping {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1.1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 3.2rem;
  line-height: 1.18;
  font-weight: 800;
  max-width: 960px;
  margin: 0 auto 24px auto;
  color: var(--cad-white);
}

.hero-title .highlight-yellow {
  color: var(--cad-yellow);
  text-shadow: 0 0 20px var(--cad-yellow-glow);
}

.hero-title .highlight-cyan {
  color: var(--cad-cyan);
  text-shadow: 0 0 20px var(--cad-cyan-glow);
}

.hero-desc {
  font-size: 1.15rem;
  line-height: 1.7;
  max-width: 820px;
  margin: 0 auto 36px auto;
  color: var(--cad-white-muted);
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 50px;
  flex-wrap: wrap;
}

/* CAD Technical Blueprint Topology Display Box */
.topology-blueprint-frame {
  margin: 20px auto 0 auto;
  background: var(--bg-blueprint-dark);
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-blueprint), 0 0 40px rgba(56, 189, 248, 0.1);
  position: relative;
  padding: 30px 24px;
  overflow: hidden;
}

/* Blueprint Corner Crosshairs & Labels */
.blueprint-corner {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: rgba(56, 189, 248, 0.6);
  pointer-events: none;
}

.corner-tl { top: 8px; left: 10px; }
.corner-tr { top: 8px; right: 10px; }
.corner-bl { bottom: 8px; left: 10px; }
.corner-br { bottom: 8px; right: 10px; }

.blueprint-meta-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px dashed rgba(56, 189, 248, 0.25);
  padding-bottom: 12px;
  margin-bottom: 24px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cad-text-dim);
}

.blueprint-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.blueprint-meta-item strong {
  color: var(--cad-yellow);
}

/* Interactive SVG / Schematic Area */
.schematic-svg-wrap {
  width: 100%;
  max-width: 1060px;
  margin: 0 auto;
}

.schematic-svg {
  width: 100%;
  height: auto;
  display: block;
}

/* Topology Spec Chips */
.topology-specs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 30px;
  border-top: 1px solid rgba(56, 189, 248, 0.2);
  padding-top: 24px;
}

.spec-chip {
  text-align: left;
  background: rgba(11, 26, 48, 0.7);
  border: 1px solid rgba(56, 189, 248, 0.18);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  position: relative;
}

.spec-chip::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--cad-cyan);
}

.spec-chip.highlight-yellow::before {
  background: var(--cad-yellow);
}

.spec-chip-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cad-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.spec-chip-value {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--cad-white);
  margin-top: 4px;
  font-family: var(--font-mono);
}

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

.cad-card {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-sm);
  padding: 30px 24px;
  position: relative;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.cad-card:hover {
  transform: translateY(-4px);
  border-color: var(--cad-yellow);
  box-shadow: 0 12px 30px rgba(2, 6, 23, 0.7), 0 0 20px rgba(250, 204, 21, 0.15);
}

.cad-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.cad-card-id {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cad-yellow);
  background: rgba(250, 204, 21, 0.1);
  padding: 2px 8px;
  border: 1px solid rgba(250, 204, 21, 0.3);
}

.cad-card-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(56, 189, 248, 0.3);
  background: rgba(56, 189, 248, 0.05);
  color: var(--cad-cyan);
  font-size: 1.3rem;
}

.cad-card-title {
  font-size: 1.25rem;
  margin-bottom: 12px;
  color: var(--cad-white);
  font-weight: 700;
}

.cad-card-body {
  font-size: 0.95rem;
  color: var(--cad-white-muted);
  line-height: 1.65;
  flex-grow: 1;
}

.cad-card-footer {
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px dashed rgba(56, 189, 248, 0.2);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cad-cyan);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ==========================================================================
   Architecture & Tunnel Teardown (架构与加密隧道拆解)
   ========================================================================== */
.tunnel-teardown-box {
  background: var(--bg-blueprint-dark);
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-md);
  padding: 36px 30px;
  position: relative;
}

.tunnel-pipeline-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  position: relative;
  margin-top: 30px;
}

.pipeline-step {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.25);
  padding: 24px 20px;
  position: relative;
  display: flex;
  flex-direction: column;
}

.pipeline-step::after {
  content: "→";
  position: absolute;
  right: -15px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--cad-yellow);
  z-index: 2;
}

.pipeline-step:last-child::after {
  display: none;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cad-yellow);
  margin-bottom: 8px;
  font-weight: 700;
}

.step-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--cad-white);
  margin-bottom: 10px;
}

.step-details {
  font-size: 0.88rem;
  color: var(--cad-text-dim);
  line-height: 1.6;
}

.step-tech-tag {
  margin-top: auto;
  padding-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--cad-cyan);
}

/* ==========================================================================
   Live Node Latency Monitor (全球节点延迟与健康状态)
   ========================================================================== */
.latency-monitor-box {
  background: var(--bg-blueprint-dark);
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-md);
  padding: 30px;
  box-shadow: var(--shadow-blueprint);
}

.monitor-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.monitor-status-pill {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  color: var(--cad-green);
}

.latency-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.node-card {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.2);
  padding: 20px;
  border-radius: var(--radius-sm);
  position: relative;
  transition: border-color 0.25s;
}

.node-card:hover {
  border-color: var(--cad-cyan);
}

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

.node-title-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.node-flag {
  font-size: 1.2rem;
}

.node-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--cad-white);
}

.node-code {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--cad-text-dim);
}

.node-status-badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  padding: 2px 8px;
  border-radius: 2px;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.4);
  color: var(--cad-green);
  text-transform: uppercase;
}

.node-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  border-top: 1px dashed rgba(56, 189, 248, 0.18);
  padding-top: 14px;
  text-align: center;
}

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

.metric-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--cad-text-dim);
}

.metric-value {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--cad-yellow);
}

.metric-value.green {
  color: var(--cad-green);
}

.metric-value.cyan {
  color: var(--cad-cyan);
}

/* ==========================================================================
   Pricing Plans (套餐价格板块)
   ========================================================================== */
.pricing-switcher-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.billing-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--cad-text-dim);
  cursor: pointer;
}

.billing-label.active {
  color: var(--cad-white);
}

.pricing-toggle {
  position: relative;
  width: 56px;
  height: 28px;
  background: var(--bg-blueprint-dark);
  border: 1px solid var(--cad-cyan);
  border-radius: 14px;
  cursor: pointer;
  padding: 2px;
  transition: background 0.3s;
}

.toggle-knob {
  width: 22px;
  height: 22px;
  background: var(--cad-yellow);
  border-radius: 50%;
  transition: transform 0.25s ease;
  box-shadow: 0 0 8px var(--cad-yellow-glow);
}

.pricing-toggle.yearly .toggle-knob {
  transform: translateX(28px);
}

.discount-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  background: rgba(250, 204, 21, 0.15);
  border: 1px solid var(--cad-yellow);
  color: var(--cad-yellow);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-sm);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: var(--cad-cyan);
  box-shadow: var(--shadow-blueprint), 0 0 25px rgba(56, 189, 248, 0.15);
}

.pricing-card.featured {
  border-color: var(--cad-yellow);
  background: linear-gradient(180deg, rgba(250, 204, 21, 0.04) 0%, var(--bg-blueprint-card) 40%);
  box-shadow: var(--shadow-blueprint), 0 0 30px rgba(250, 204, 21, 0.18);
}

.featured-ribbon {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--cad-yellow);
  color: #050b16;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 800;
  padding: 3px 14px;
  border-radius: 2px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}

.tier-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--cad-white);
  margin-bottom: 6px;
}

.tier-desc {
  font-size: 0.85rem;
  color: var(--cad-text-dim);
  min-height: 38px;
  margin-bottom: 20px;
}

.tier-price-box {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px dashed rgba(56, 189, 248, 0.2);
}

.tier-currency {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--cad-yellow);
  vertical-align: top;
}

.tier-price {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--cad-white);
  line-height: 1;
}

.tier-period {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cad-text-dim);
}

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

.tier-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--cad-white-muted);
  margin-bottom: 12px;
}

.tier-feature-item svg {
  color: var(--cad-green);
  flex-shrink: 0;
  margin-top: 3px;
}

.tier-cta {
  width: 100%;
}

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

.testimonial-card {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: var(--radius-sm);
  padding: 28px 24px;
  position: relative;
  display: flex;
  flex-direction: column;
}

.testimonial-quote {
  font-size: 0.95rem;
  line-height: 1.68;
  color: var(--cad-white-muted);
  margin-bottom: 20px;
  flex-grow: 1;
  position: relative;
}

.testimonial-quote::before {
  content: "“";
  font-family: Georgia, serif;
  font-size: 2.2rem;
  color: rgba(56, 189, 248, 0.3);
  position: absolute;
  top: -15px;
  left: -8px;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px dashed rgba(56, 189, 248, 0.18);
  padding-top: 16px;
}

.author-avatar {
  width: 42px;
  height: 42px;
  background: var(--bg-blueprint-elevated);
  border: 1px solid var(--cad-cyan);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--cad-yellow);
}

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

.author-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--cad-white);
}

.author-title {
  font-size: 0.78rem;
  color: var(--cad-text-dim);
  font-family: var(--font-mono);
}

/* ==========================================================================
   FAQ Section (常见问题板块)
   ========================================================================== */
.faq-wrap {
  max-width: 880px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.22);
  margin-bottom: 14px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.2s;
}

.faq-item.active {
  border-color: var(--cad-yellow);
}

.faq-question {
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--cad-white);
  gap: 16px;
  user-select: none;
}

.faq-toggle-icon {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--cad-cyan);
  transition: transform 0.25s ease;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(45deg);
  color: var(--cad-yellow);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease-out, padding 0.25s ease;
  font-size: 0.95rem;
  color: var(--cad-white-muted);
  line-height: 1.7;
  padding: 0 24px;
  background: rgba(5, 11, 22, 0.4);
}

.faq-item.active .faq-answer {
  padding: 0 24px 20px 24px;
  max-height: 400px;
}

/* ==========================================================================
   Knowledge Base & Guides (知识库与教程板块)
   ========================================================================== */
.kb-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.kb-card {
  background: var(--bg-blueprint-card);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-sm);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  text-decoration: none;
}

.kb-card:hover {
  transform: translateY(-4px);
  border-color: var(--cad-yellow);
  box-shadow: 0 10px 24px rgba(2, 6, 23, 0.8), 0 0 16px rgba(250, 204, 21, 0.15);
}

.kb-card-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cad-cyan);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.kb-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--cad-white);
  line-height: 1.4;
  margin-bottom: 10px;
}

.kb-card-desc {
  font-size: 0.85rem;
  color: var(--cad-text-dim);
  line-height: 1.6;
  margin-bottom: 16px;
  flex-grow: 1;
}

.kb-card-meta {
  border-top: 1px dashed rgba(56, 189, 248, 0.18);
  padding-top: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--cad-yellow);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.blueprint-footer {
  border-top: 1px solid rgba(56, 189, 248, 0.25);
  background: #03070f;
  padding: 60px 0 30px 0;
  position: relative;
  font-size: 0.88rem;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand p {
  margin-top: 14px;
  color: var(--cad-text-dim);
  max-width: 320px;
  line-height: 1.65;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--cad-yellow);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 18px;
}

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

.footer-link {
  color: var(--cad-white-muted);
  font-size: 0.86rem;
}

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

.footer-bottom {
  border-top: 1px dashed rgba(56, 189, 248, 0.18);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cad-text-dim);
}

/* Responsive Media Queries */
@media (max-width: 1100px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .kb-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .topology-specs-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .tunnel-pipeline-steps {
    grid-template-columns: repeat(2, 1fr);
  }
  .pipeline-step::after {
    display: none;
  }
}

@media (max-width: 768px) {
  .advantages-grid,
  .latency-grid,
  .testimonials-grid,
  .footer-top-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-grid,
  .kb-grid,
  .topology-specs-grid,
  .tunnel-pipeline-steps {
    grid-template-columns: 1fr;
  }
  
  .hero-title {
    font-size: 2.2rem;
  }
  
  .nav-links {
    display: none;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .mobile-nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-blueprint-dark);
    border-bottom: 1px solid var(--cad-cyan);
    padding: 20px;
    flex-direction: column;
    gap: 16px;
  }
  
  .mobile-nav-menu.open {
    display: flex;
  }
}